Author name code: menzel
ADS astronomy entries on 2022-09-14
author:"Menzel, Donald H."
------------------------------------------------------------------------
Title: Critical Fluctuations Beyond the Quantum Phase
Transition in Dzyaloshinskii-Moriya Helimagnets Mn1
-xFexSi
Authors: Grigoriev, S. V.; Utesov, O. I.; Chubova, N. M.; Dewhurst,
C. D.; Menzel, D.; Maleyev, S. V.
Bibcode: 2021JETP..132..588G
Altcode:
Polarized small-angle neutron scattering was used for studying
of critical fluctuations in the Dzyaloshinskii-Moriya helimagnets
Mn1 -xFexSi with x = 0.10, 0.15,
0.20. The Mn1 -xFexSi compounds are
helically ordered below Tc and show a helical fluctuation
regime above Tc in a wide range up to TDM. The
critical temperatures Tc and TDM decrease with
x and tend to 0 at x = 0.11 and 0.17, respectively. It was shown
experimentally that three samples reveal properties of fluctuations in
different regimes. The sample with x = 0.10 provides sharp narrow peak
in polarized SANS maps for temperatures near Tc and in the
ordered phase, whereas in the one with x = 0.15 critical fluctuations
are suppressed by the disorder which destroys long-range magnetic order,
corresponding scattering peaks being substantially wider than for x =
0.10. For the sample with x = 0.20 even at lowest temperatures only
traces of the half-moon scattering patterns are visible. The degree
of the scattering polarization is close to 1 for all three samples
meaning that the corresponding helical fluctuations are chiral. The
Mn1 -xFexSi compounds represent
an example of the system where ferromagnetic exchange approaches
zero but Dzyaloshinskii-Moriya interaction is finite and provides
chiral rotation of spins in magnetic fluctuations. We argue at the
qualitative level that observed peculiarities can be attributed to
defect antiferromagnetic bonds which are added to the system by Fe
ions and lead to finite correlation length of the spiral at small
temperatures for x > xc.
Title: A Field Guide to the Stars and Planets
Authors: Pasachoff, J. M.; Menzel, D. H.
Bibcode: 1998fgsp.book.....P
Altcode:
The standard field guide for amateur observing; also usable for
reference at professional telescopes. Many useful tables.
Title: Stars and planets
Authors: Pasachoff, Jay M.; Menzel, Donald H.
Bibcode: 1992stpl.book.....P
Altcode: 1992QB64.P37.......
No abstract at ADS
Title: Quantum effects in the sticking of Ne on a flat metal surface
Authors: Schlichting, H.; Menzel, D.; Brunner, T.; Brenig, W.; Tully,
J. C.
Bibcode: 1988PhRvL..60.2515S
Altcode:
The sticking coefficient of thermal neon atoms on a flat Ru(001) surface
(Ts=7 K) is found experimentally to be very low and strongly
dependent on gas temperature (1×10-3 to 8×10-3
for Tg from 600 to 30 K) on the clean surface, and to
increase strongly with coverage to about 0.7. The zero-coverage values
are incompatible with classical mechanical theory, irrespective of
assumed interaction parameters, requiring substantial zero-phonon
scattering. Calculations treating the energy transfer to phonons
quantum mechanically can reproduce the data with reasonable parameters.
Title: Book-Review - a Field Guide to Stars and Planets
Authors: Menzel, D. H.; Pasachoff, J. M.; Tirion, W.; Soltynski, M.
Bibcode: 1988MNSSA..47..161M
Altcode:
No abstract at ADS
Title: Book-Review - a Field Guide to the Stars and Planets
Authors: Menzel, D. H.
Bibcode: 1984AExpr...1Q.111M
Altcode:
No abstract at ADS
Title: Book-Review - a Field Guide to the Stars and Planets
Authors: Menzel, D. H.; Pasachoff, J. M.
Bibcode: 1984S&T....68..227M
Altcode:
No abstract at ADS
Title: Book-Review - Field Guide to Stars and Planets - ED.2
Authors: Menzel, D. H.; Pasachoff, J. H.
Bibcode: 1984Sci...224..743M
Altcode:
No abstract at ADS
Title: Book-Review - a Field Guide to the Stars and Planets - ED.2
Authors: Menzel, D. H.; Pasachoff, J. M.
Bibcode: 1984Natur.309..477M
Altcode:
No abstract at ADS
Title: Book-Review - a Field Guide to the Stars and Planets
Authors: Menzel, D. H.; Pasachoff, J. M.; de Jager, C.
Bibcode: 1984SSRv...38..185M
Altcode:
No abstract at ADS
Title: Book-Review - a Field Guide to the Stars and Planets - ED.2
Authors: Menzel, D.; Pasachoff, J.
Bibcode: 1984Mercu..13S..86M
Altcode:
No abstract at ADS
Title: A field guide to the stars and planets
Authors: Menzel, Donald Howard; Pasachoff, Jay M.
Bibcode: 1983fgts.book.....M
Altcode:
No abstract at ADS
Title: Il nostro sole.
Authors: Menzel, D. H.
Bibcode: 1981ins..book.....M
Altcode:
No abstract at ADS
Title: The UFO Enigma (Book Review)
Authors: Menzel, D. H.; Taves, E. H.
Bibcode: 1979ApL....20...23M
Altcode:
No abstract at ADS
Title: Charles Greeley Abbot.
Authors: Menzel, D. H.
Bibcode: 1977QJRAS..18..136M
Altcode:
No abstract at ADS
Title: Orion, un vaste complexe de matière interstellaire ionisée
Authors: Menzel, Donald H.
Bibcode: 1977LAstr..91...50M
Altcode:
No abstract at ADS
Title: The UFO enigma.
Authors: Menzel, D. H.; Taves, E. H.
Bibcode: 1977ufen.book.....M
Altcode:
No abstract at ADS
Title: A New Radio Telescope for Sweden
Authors: Menzel, Donald H.
Bibcode: 1976S&T....52..240M
Altcode:
No abstract at ADS
Title: A field guide to the stars and planets.
Authors: Menzel, D. H.
Bibcode: 1975fgts.book.....M
Altcode:
No abstract at ADS
Title: 15.5. Kepler's place in science fiction
Authors: Menzel, Donald H.
Bibcode: 1975VA.....18..895M
Altcode:
No abstract at ADS
Title: Superstars and the black-hole myth.
Authors: Menzel, D. H.
Bibcode: 1975MSRSL...9..343M
Altcode: 1975apes.conf..343M; 1975assp.conf..343M
It is argued that the equation for the gravitational radius
of a black hole derived from the Einstein field equations is
entirely a mathematical relationship and that black holes cannot
exist. Schwarzschild's (1916) two exact solutions to the field
equation for gravitation are reviewed, and several general solutions
are presented which show that a black hole can have any radius,
depending on the value arbitrarily adopted for the constant n in
the denominator of the gravitational-radius equation. The deflection
of light rays near the sun is analyzed along with the gravitational
redshift predicted by general relativity, and it is suggested that
the proper value of n should be infinite, indicating that a black
hole must have zero radius. A derivation is given for the Yilmaz
metric, which disposes of the concept of black holes but allows red
holes, infrared holes, and radio holes produced as a consequence of
the gravitational redshift. This metric also allows superstars with
masses as high as a billion solar masses. A quantitative model of such
a superstar is presented.
Title: Kepler's inventions, views and visions.
Authors: Adam, A.; Prager, F.; Nitschke, A.; Seck, F.; Menzel, D. H.;
Sagan, C.; Veverka, J.; Pollack, J. B.; Gehrels, T.
Bibcode: 1975kfhy.conf..881A
Altcode:
No abstract at ADS
Title: Gyron Field-gravitational analogue of magnetic force
Authors: Salisbury, W. W.; Menzel, D. H.
Bibcode: 1974Natur.252..664S
Altcode:
AN electrostatic field E in a stationary coordinate system, when
referred to a moving coordinate system, can produce both an electric
field E *, and a magnetic field B *. If v
is the uniform velocity of motion, perpendicular to E, then by the
usual Lorentz transformation: where β=v/c. Consider two stationary
point masses, m 1 and m 2, with respective
electric charges q 1 and q 2. Suppose that
the particles are located at 0, r/2, 0 and 0, -r/2, 0 in a system
of Cartesian coordinates. If the masses and charges are chosen so
that the force of electrostatic repulsion exactly balances that of
gravitational attraction, then where G is the constant of gravitation
and ɛ0 is the electrical permittivity of space. Positive
signs indicate repulsion and negative signs attraction.
Title: Research study on dynamics of the solar atmosphere
Authors: Bell, B.; Menzel, D. H.
Bibcode: 1974hco..rept.....B
Altcode:
This report summarizes studies carried out in magnetohydrodynamics and
a new form of gravitational force. It describes coronal studies at
two eclipses, reviews an attempt to verify (with negative results)
a finding by Gnevyshev that the sunspot cycle on the average
has a double maximum, and covers research in the general area of
solar-terrestrial relations. Relationships between the intensity
of the extreme ultraviolet (EUV) emission-line corona, the level of
geomagnetic activity, and the velocity of the solar wind are discussed.
Title: Planetary nebulae
Authors: Menzel, D. H.
Bibcode: 1974ESRv...10...87M
Altcode:
No abstract at ADS
Title: Instrumentation in astronomy II : seminar-in-depth, March 4-6,
1974, Tucson, Arizona
Authors: Menzel, Donald Howard; Larmore, Lewis; Crawford, David
Livingstone
Bibcode: 1974iasm.book.....M
Altcode: 1974QB86.I583......
No abstract at ADS
Title: Instrumentation in astronomy II; Proceedings of the
Seminar-in-Depth, Tucson, Ariz., March 4-6, 1974
Authors: Menzel, D. H.; Larmore, L.; Crawford, D.
Bibcode: 1974SPIE...44.....M
Altcode:
Topics discussed include the Large Space Telescope for observations of
the solar system, the evolution of the astronomical X-ray telescope,
a narrow-angle telescope for visual imaging of Venus and Mercury, a
balloon-borne far-infrared telescope, an airborne infrared telescope,
a multiple-mirror telescope consisting of six telescopes supported
by a single mount, an automated photometric telescope with a single
minicomputer performing all supervisory operations, a high-precision
48-in. telescope for use as a laser ranger, an image tube which
uses a self-scanned diode array to detect imaged photoelectrons,
a simple quadrant detector used as a sensing element for the guidance
of optical telescopes, and an image converter which uses a microchannel
electron multiplier plate coupled to a large-area resistive anode. Other
instruments discussed include a converter of thermal images into light
images, concave-grating spectrometers, a Michelson interferometer used
as a spectrometer, an extreme ultraviolet spectrograph, a photoelectric
spectroheliometer, an X-ray spectrographic telescope, and a white-light
coronagraph. Individual items are announced in this issue.
Title: Guia de campo de las estrellas Y LOS planetas de LOS
hemisferios Norte Y Sur : incluyendo la luna, LOS satelites, LOS
cometas Y otros aspectos del universo
Authors: Menzel, Donald Howard
Bibcode: 1974gcep.book.....M
Altcode: 1974QB64.M418......
No abstract at ADS
Title: Instrumentation in astronomy : 2 : 1974
Authors: Menzel, Donald H.; Larmore, Lewis; Crawford, David
Bibcode: 1974inas.conf.....M
Altcode:
No abstract at ADS
Title: The Escape of Planetary Atmospheres
Authors: Menzel, D. H.
Bibcode: 1974IAUS...65...37M
Altcode:
No abstract at ADS
Title: Pulsar radiation as magnetic-dipole synchrotron emission.
Authors: Menzel, D. H.; Salisbury, W. W.
Bibcode: 1973LIACo..18..219M
Altcode: 1973MSRSL...5..219M
No abstract at ADS
Title: A field guide to the stars and planets : including the moon,
satellites, comets, and other features of the universe
Authors: Menzel, Donald Howard
Bibcode: 1973fgsp.book.....M
Altcode: 1973QB64.M4........
No abstract at ADS
Title: Les nébuleuses planétaires. Communications présentées au
dix-huitième Colloque International d'Astrophysique, tenu à Liège,
les 26, 27 et 28 juin 1972.
Authors: Remy-Battiau, L.; Vreux, J. M.; Menzel, D. H.
Bibcode: 1973LIACo..18.....R
Altcode: 1973MSRSL...5.....R
No abstract at ADS
Title: Survey of the Universe
Authors: Menzel, Donald H.
Bibcode: 1972AmJPh..40..364M
Altcode:
No abstract at ADS
Title: The history of astronomical spectroscopy.. I. Qualitative
chemical analysis and radial velocities.
Authors: Menzel, D. H.
Bibcode: 1972NYASA.198..225M
Altcode:
No abstract at ADS
Title: The history of astronomical spectroscopy II. Quantitative
chemical analysis and the structure of the solar atmosphere.
Authors: Menzel, D. H.
Bibcode: 1972NYASA.198..235M
Altcode:
No abstract at ADS
Title: The sun, moon and planets as observed from space vehicles.
Authors: Menzel, D. H.
Bibcode: 1972MNSSA..31...51M
Altcode:
No abstract at ADS
Title: Filamentary Structure of Planetary Nebulae
Authors: Menzel, Donald H.
Bibcode: 1971spas.conf..190M
Altcode: 1971NBSSP.353..190M
No abstract at ADS
Title: Report on Lunar Nomenclature by The Working Group of Commission
17 of the IAU
Authors: Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B.
Bibcode: 1971SSRv...12..136M
Altcode:
No abstract at ADS
Title: Motion picture record of the 7 March 1970 total solar eclipse.
Authors: Pasachoff, J. M.; Menzel, D. H.
Bibcode: 1971BAAS....3R.263P
Altcode:
No abstract at ADS
Title: Astronomy
Authors: Menzel, Donald Howard; Yu, Ching-Sung
Bibcode: 1971astr.book.....M
Altcode: 1971QB44.2.M45.....
No abstract at ADS
Title: Guide des étoiles et des planètes.
Authors: Menzel, D. H.; Egger, M.; Egger, F.; Couderc, P.
Bibcode: 1971guid.book.....M
Altcode:
No abstract at ADS
Title: The determination of coronal ,polarization.
Authors: Menzel, D. H.
Bibcode: 1971tmp..conf..245M
Altcode:
No abstract at ADS
Title: Survey of the universe.
Authors: Menzel, D. H.; Whipple, F. L.; de Vaucouleurs, G.
Bibcode: 1971suun.book.....M
Altcode:
No abstract at ADS
Title: Astronomie, een nieuw profiel van het heelal.
Authors: Menzel, D. H.
Bibcode: 1971aenp.book.....M
Altcode:
No abstract at ADS
Title: The Outer Corona at the Eclipse of March 7, 1970
Authors: Menzel, Donald H.
Bibcode: 1970Natur.226.1143M
Altcode:
No abstract at ADS
Title: A system for recording the polarization of extended
astronomical objects.
Authors: Menzel, D. H.; Salisbury, W. W.; Fernald, D. L.
Bibcode: 1970ApOpt...9.2648M
Altcode:
No abstract at ADS
Title: Coronal Polarization and Intensity at the November 12, 1966
Solar Eclipse
Authors: Arnquist, Warren N.; Menzel, Donald H.
Bibcode: 1970SoPh...11...82A
Altcode:
The 1966 Douglas Solar Eclipse Expedition obtained photographic records
of the intensity and polarization of the solar corona on November 12,
from a site at Chiguata, Peru. The present paper amplifies a preliminary
account in a special publication (Proceedings: Eclipse Symposium,
Sao Jose dos Campos, February 5-9, 1968, in press). Here we shall
give a more complete description of the equipment, its calibration,
methods of reduction, and the results obtained. We compare the observed
intensities and polarizations with those predicted by van de Hulst
and point out structure indicated by the polarization data. These
observations reveal the existence of complicated structures with
intensities and polarizations both higher and lower than required by
the van de Hulst model. In general high intensities correlate with high
polarizations and low intensities with low polarization. However, some
instances occur where seemingly normal intensities are associated with
lower polarizations and low intensities with high polarizations. We
account for these discrepancies in terms of electron concentrations
along the line of sight, which do not occur in the simplified model
corona. Further, we suggest that the existence of structure, such as
streamers, rays, and so on, in the outer corona indicates that the
current models tend to underestimate the importance of the K corona
in this region.
Title: Survey of the universe
Authors: Menzel, Donald H.; Whipple, Fred L.; de Vaucouleurs, Gerard
Bibcode: 1970suun.book.....M
Altcode: 1970QB43.2.M45.....
No abstract at ADS
Title: Astronomy
Authors: Menzel, Donald Howard; Yu, Ching-Sung
Bibcode: 1970astr.book.....M
Altcode: 1970QB44.2.M45.....
No abstract at ADS
Title: Laser Action in Non-Lte Atmospheres
Authors: Menzel, D. H.
Bibcode: 1970sfss.coll..134M
Altcode: 1970IAUCo...2..134M
No abstract at ADS
Title: Eclipse instrumentation for the solar corona.
Authors: Menzel, D. H.; Pasachoff, J. M.
Bibcode: 1970ApOpt...9.2626M
Altcode:
No abstract at ADS
Title: Coronal Polarization and Structure at the Total Solar Eclipse
of 22 September 1968
Authors: Schatten, Kenneth H.; Menzel, Donald H.; Pasachoff, Jay M.
Bibcode: 1969BAAS....1Q.261S
Altcode:
No abstract at ADS
Title: Osciliator Strengths, f, for High-Level Transitions in Hydrogen
Authors: Menzel, Donald H.
Bibcode: 1969ApJS...18..221M
Altcode:
The calculation of transition probabilities for high4evel transitions in
hydrogen proceeds most easily from a rapidly converging new formula. Two
tables off-values for transitions n + C n cover the follow- ing
ranges. Table 1: n = 50 900; C = 1, 2 6. Table 2: n = 1, 2 50; C = 1,
2 48. Simple asymptotic formulas exist for transitions of large n and
small C. Thefs obey the sum rule f = 1, despite the fact that many of
the f's are much greater than unity. The paradox is resolved by the
necessity of subtracting f-values for downward transitions.
Title: Radio Emission from High-Level Transitions in Hydrogen
Authors: Menzel, D. H.
Bibcode: 1969RSPTA.264..249M
Altcode:
No abstract at ADS
Title: Temperature Distribution of the Moon
Authors: Menzel, D. H.
Bibcode: 1969RSPTA.264..141M
Altcode:
New techniques and instrumentation have been developed for the
measurement of lunar surface temperatures. The infrared pyrometer has
a resolution of about 10 seconds of arc. Special computing methods
permit precise determination of the spots being measured on the lunar
surface. A theoretical study has enabled the lunar surface temperature
and its variation to be predicted during a lunation and during total
eclipses of the Moon for a number of models. These include surfaces of
solid rock, porous rock, dust, rubble, and various surfaces overlaid
with different depths of dust. Certain areas, like the crater Tycho,
appear to have no appreciable insulating layer of dust, although the
environs may have some dust cover of indefinite thickness. Looking
further to the future, we have calculated the temperature of the lunar
surface during and immediately after the landing of the manned vehicle
known as the Lunar Excursion Module, or LEM. High temperatures will
result from the exhaust flame of the retro-rocket, of some 1500 to
1600 degrees K immediately below the LEM. However, the cooling will
be rapid and the astronauts could safely leave the craft 5 or 10 min
after set-down.
Title: 38. A Proposed Astrophysical Model for Symbiotic Objects
Authors: Menzel, D. H.
Bibcode: 1969LIACo..15..341M
Altcode: 1969MSRSL..17..341M
No abstract at ADS
Title: The escape of planetary atmospheres.
Authors: Menzel, D. H.
Bibcode: 1969BAAS....1Q.217M
Altcode:
No abstract at ADS
Title: The role of collisions in the production of forbidden emission
transitions.
Authors: Menzel, D. H.
Bibcode: 1969MSRSL..25..113M
Altcode: 1969tisa.conf..113M
No abstract at ADS
Title: 13. The Role of Collisions in the Production of Forbidden
Emission Transitions
Authors: Menzel, D. H.
Bibcode: 1969LIACo..15..113M
Altcode: 1969MSRSL..17..113M
No abstract at ADS
Title: The nature of solar flares
Authors: Menzel, D. H.
Bibcode: 1969sfsr.conf..363M
Altcode:
No abstract at ADS
Title: The moon as an abode of life?
Authors: Menzel, D. H.
Bibcode: 1969PAPhS.113..102M
Altcode:
No abstract at ADS
Title: A proposed astrophysical model for symbiotic objects.
Authors: Menzel, D. H.
Bibcode: 1969MSRSL..25..341M
Altcode: 1969tisa.conf..341M
No abstract at ADS
Title: Remarks at Concluding Dinner
Authors: Menzel, D. H.
Bibcode: 1969LIACo..15..409M
Altcode: 1969MSRSL..17..409M
No abstract at ADS
Title: Multicolor Photoelectric Photometry of the Brighter
Planets. III. Observations from Boyden Observatory
Authors: Irvine, William M.; Simon, Theodore; Menzel, Donald H.;
Pikoos, C.; Young, Andrew T.
Bibcode: 1968AJ.....73..807I
Altcode:
Results of a program of photoelectric photometry of Mercury,
Venus, Mars, Jupiter, and Saturn between 1963 and 1965 are
presented. Observations were made in 10 narrow bands between 3150
A and 1.06 and in UB V. Phase curves and monochromatic albedos are
determined. The results are compared with previous investigations. For
Mercury, the portion of the visual phase curve observed is in good
agreement with the results of Danjon; the spectral reflectivity is
similar to that of the moon. The visual phase function of Venus shows
less forward scattering than was found by previous investigators. The
spectral reflectivity of Venus depends strongly on phase angle,
the planet becoming much bluer at large phase angles. The radio-
metric Bond albedo is estimated to be A* (9) = 0.77+0.07. No anomalous
brightening at opposition was observed for the Martian opposition in
1965. Longitudinal variations for Mars are quite prominent for X>
6000 A. The present data yield a radiometric Bond albedo A* (6') =
0.24, which may be uncertain by +0.05. The observations of Jupiter
and Saturn agree reasonably well with those obtained by Irvine et al.
Title: On the Obliteration of Strong Fraunhofer Lines by Electron
Scattering in the Solar Corona
Authors: Menzel, Donald H.; Pasachoff, Jay M.
Bibcode: 1968PASP...80..458M
Altcode:
No abstract at ADS
Title: R.A.S.C. Papers- Classification of Solar Prominences for
Sun-spot Cycle No. 19 (1955-1964)
Authors: Menzel, Donald H.; Jones, F. Shirley
Bibcode: 1968JRASC..62R.124M
Altcode: 1968JRASC..62R.121M
No abstract at ADS
Title: Multicolor photoelectric photometry of the brighter
planets. II. Observations from le Houga Observatory.
Authors: Irvine, W. M.; Simon, T.; Menzel, D. H.; Charon, J.; Leconte,
G.; Griboval, P.; Young, A. T.
Bibcode: 1968AJ.....73..251I
Altcode:
No abstract at ADS
Title: Oscillator Strengths for High-level Transitions in Hydrogen
Authors: Menzel, Donald H.
Bibcode: 1968Natur.218..756M
Altcode:
TRANSITIONS between high quantum levels of atomic hydrogen can produce
spectral lines in the radio region. Observers have detected a number of
such emissions from hydrogen gas in various radio sources. Theoretical
interpretation of such observations requires knowledge of the oscillator
strengths fn+c,n for transitions described by the quantum
transition n+c-->n. For n large and c small, the fs follow the
asymptotic formula with Jc(c) is the Bessel function of
equal order and argument and J'c(c) is the first derivative
with respect to the argument. Table 1 contains a few representative
values of M(c).
Title: Multicolor Photoelectric Photometry of the Brighter Planets.
Authors: Irvine, William M.; Simon, Theodore; Menzel, Donald H.
Bibcode: 1968AJS....73...19I
Altcode:
Preliminary results are reported from a 3-yr program of photoelectric
photometry undertaken to obtain phase curves, monochromatic albedos,
and radio- metric albedos for Mercury, Venus, Mars, Jupiter, Saturn
and the moon. Observations were made in 10 narrow bands isolated
by interference filters between 3150A and 1.06 ~ plus UBV. Both a
northern hemisphere site (the Le Houga Observatory in France) and
a southern hemisphere site (Boyden Observatory in South Africa) were
used. For Venus, results from both sites near quadrature indicate that,
relative to the sun, Venus is fainter at a wavelength of 1.06 ~ than
at X6250 by 0.07 +0.03 mag. Phase coefficients at these wavelengths
appear to be similar, so that this result probably holds also at full
phase. For Mars, good agreement is obtained with previous workers for
the geometric albedo, but phase coefficients are somewhat higher. As
a result values for the monochromatic Bond albedo for Mars are less
than those which have been suggested by de Vaucouleurs for N > 6000
A. Longitudinal variations are quite prominent for Mars at wavelengths
longer than 6000 A, the amplitude of these increasing to a wavelength
of about 8000 A and then remaining roughly constant to 1.06 ~. For
Jupiter, values of the geometric albedo agree quite well with those
given by Harris if they are normalized to our value of V(1 ,0) = -9.39.
Title: A Magnetohydrostatic Model of the Solar Corona.
Authors: Menzel, Donald H.
Bibcode: 1968AJS....73T..71M
Altcode:
Assume that the sun contains electric currents and an associated
magnetic field that resembles that of a dipole at large distances. The
equation of magnetohydrostatics, applied to a coronalike atmosphere,
uniquely requires that the temperature follow the law T=GMm
(a2+r2)/7kr3, (1) where G is the constant of gravity, M the solar mass,
m the mean molecular mass, k Boltzmann's constant, r the radius and a a
parameter specifying the distance of the current loop from the center
of the sun. We may take a r0/4, where r0 is the solar radius. Then,
with m~10-24g, we find that the surface temperature is of the order of
2 X 10~ 0K, and varies about as the inverse radius. It is remarkable
that T is independent of latitude and of the strength, H, of the
magnetic field at the pole. The electron density becomes r a2+r02 9/2
105H2a2r5(a2+r02)3 sin20 n~=n0 - + 6 (2) r0 a2+r2 3 2~GMm (a2 + r2) The
quantity n0 which represents the electron density at r=r0 for the pole,
0=0, we take from observation as 1.8 X 108. For the reasonable field
of 3 G, the surface electron density at the equator (0=900) contributed
by the second term is 1.1 X 108. Note that the electron density varies
about as r~6 and r-7 for the two respective terms. Observationally,
an analysis by Baumbach sets this variation as r-~. The simple theory,
therefore, indicates that a corona, supported by a magnetic field,
would have to possess characteristics of temperature and density closely
corresponding to those of the real corona. The research reported in this
paper was sponsored by the Air Force Cambridge Research Laboratories,
Office of Aerospace Research, under Contract AF19628-67-C0247, but
the report does not necessarily reflect endorsement by the sponsor.
Title: The Role of Magnetic Fields in the Origin and Structure of
Planetary Nebulae
Authors: Menzel, D. H.
Bibcode: 1968IAUS...34..279M
Altcode:
No abstract at ADS
Title: Long-Period Variables and Planetary Nebulae
Authors: Menzel, D. H.
Bibcode: 1968IAUS...34..386M
Altcode:
No abstract at ADS
Title: Principles of atomic spectra
Authors: Shore, Bruce W.; Menzel, Donald H.
Bibcode: 1968pas..book.....S
Altcode:
No abstract at ADS
Title: Sunspots and Magnetohydrodynamic Flows
Authors: Anderson, G. F.; Menzel, D. H.
Bibcode: 1968IAUS...35..142A
Altcode:
No abstract at ADS
Title: Theory of the Solar Corona
Authors: Menzel, D. H.
Bibcode: 1968ApL.....1..195M
Altcode:
No abstract at ADS
Title: Buchbesprechung über: Principles of Atomic
Spectra. (Ref. R. LINCKE)
Authors: Shore, B. W.; Menzel, D. H.
Bibcode: 1968ZA.....69..245S
Altcode:
No abstract at ADS
Title: The nature of solar flares
Authors: Menzel, D. H.
Bibcode: 1968mmsf.conf..183M
Altcode:
No abstract at ADS
Title: La Lune (The Moon)
Authors: Menzel, D. H.
Bibcode: 1968IAUTB..13..103M
Altcode:
No abstract at ADS
Title: Review of Publications- The Nature of the Lunar Surface edited
Authors: Hess, W. N.; Menzel, D. H.; O'Keefe, J. A.
Bibcode: 1967JRASC..61..200H
Altcode:
No abstract at ADS
Title: Lunar Introduction
Authors: Menzel, D. H.
Bibcode: 1967Natur.214..747M
Altcode:
No abstract at ADS
Title: The surfaces of the Moon, Mars and Venus
Authors: Menzel, D. H.
Bibcode: 1967mopl.conf....1M
Altcode:
No abstract at ADS
Title: Panel Discussion on the Lunary Surface
Authors: Menzel, Donald H.
Bibcode: 1967phmo.conf..133M
Altcode:
No abstract at ADS
Title: The Nature of the Surface of the Moon, Illustrated in Part
by 3-D Slides Taken from Ranger Photographs
Authors: Menzel, D.
Bibcode: 1967ilpd.conf..113M
Altcode:
No abstract at ADS
Title: Selected Papers on the Transfer of Radiation (Ref. A. UNSÖLD)
Authors: Menzel, D. H.
Bibcode: 1967ZA.....66..429M
Altcode:
No abstract at ADS
Title: New Sky Patrol Program at Harvard College Observatory, Report
no. 1
Authors: Ingrao, Hector C.; Menzel, Donald
Bibcode: 1967phae.proj.2635I
Altcode:
No abstract at ADS
Title: Eclipse Over the Andes
Authors: Menzel, Donald H.
Bibcode: 1967S&T....33...11M
Altcode:
No abstract at ADS
Title: Kosmos Taschenatlas Astronomie
Authors: Menzel, Donald H.
Bibcode: 1967kta..book.....M
Altcode:
No abstract at ADS
Title: Selected papers on the transfer of radiation
Authors: Menzel, Donald Howard; Milne, Edward Arthur
Bibcode: 1966sptr.book.....M
Altcode: 1966QB817.M4.......
No abstract at ADS
Title: Planets, stars and galaxies; descriptive astronomy for
beginners
Authors: Fanning, Antony Edward; Menzel, Donald Howard
Bibcode: 1966psg..book.....F
Altcode: 1966QB44.F25.......
No abstract at ADS
Title: Detection of Hydrogen Emission Lines
n159-->n158 and
n157-->n156 iN Galactic H II Regions
Authors: Lilley, A. E.; Menzel, D. H.; Penfield, H.; Zuckerman, B.
Bibcode: 1966Natur.209..468L
Altcode:
No abstract at ADS
Title: A field guide to the stars and planets
Authors: Menzel, Donald Howard
Bibcode: 1966fgsp.book.....M
Altcode: 1966QB64.M4........
No abstract at ADS
Title: Why Take the Sun for Granted?
Authors: Menzel, Donald H.
Bibcode: 1966ossg.book...21M
Altcode:
No abstract at ADS
Title: Generalized Tables for the Calculation of Dipole Transition
Probabilities.
Authors: Shore, Bruce W.; Menzel, Donald H.
Bibcode: 1965ApJS...12..187S
Altcode:
Calculation of transition probabilities or oscillator strengths
for allowed transitions proceeds in two steps: calculation of
the dipole-moment matrix in a simple coupling scheme (usually LS
coupling) followed by transformation of this matrix to the energy
scheme. Although the oscillator strength for any transition is
proportional to the square of a matrix element, the transformation
step requires absolute values, including signs (t). Existing tables of
line and multiplet strengths omit these signs, and hence are useful
only when the atomic states are nearly LS-coupling states-often a
poor approximation. Application of the algebra of tensor operators
developed by Racah breaks the matrix-elements into a line factor, a
multiplet factor, and a transition integral. The seniority scheme of
fractional parentage solves the problems that arise when transitions
involve equivalent p and d electrons. We present formulae and tables
that permit the calculation of transitions of the type fl-I '; ; p -p
'1; p - p -'s1; -p 11 s; -p -' s2 d -d -1 1'; d"s -' si' and -d 1 1 s.
Title: What Is the Solar Corona?
Authors: Menzel, Donald H.
Bibcode: 1965wsmp.book..222M
Altcode:
No abstract at ADS
Title: The Nature of the Lunar Surface: proceedings of the 1965
IAU-NASA symposium
Authors: Hess, Wilmot N.; Menzel, Donald H.; O'Keefe, John A.
Bibcode: 1965nls..conf.....H
Altcode:
No abstract at ADS
Title: Introduction
Authors: Hess, Wilmot N.; Menzel, Donald H.; O'Keefe, John A.
Bibcode: 1965nls..confD...7H
Altcode:
No abstract at ADS
Title: Filamentary Structure in Solar Prominences.
Authors: Doherty, Lowell R.; Menzel, Donald H.
Bibcode: 1965ApJ...141..251D
Altcode:
We have computed isobaric steady-state models of prominence filamentary
structure similar to the models of Orral and Zirker. The models
have cylindrical symmetry and contain uniform longitudinal magnetic
fields. Thermal conduction transverse to the field balances the net gain
or loss of radiative energy at each point of the filament. To obtain
models with central temperatures lower than Orral and Zirker's 30000
K we have included an approximate treatment of radiative transfer in
the resonance lines of H I, He I, and He ii. We have also included
radiative losses from heavy ions and the effects of absorption
of chromospheric and coronal radiation. We find that filaments
of observable width are possible for certain values of the axial
temperature. At densities corresponding to NrT = 2 X 1013, 2 >c
10' , 2 X 1015, respectively, the axial temperature must lie near
15600 , t2100 , and 9600 K. Our models of wide filaments have broad,
almost-isothermal, central regions. The temperature rise to the corona
occurs in a thin shell. That part of the filament below 30000 K is
stable against temperature perturbations if the magnetic field has a
strength of at least 1 gauss. Above 30000 K in the shell, the conditions
for stability continue to hold if the mean free path of the neutral
particles remains small compared with the shell thickness. The shells
of our models become very thin for magnetic fields H > 1 gauss. We
cannot say, without further investigation of the heat transport and
the mechanism that heats the normal corona, whether real filaments
are entirely stable. Stability considerations alone do not set a
satisfactory upper limit on the width of filaments. We discuss the
possibility that filament size depends on a balance of the radiative
losses in the shell with the energy available to heat the corona.
Title: The Friendly Stars: How to Locate and Identify Them
Authors: Martin, Martha Evans; Menzel, Donald Howard
Bibcode: 1964frst.book.....M
Altcode: 1964QB801.M38......
No abstract at ADS
Title: Magnetohydrodynamic flow and force-free fields
Authors: Menzel, Donald H.
Bibcode: 1964ApNr....9..225M
Altcode:
No abstract at ADS
Title: Sunfish with sunspot (cartoon)
Authors: Menzel, D. H.
Bibcode: 1964susp.conf..264M
Altcode:
No abstract at ADS
Title: A field guide to the stars and planets, including the moon,
satellites, comets, and other features of the universe
Authors: Menzel, Donald Howard
Bibcode: 1964fgsp.book.....M
Altcode: 1964QB64.M4........
No abstract at ADS
Title: Sunspots, magnetic fields and the structure of the solar
atmosphere
Authors: Menzel, D. H.; Shore, B. W.
Bibcode: 1964susp.conf..226M
Altcode:
No abstract at ADS
Title: Buchbesprechung über: Stellar Interiors. (Ref. T. G. COWLING)
Authors: Menzel, D. H.; Bhatnagar, P. L.; Sen, H. K.
Bibcode: 1964ZA.....59..214M
Altcode:
No abstract at ADS
Title: Harvard College Observatory, Report.
Authors: Menzel, D. H.
Bibcode: 1963AJ.....68..631M
Altcode:
No abstract at ADS
Title: A New Program of Planetary Photography
Authors: Menzel, D. H.
Bibcode: 1963LIACo..11..115M
Altcode:
No abstract at ADS
Title: Instrumentation for Observations of Planets in the Far Infrared
Authors: Ingrao, H. C.; Menzel, D. H.
Bibcode: 1963LIACo..11..224I
Altcode:
No abstract at ADS
Title: Stellar interiors
Authors: Menzel, Donald Howard
Bibcode: 1963stin.book.....M
Altcode: 1963QB801.M45......
No abstract at ADS
Title: The Sun's Magnetic Field and the Stability of Solar Markings.
Authors: Menzel, Donald H.; Moreton, G. E.
Bibcode: 1963IAUS...16..315M
Altcode:
No abstract at ADS
Title: Magnetohydrostatic Models of the Solar Corona.
Authors: Menzel, Donald H.; Doherty, Lowell
Bibcode: 1963IAUS...16..307M
Altcode:
No abstract at ADS
Title: The Evolution of Solar Prominences.
Authors: Menzel, Donald H.; Doherty, Lowell R.
Bibcode: 1963IAUS...16..159M
Altcode:
No abstract at ADS
Title: The Atmosphere of Mars
Authors: Menzel, D. H.
Bibcode: 1963LIACo..11..411M
Altcode:
No abstract at ADS
Title: Solar Prominence Activity, 1944-1954
Authors: Menzel, Donald H.; Jones, F. Shirley
Bibcode: 1962JRASC..56..193M
Altcode:
No abstract at ADS
Title: A Hypothetical Model. (Book Reviews: Physics of the Solar
Chromosphere)
Authors: Menzel, Donald H.
Bibcode: 1962Sci...137..848T
Altcode:
No abstract at ADS
Title: Selected papers on physical processes in ionized plasmas
Authors: Menzel, D. H.
Bibcode: 1962sppp.book.....M
Altcode:
No abstract at ADS
Title: The theory of atmospheric seeing
Authors: Menzel, D. H.
Bibcode: 1962sose.conf...25M
Altcode:
No abstract at ADS
Title: Address by the representative of the U.S. National Academy
of Sciences
Authors: Menzel, Donald H.
Bibcode: 1962IAUTB..11....4M
Altcode:
No abstract at ADS
Title: Problems of Instrumentation for a Mars Probe
Authors: Menzel, Donald H.
Bibcode: 1962saa..conf..407M
Altcode:
No abstract at ADS
Title: The brightness of the sky in the vicinity of the sun
Authors: Menzel, D. H.; Sen, H. K.
Bibcode: 1962sose.conf...67M
Altcode:
No abstract at ADS
Title: Stereoscopy from Space Satellites
Authors: Menzel, Donald H.; Moreton, Gail
Bibcode: 1962saa..conf..412M
Altcode:
No abstract at ADS
Title: Study of Infrared Instrumentation for Thermal Photography of
the Moon.
Authors: Ingrao, Hector C.; Menzel, Donald H.; Burke, J. Anthony
Bibcode: 1961AJ.....66..287I
Altcode:
Successful thermal photography, for the primary purpose of temperature
measurement, depends on the value of the signal intensity at the
ground, or in a balloon or space vehicle. Computations predict the image
temperature, for an image-forming system with a single thermal detector
having a sequential readin and readout. Thermal detectors and available
single-quantum detectors with responses at wavelengths of approximately
5 p and longer are intercompared in terms of figures of merit. Infrared
sensitive image-forming systems are surveyed and discussed for lunar
thermal photography. Lateral heat conduction in the target plate of a
simultaneous readin image-forming system is analyzed to determine the
size of the minimum resolvable element. On the basis of this analysis,
we investigated the possible utility of new thermal detectors as
target plates for image-forming systems of simultaneous readin. The
potentialities of ferroelectric materials for a target plate (thin
film) of an image-forming system depend on the change in dielectric
constant as a function of temperature close to the Curie point. In
particular, measurement of the dielectric constants of thin films of
(Sr-Ba) TiO3 will enable the determination of temperatures to 10-~
0C. This corresponds to detecting an irradiance of approximately 10-10
w per resolution element for a film 100 p thick. Nonlinear phosphors,
especially zinc cadmium sulfide, are considered for thermal image
conversion. This phosphor fluoresces in the yellow and has a brightness
change of approximately 28% deg centigrade for a given ultraviolet
excitation, and phosphor temperature.
Title: A Relationship Between Flares and Loop Prominences
Authors: Menzel, Donald H.
Bibcode: 1961PASP...73..194M
Altcode:
No abstract at ADS
Title: Eclipse of the Sun of February 15, 1961 -- Soviet Solar
Eclipse Observations
Authors: Menzel, Donald H.
Bibcode: 1961S&T....21..328M
Altcode:
No abstract at ADS
Title: Eclipse of the Sun of February 15, 1961 -- Further February
Eclipse Observations
Authors: Menzel, Donald H.
Bibcode: 1961S&T....21..263M
Altcode:
No abstract at ADS
Title: Eclipse of the Sun of February 15, 1961 -- Eclipse Over the
Mediterranean
Authors: Menzel, Donald H.
Bibcode: 1961S&T....21..192M
Altcode:
No abstract at ADS
Title: Writing a technical paper
Authors: Menzel, Donald H.; Jones, Howard Mumford; Boyd, Lyle G.
Bibcode: 1961wtp..book.....M
Altcode:
No abstract at ADS
Title: Theoretical Intensity Profiles of the Solar Spectrum Near
Lyman-x
Authors: Menzel, D. H.; Doherty, L. R.
Bibcode: 1961LIACo..10..299M
Altcode: 1961LIACo..10..295M; 1961MSRSL...4..299M
No abstract at ADS
Title: The Fine Structure of Solar Prominences II
Authors: Menzel, Donald H.; Wolbach, John G.
Bibcode: 1960S&T....20..330M
Altcode:
No abstract at ADS
Title: The Fine Structure of Solar Prominences I
Authors: Menzel, Donald H.; Wolbach, John G.
Bibcode: 1960S&T....20..252M
Altcode:
No abstract at ADS
Title: Results of the Occultation of Regulus by Venus, July 7, 1959
Authors: de Vaucouleurs, G.; Menzel, D. H.
Bibcode: 1960Natur.188...28D
Altcode:
No abstract at ADS
Title: Review of Publications- Our Sun (revised edition)
Authors: Menzel, Donald H.
Bibcode: 1960JRASC..54..197M
Altcode:
No abstract at ADS
Title: The radio noise spectrum
Authors: Menzel, Donald H.
Bibcode: 1960rns..book.....M
Altcode:
No abstract at ADS
Title: On the Fine Structure of Solar Prominences.
Authors: Menzel, D. H.; Wolbach, J. G.
Bibcode: 1960AJ.....65T..54M
Altcode:
Solar prominences are not uniform clouds of luminous gas. Observations
have clearly shown them to possess filamentary structure. In "hedgerow"
prominences these filaments present the appearance of tangled skeins of
thread. In various prominences associated with sunspots the filaments
assume distinctive forms of which loops are the simplest and the
most characteristic. Large scale coronagraph records from Sacramento
Peak Observatory have disclosed a still finer structure existing in
the filaments themselves. Two types apparently exist. For example
a hazy tbread, curving gracefully from the upper corona toward the
solar surface, is not continuously luminous along its length. High
magnification shows that the filament really consists of closely spaced
hazy dashes, with the length of the dash roughly perpendicular to
the filament. In some complex prominences, the dashes on one filament
appear as continuations of those of the adjacent filament. Occasionally
the luminous pattern suggests a system of two orthogonal coordinates,
the one defined by the filaments and the second by the luminous dashes
perpendicular to the filaments. This type of pattern often appears
in the 5303 corona. The pattern and behavior suggests the occurrence
of magnetobydrodynamic shock waves, arising from some quasi- periodic
source near the base of the prominence. If the filaments run parallel to
the magnetic lines of force, the orthogonal pattern may be associated
with currents. Alternatively the pattern may well be attributed to
magnetohydrodynamic instability. The second type of fine structure
refers to the loops themselves, whose quasi-circular filament consists
of large numbers of parallel threads, whose diameters are less than
the resolving power of the instrument. Here the forms clearly suggest
the presence of electric currents along the loops, with instabilities
arising from the "pinch effect."
Title: Fundamental formulas of physics - Volume 1; Volume 2
Authors: Menzel, D. H.
Bibcode: 1960ffp..book.....M
Altcode:
No abstract at ADS
Title: Results from the Occultation of Regulus by Venus, July 7, 1959.
Authors: Menzel, Donald H.; de Vaucouleurs, G.
Bibcode: 1960AJ.....65Q.351M
Altcode:
Teams of observers from the Harvard and Smithsonian Observatories,
stationed at Madrid, Le Houga, Merate, Catania, Beirut, Shiraz,
and Bloemfontein obtained visual times of ingress and egress of
Regulus. Photoelectric light curves at ingress were recorded at Le Houga
and Bloemfontein. Analysis of the visual observations, supplemented
by published data from six European and two South African stations,
has yielded the differential geocentric coordinates of the center
of Venus with respect to Regulus on July 7,1959, at 14h24m00s U.T. a
(Regulus) -a (Venus) = - 9"1 11 ~0"013 p.e., ~(Regulus) -~(Venus) =
-0"342~0"012 p.e. The difference between observed (U.T.) and computed
(E.T.) times of mid-eclipse is - 28S.00~0S.40 (p.e.). If U.T. -
E.T. - 34s for 1959.5, aprovisional correction to the ephemeris data
is 0- C + 6S.0. The radius of the atmospheric shell corresponding
to half-intensity was 14"403~0"007 p.e., or, at unit distance,
8"500~0"005 p.e. If the optical radius is 8"41 (ephemeris value),
the corresponding altitude Zo is 65 km above the top of the cloud
layer. Analysis of the photoelectric observations by the theory of
differential refraction yielded the scale height at this altitude H(z0)
=RT/mg, and its variation with z in the range Iz-zoi ~20 km, viz.,
H(z0)=6.8~0.2 p.e. km, and (1/H) (OH/Oz) = +0.010~0.002 p.e. km-1. If
the acceleration of gravity is 860 cm sec~2, and the mean molar mass
m=42.5 (CO2 =0.90, N2 =0.09,A+ =0.01), then T(z0)=297~10p.e. 0K and
OT/Oz= +30 deg km-1. The pressure at Zo is 2.6~0. 13 p.e. dynes cm-2,
the mass of gas above zo is 3.0 X 10-~ g cm-2, the reduced thickness
1.7 cm. The observed pressure at zo is consistent with an atmospheric
model in which the pressure is 160 mb at the top of the cloud layer.
Title: A Relationship between Flares and Loop Prominences.
Authors: Menzel, Donald H.
Bibcode: 1960AJ.....65R.494M
Altcode:
Carrington's famous observation of a white-light solar flare is
reviewed. It is suggested that Carrington's observation can best be
interpreted as an extremely brilliant loop prominence, developing out of
coronal material under the action of electric currents and associated
magnetic fields, from the top downward in the manner characteristic
of loop prominences. Enhanced convection around the edges of sunspots
tends to raise the residual magnetic and electric currents there to
higher levels, where the repulsion of the magnetic fields tends to
form the current into a loop. The coronal material, caught within the
current loop, is squeezed by the well-known pinch effect to a density
so high that recombination of ions and electrons suddenly occurs,
rapidly cooling the material so that it becomes luminous in Ha and
lines of similar high excitation. If sufficient material is caught and
compressed within the loop, it will attain the brilliance of an Ha
flare; if still more is caught, sufficient to make the pinched loop
optically thick in white light, we may expect a white-light flare,
such as Carrington saw. This suggestion, that certain flares can be
identified with loop prominences, does not intend to imply that all or
even most flares are so associated. It is finally, however, suggested
that a more intensive search should be made for flares in white light,
particularly in the vicinity of large active spot groups with loop
prominence activity.
Title: Our sun
Authors: Menzel, Donald H.
Bibcode: 1959ousu.book.....M
Altcode: 1959QB521.M4.......
No abstract at ADS
Title: Variable Notebook
Authors: A. D., W.; Menzel, Donald
Bibcode: 1959phae.proj.2652W
Altcode:
No abstract at ADS
Title: Harvard College Observatory.
Authors: Menzel, D. H.
Bibcode: 1958AJ.....63..507M
Altcode:
No abstract at ADS
Title: The calculation of line profiles in a stratified atmosphere.
Authors: Doherty, L. R.; Hazen, M. L.; Menzel, D. H.
Bibcode: 1958AJ.....63..305D
Altcode:
The acceptability of a model solar atmosphere depends upon the agreement
of the observed and predicted line profiles or curves of growth, at
different angles of the emergent beam. One calculates the specific
intensity from Milne's familiar integral, in terms of a known source
function. The dependence of the result upon changes of model may be
difficult to determine and interpret physically when many variables are
present and when each integration is a relatively laborious process. We
have adopted a simplified model which allows for stratification of the
absorbing material and for a wide variety of source functions. The final
result appears in algebraic form, so that one can readily examine how
the emergent radiation varies with alteration of the parameters of the
model. The approximations that we have made are the following. I. We
have reproduced the effect of stratification by taking the ratio of
line-to-continuous absorption (Eddington's ~) as constant in a layer
between two arbitrarily chosen values of the optical depth r. We
can also obtain a simple result by taking ~ proportional to r/ (a +
r) or 2. We have assumed a constant Doppler temperature throughout
the absorbing layer. 3. We have represented the source function as
a linear combination of exponential and power terms in the optical
depth. Intensities computed under the assumptions ~tated in (I) show
that the results for variable 71 may essentially be duplicated by
a layer with 71 constant between selected optical depths. In other
words, the results are not very sensitive to the detailed form of
the stratification. From this fact we conclude that the layer model
adequately represents the effects of stratification on profiles of
absorption lines. We have also computed curves of growth and find
that a layer extending from the surface to an optical depth about 0.5
provides the best fit to the empirical curves for Fei (Bell 1951) and
Tii (Claas 1951). As might be expected, this curve also corresponds
with the theoretical Schuster-Schwarzschild curve. We anticipate
that this method will be particularly useful for source functions
that depend on depth in a complicated manner, as in the chromosphere,
or that vary over the disk, granulation and spots. This work has been
supported by the Geophysics Research Directorate, Air Force Cambridge
Research Center, under a contract with Harvard University. Bell,
B. 1951, Harvard thesis. Claas, W. 1951, Rech. Astr. Obs. Utrecht 12,
Part I. Harvard College Observatory, Cambridge, Mass.
Title: Some Advances in Solar Research
Authors: Menzel, Donald H.
Bibcode: 1957S&T....16..464M
Altcode:
No abstract at ADS
Title: Variations in the Thermodynamic State of the Chromosphere
over the Sunspot Cycle
Authors: Athay, R. G.; Menzel, D. H.; Orrall, F. Q.
Bibcode: 1957SCoA....2...35A
Altcode:
No abstract at ADS
Title: The universe in action.
Authors: Menzel, Donald Howard
Bibcode: 1957unac.book.....M
Altcode: 1957QB51.M314......
No abstract at ADS
Title: On the nature of solar activity.
Authors: Krook, Max; Menzel, Donald H.
Bibcode: 1957AJ.....62S..21K
Altcode:
The accompanying paper by Krook and Wild (1957) suggests that convective
transport of energy will be enhanced near sunspots, to make up for the
inhibition of such transport by the magnetic field of the spot. The
mechanical effects of this convection may be responsible for the
instability and activity of these regions. On this model, prominence
activity associated with spot groups should originate in the surrounding
material rather than in the spots themselves. Careful comparison
of the relative location of spots and prominences will provide an
observational check. Also correlations should be sought between
the detailed character of spot groups and the types of associated
prominences. The enhanced flux of mechanical energy involves increased
dissipation and hence above- average heating of the chromosphere and
corona near spots. These effects should appear, as in fact they do,
before a spot has surfaced. Prominences visible as dark filaments
on the disk may similarly be associated with submerged magnetic
fields. Although the main energy source for prominence activity is
probably mechanical, the actual motions will be influenced strongly by
local magnetic fields and may, in turn, also influence those fields. It
is our view that the normal convection of the quiet sun is sufficient
to produce both chromosphere and corona. The tenuous extremities of the
latter may, as Chapman has suggested, reach beyond the earth. Shock
waves, arising from the activity near spots and amplified by passage
through a medium of progressively lower density, can produce many of
the features of solar prominences. A knot ejected from an active region
will exhibit a Doppler displacement even if the matter composing it
changes constantly. The phase and amplitude cross-modulation, referred
to in the accompanying paper, permits propagation velocities in excess
of the sound velocity in the medium. Stars having a general magnetic
field sufficiently intense to inhibit atmospheric convection should
possess extended envelopes to make up for the lower efficiency of
energy transport. Although no detailed models have been worked out,
we note that stellar magnetic fields and the mechanical disturbances
associated with them may be responsible for certain varieties of stellar
variability, especially those involving expulsion of matter from the
surface and asymmetrically distended atmospheres. The research in this
paper has been supported in part by the Geophysics Research Directorate,
Air Force Cambridge Research Center, Cambridge, Mass., under contract
with Harvard University. Krook, Max and Wild, Paul. 1957, A. J. ~2,
22. Harvard College Observatory, Cambridge, Mass.
Title: On the origin of solar radio noise
Authors: Menzel, D. H.; Krook, M.
Bibcode: 1957IAUS....4..342M
Altcode:
No abstract at ADS
Title: A Model of the Chromosphere from the Helium and Continuum
Emissions.
Authors: Athay, R. G.; Menzel, D. H.
Bibcode: 1956ApJ...123..285A
Altcode:
Helium4ine emission observed in the flash spectrum at the Khartoum
eclipse is interpreted in terms of a chromospheric model. The He I
triplets have excitation temperatures of 6000 , and the singlets have
excitation temperatures of 20000 . It is demonstrated that ultraviolet
emission from the corona cannot account for the observed excitation of
helium. A model of the chromosphere is derived from the helium data
combined with the continuum data at X 3640 and X 4700. A two-column
model, with Te and fle varying from column to column along a horizontal
surface, is needed to satisfy the data. The model gives T.(h) and
fle(h) in both types of columns. The cooler columns are identified
with the spicules on the basis of the observed spicule structure on
the spectrograms.
Title: The record prominence of 10 February, 1956.
Authors: Menzel, Donald H.; Smith, Elske P.; Demastus, Howard; Ramsey,
Harry; Schnable, George; Lawrence, Robert
Bibcode: 1956AJ.....61Q.186M
Altcode:
In early February, 1956, the new solar cycle exhibited a marked increase
of activity, with the advent of several new spot groups. Prominence
Ha survey film number PFI 122 taken between 2010 and 2248 UT with
the 6-inch prominence camera on Sacramento Peak displays considerable
prominence activity in connection with a spot group near the limb. Two
bright limb flares, at position angle ~~O geographic, occurred between
2110 and 2200 UT. The film contains 632 frames, at four exposures per
minute. The beginning of the film shows what appear to be incipient
loops or half-loops with minor surge activity. Suddenly, at 2105 a
small bright spot appeared on the limb, continuing to grow in size and
brilliance for I I minutes, at which time it appeared as a luminous
bulge about 6o,ooo km in altitude. The object, without doubt, should
be classified as a limb flare. During the early stage, the velocity
of rise or expansion amounted to some 100 km per sec. The mass began
to exhibit internal filamentary structure in the form of a twisted
loop that began to expand into an active surge. In one minute the
summit of the rising mass acquired an upward velocity of 1130 km/sec,
corresponding to an acceleration 50 times greater than that of solar
gravity. A spherical mass, approximately 30,000 km in diameter,
marked the cap of the surge. This object was at first attached to
the sun by two brilliant cords, which formed a loop. These cords
broke into globules, which faded as the surge rose. The detached
spherical cap dwindled slightly in size and brilliance, until 22'
minutes later it moved out of the field of view, still retaining
the velocity of 1130 km/sec. A second, even more brilliant loop,
apparently ejected at about the same time as the first, moved outward
at a speed of about 700 km/sec. This loop, which moved more nearly
tangential to the solar limb, also broke into filaments and globules,
some of which returned sunward along highly curved trajectories. The
spot area continued to be active, ejecting a small expanding loop
at 2233. This loop broke into 2 streamers that detached themselves
and continued to rise as they faded. This active region showed other
peculiarities. Spectrograms showed Ha distorted and broadened to 6A or
more. The yellow coronal line X5694 was very intense over this area,
and remained so for several days thereafter. Even its faint companion
line, X5445, showed on spectra obtained February 12. The velocity
broke the existing speed record of 725 km/sec (Kiepenheuer 1953) by
nearly a factor of 2, and was far in excess of the escape velocity,
617 km/sec. Records from Boulder, Colorado of 460 mc/s radio noise
exhibited high-amplitude precursors with the unusually short lifetimes
of 30 seconds. The outburst accompanying the surge started abruptly
when the H-a emission region was 45,000 km above the photosphere. This
is fair agreement with the 6o,ooo km predicted by the Allen-Baumbach
model for limb sources of 460 mc/s radiation. Kiepenheuer, K. 0. 1953,
chap. in The Sun, edited by Gerard P. Kuiper (Univ. Chicago Press),
p. 412. Harvard College Observatory, Cambridge, Mass., and High Altitude
Observatory, University of Colorado, Boulder, Colo.
Title: Solar Physics
Authors: Goldberg, Leo; Menzel, Donald H.
Bibcode: 1956SCoA....1..103G
Altcode:
No abstract at ADS
Title: The E layer of the ionosphere II. Statistical Analysis
Authors: Menzel, D. H.; Wolbach, J. G.; Glazer, H.
Bibcode: 1956sei..conf..282M
Altcode:
No abstract at ADS
Title: The E layer of the ionosphere I. Physical Theory
Authors: Menzel, D. H.
Bibcode: 1956sei..conf..279M
Altcode:
No abstract at ADS
Title: The E layer of the ionosphere
Authors: Menzel, D. H.
Bibcode: 1956sei..conf....0M
Altcode:
No abstract at ADS
Title: Torsional Oscillations and Solar Magnetic Fields
Authors: Layzer, D.; Krook, M.; Menzel, D. H.
Bibcode: 1955RSPSA.233..302L
Altcode:
Torsional magneto-mechanical oscillations of finite amplitude in
an idealized non-uniformly rotating star that possesses a poloidal
magnetic field are governed, in a first approximation, by a pair of
linear wave equations. The approximation is valid if the rotational
energy and the magnetic energy are small compared with the gravitational
energy. Making various assumptions about the form of the poloidal field,
we derive numerical estimates for the period of the fundamental mode
(table 1), and discuss the results as they relate to the problem of
solar variability.
Title: The Case for H2O Clouds on Venus
Authors: Menzel, Donald H.; Whipple, Fred L.
Bibcode: 1955PASP...67..161M
Altcode:
No abstract at ADS
Title: The Thermodynamic State of the Outer Solar Atmosphere. III,
IV, and V.
Authors: Athay, S.; Matsushima, R. G.; Athay, R. N.; Thomas, R. G.;
Menzel, D. H.; Pecker, J. -C.; Thomas, R. N.
Bibcode: 1955ApJ...121..775A
Altcode:
No abstract at ADS
Title: The Thermodynamic State of the Outer Solar ATMOSPHERE.V.A.MODEL
of the Chromosphere from the Continuum Emission.
Authors: Athay, R. G.; Menzel, D. H.; Pecker, J. -C.; Thomas, R. N.
Bibcode: 1955ApJS....1..505A
Altcode:
Four semi-independent analyses of 1952 eclipse data contribute to a
determination of n and T in the solar chromosphere in the height range
from -120 km to 6000 km: (1) The intensity of the continuous emission
at X 4700 indicates that T, increases with height from about 4800 at -
65 km. (2) The emission, per cubic centimeter, in the Balmer continuum
attains a maximum near 500 km, which indicates that here the free
electrons begin to come mainly from H rather than from metals, and thus
places the limits: 5000 < T < 7000 , 4 X 1011 <n < S X 1011
at this height. (3) The intensities of the continuum at X 4700 and X
3640 require values of T as follows: 5000 at 500 km, 6100 at 1000 km,
and 6700 at 3000 kin. In the interval 1()()( 3000 kin the ionization
of H increases from about 3 to about 80 per cent. (4) Above 3000 kin
no data on the Balmer free-bound continuum exist, and an extension
of the results of 3 to greater heights requires the use of the height
gradient of the Balmer lines to replace that of the continuum. Such a
technique fixes T only within certain limits, which, at 6000 km, are:
2 X 10 < T < 1.2 X 10 . The chief uncertainty of the analysis
lies in the use of the assumption of a continuous distribution of
material in the atmosphere. The results of the analysis suggest the
validity of such assumption below about 2500 kin, and its breakdown
above about 3000 km. An estimate of optical depth in the continuum,
from the present analysis, at a height of 500 km produces a value
agreeing well with an estimate based on the analysis of the lines.
Title: Mechanisms in prominence activity
Authors: Krook, Max; Layzer, David; Menzel, Donald H.
Bibcode: 1955AJ.....60S.166K
Altcode:
H. Mechanisms in prominence activity. In a previous paper, we have
indicated that sunspots arise from volumes detached from an azimuthal
magnetic field that develops from torsional oscillations of the sun's
interior. The toroidal current systems associated with a doughnut-shaped
volume produce an internal magnetic field whose pressure tends to expand
the region against the external gas pressure. The volume is less dense
than its surroundings and, hence, rises because of magnetic buoyancy,
as noted by Parker. When the toroidal current sheets extend above the
solar surface, the internal pressures may appreciably exceed those of
the sun's atmosphere. As a consequence, we expect the sheets to collect
into loops, concentrating the matter simultaneously, through operation
of the "pinch effect." This picture of prominences in the vicinity
of sunspots is consistent with known masses of such prominences, the
gravitational forces upon the gas masses, and the known magnitude of
current densities in the neighborhood of spots. This work was supported
by the Geophysics Research Directorate, Air Force Cambridge Research
Center, through a contract with Harvard University. Harvard College
Observatory, Cambridge, Mass.
Title: The origin and evolution of sunspots.
Authors: Menzel, Donald H.; Layzer, David; Krook, Max
Bibcode: 1955AJ.....60S.171M
Altcode:
A star with differential rotation and a permanent magnetic field will in
general not be in a steady state. It performs torsional oscillations in
which during successive stages of a single cycle azimuthal fields are
first built up in one sense, decay, build up in the opposite sense,
then decay again. With even moderately small basic poloidal fields,
the lines of force may "wind round" many times and thus provide
comparatively strong azimuthal fields. Parts of these azimuthal fields
are transported to the surface and give rise to sunspots. We have,
in particular, considered an axially symmetric model for the Sun. In
a first approximation we neglect viscosity and Coriolis forces, and
consider the case of azimuthal motion of the fluid particle along
a magnetic surface (i.e., the surface of revolution generated by
rotation of a line of force about the axis of symmetry). The equations
of the problem are then rigorously linear. We have solved them by a
variational technique to determine the fundamental periods. We have
taken the lower boundary of the convective layer to be a nodal surface
for the velocity. In the present approximation, motions in different
magnetic surfaces are independent. With basic fields of the order
of 100-1000 gauss in the equatorial plane, the periods obtained are
of the order of 10 years and consistent, within the limits of our
knowledge, with the 22-year value of the spot cycle. The maximum
relative amplification of the field occurs at the nodal surface. We
are proceeding with the next approximation where inter alia coupling
between different magnetic surfaces is taken into account. The research
reported in this paper has been supported by the Geophysics Research
Directorate, Air Force Cambridge Research Center, under a contract
with Harvard University. Harvard College Observatory, Cambridge, Mass.
Title: "Turbulence", kinetic temperature, and electron temperature
in stellar atmospheres
Authors: Bhatnagar, P. L.; Krook, M.; Menzel, D. H.; Thomas, R. N.
Bibcode: 1955VA......1..296B
Altcode:
The phenomenological use of the term "astronomical turbulence"
is reviewed and earlier conclusions that the physical nature of the
phenomenon is more likely anisotropic mass-motion, or jet-prominences,
than the customary aerodynamic turbulence are restated. The primary
problem under such conditions is the relative importance of mechanical
energy-transport and momentum transport in perturbing the structure
of the atmosphere. The problem of the difference between kinetic
temperatures of the atoms and electrons is treated, and it is
concluded that the difference is negligible in those parts of the
stellar atmosphere which are in a statistically-steady state.
Title: The case for H2O clouds on Venus.
Authors: Menzel, Donald H.; Whipple, Fred L.
Bibcode: 1954AJ.....59..329M
Altcode:
There has been a tendency in recent years for astronomers to subscribe
to the theory that the clouds of Venus consist of dust rather
than H2O. The dust hypothesis, however, is inconsistent with Lyot's
polarization measures, which, on the other hand, accord well with the
behavior of light scattered by H2O clouds. Dunham has estimated that
the total amount of water vapor above the clouds of Venus does not
exceed 2 to 5 per cent of that above Mount Wilson. Recent measures of
the planet's temperature by William Sinton indicate a nearly constant
day-night value of -390C. A saturated convective atmosphere having
this temperature at the visible surface will contain appreciably
less than 2 per cent the water vapor of a saturated atmosphere at 60C
above Mount Wilson. Therefore, failure to detect water vapor in the
spectrum of Venus is at present no argument against the H,O character
of the clouds. A thick atmosphere consisting largely of CO2 could
not exist on an earth-like planet with continents protruding from
oceans of water. As Urey has shown, the CO, would be fixed in the
rocks in the form of carbonates because of its chemical reaction with
silicates in the presence of water. On the other hand, if protruding
land masses were absent, the fixation of CO, could not continue
after the formation of a thin buffer layer of carbonates. Hence, if
the surface of Venus is completely covered with water, the chemical
argument ceases to be valid. In our opinion clouds of H,O best explain
the observed characteristics of the surface of Venus. We indicate
how the working hypothesis that an ocean of water completely covers
the planet is consistent with current theories of the development of
planetary atmospheres and hydrospheres. Harvard College Observatory,
Cambridge, Mass.
Title: A model of the chromosphere from 1952 eclipse data.
Authors: Athay, R. G.; Pecker, J. C.; Thomas, R. N.; Menzel, D. H.
Bibcode: 1954AJ.....59..314A
Altcode:
An analysis of the Balmer free-bound emission at X3640 and the continuum
intensities at ~4700 was carried out using data from the slitless
spectrograms obtained by the High Altitude Observatory at Khartoum,
Sudan. The data gave intensities at X3640 and ~4700 at intervals
of approximately 100 km between 0 and 2400 km above the limb and
intensities at X4700 at many additional heights between 2400 and 48,000
km. The Balmer line data, which extended from 100 to 6400 km, was used
to supplement the free- bound data for heights between 2400 and 6000
km. Values of electron density, Ne, and kinetic temperature, Te, were
determined at heights between 0 and 6000 km. The analysis was based on
the assumption of a homogeneous chromosphere, with Ne and Te depending
upon height only. The continuum at X4700 was assumed to come from H-
emission and electron scattering of photospheric light. The results of
the analysis of the continuum data gave a chromospheric model that could
be divided into three distinct regions with the following properties:
Region I (o to 500 km). In this region Te increases from 50000K at the
photospheric limb (tangential optical depth I, radial optical depth
0.005) to 600&K at 500 km. Hydrogen begins to ionize near the top
of this region with NpHNe. This result is consistent with a marked
increase with height of the quantity NeNpTJ in the region near 500 km,
which was inferred from the Balmer free-bound and line emission. Thus
it appears that the "boundary temperature," T,nin~42000K, occurs below
a radial optical depth of 0.005. Region 2 (1000 to 3500 km). The
ionization of hydrogen increases from 5 per cent at the base to 99
per cent at the top of this region. Te increases slowly from 60000K
to > 70000 K. The low gradient of Te suggests that the external
energy supply suffices only for the ionization. Region 3 (~3500 km
up). Further ionization of hydrogen is negligible and a large rise in Te
occurs. The free-bound emission is too weak to measure in this region
and an accurate evaluation of Te is difficult. An extrapolation of the
free- bound intensities to 6000 km based on the ob- served intensities
of the Balmer lines between 2400 and 6400 km gives Te 7 X io40K. The
analysis allowed an accurate determination of Te in the region ~1500
km, and the probable errors in the data plus the errors introduced in
the analytical procedures were not likely to cause errors of more than
~3000 in Te. However, in higher regions the values of Te were quite
sensitive to the analytical procedures at~d errors of a factor 2 in Te
are possible. The eclipse spectrograms at heights above 5500 km show Ha,
and all other strong chromospheric lines that persist to these heights,
as irregular beaded structures. This irregular structure is presumably
due to spicule activity at these heights and requires the consideration
of a non-uniform chromospheric model, at least in the upper levels of
the chromosphere. A study of the Fe xi line at X7892 on the eclipse
spectrograms showed that there was strong emission in this line at
heights well below 10,000 km and suggested that the emission started
in the regions where the chromospheric lines break up into a spicule
structure. The work reported in this paper was supported by the Office
of Naval Research and carried out in close cooperation with the Naval
Research Laboratory. High A ititude Observatory, Boulder, Colo. and
Harvard College Observatory, Cambridge, Mass.
Title: Emission-Line Profiles from Expanding Envelopes.
Authors: Vainu Bappu, M. K.; Menzel, D. H.
Bibcode: 1954ApJ...119..508V
Altcode:
We have developed a method for calculating the emission4ine profiles
from an expanding envelope. The method applies to an envelope where the
emission intensity varies with latitude. Some typically illustrative
cases are considered.
Title: Lyot, Bernard
Authors: Menzel, Donald H.
Bibcode: 1952S&T....11..186M
Altcode:
No abstract at ADS
Title: Origin of the aurora borealis.
Authors: Menzel, Donald H.
Bibcode: 1952AJ.....57...20M
Altcode:
Geophysicists have generally supposed that the aurora borealis results
from the penetration of the earth's upper atmosphere by a neutral
stream of ions and electrons from the sun. The ion stream may arise
from spicule activity, the energetic surgelike prominences that occur
near the sun's poles. Future work is needed to establish the origin of
the corpuscular stream. Measures of the abundances of cosmic material
lead us to suspect that this stream from the sun consists largely of
ionized hydrogen: protons and electrons in nearly equal numbers. Focused
by solar and terrestrial magnetic fields, these ion clouds reach the
earth. In exceptional cases, as Gartlein and Meinel have shown, the
aurora borealis displays broadened and shifted lines of the Balmer
series. The physics of the emission of hydrogen gas, as developed for
studies of the planetary nebulae, applies also to the ion clouds in
the vicinity of the earth. The emission probably occurs well outside
of the earth's atmosphere, but relatively close to the earth. From the
observed brightness of the hydrogen emission we can get rough estimates
of the density of the ion cloud. Some uncertainty in this density arises
because we have no direct way of measuring the temperature. However,
for the most likely values of the temperature, which lie between I0~
and I0~ degrees K, the corresponding densities are in the range of I0~
and io8 ions per Cm3. This figure is somewhat higher than the value of
~o'/cm3 calculated by Whipple and Gossner for electron gas uniformly
distributed within the orbit of the earth. The total energy carried by
such an ion stream is about I0~ times greater than the visible energy
flux of the brighter aurora and only 20 times smaller than the flux
of solar radiation. However, the limited size of the clouds saves
the energy situation. Even so, the total energy of the bombardment
probably far exceeds the value usually quoted for the total energy of a
magnetic storm derived from the variability of the magnetic field. One
important problem relates to the relative stability of certain auroral
forms: streamers, curtains, and arcs, which may maintain an almost
unchanging pattern for times up to one hour. These luminous regions
are fixed relative to axes attached to and rotating with the earth. The
earth's motion over the interval traverses regions of space thousands
of times more extended than the original auroral streamer. To explain
this persistence of auroral forms, one may assume that currents in
the auroral levels significantly modify the earth's magnetic field,
producing funnel-like apertures through which the ion stream can
pass. This study was carried out under a contract with the Air Force
Cambridge Research Center. Harvard College Observatory, Cambridge, Mass.
Title: Variable stars in Milton field 54
Authors: Gaposchkin, Cecilia Helena Payne; Gaposchkin, Sergei; Menzel,
Donald Howard
Bibcode: 1952AnHar.115....1P
Altcode: 1952AnHar.115....1G
No abstract at ADS
Title: Aitken
Authors: Grant, Robert; Menzel, Donald H.
Bibcode: 1951S&T....11...26G
Altcode:
No abstract at ADS
Title: Some Instruments for Solar Research
Authors: Menzel, Donald H.
Bibcode: 1951S&T....10..187M
Altcode:
No abstract at ADS
Title: Transfer of Radiation. III. Reflection Effect in Eclipsing
Binaries.
Authors: Menzel, Donald H.; Sen, Hari K.
Bibcode: 1951ApJ...113..490M
Altcode:
We have applied the method described in Ap. J., 110, 1,1949 (hereafter
called "Paper I") to solve the Milne integrodifferential equation
for diffuse radiation (I) in the plane-parallel atmosphere of a
reflecting star: a I(r, ) =I(r, ) -B(r), where B(T) =51 f'I(r3 )d $
. The reflecting star is exposed to a parallel beam of radiation
of flux 7rF per unit area normal to itself and incident at an
angle p normal to the boundary of the atmosphere. We have assumed
the following expansion for B (r): B(r) =a+ +2(r) -sec where K (T)
is the exponential integral of the nth order, defined by K (r) = %
¼ dx and =1tcosP1n(tanP/2) The coefficients Aj can be evaluated from
a system of linear equations involving the C,q's tabulated in Paper
I. We have calculated the emergent intensity corresponding to the
solution of four simultaneous equations and have compared our values
with those obtained from the Chandrasekhar-Hopf formula (Ap. J., 106,
143,1947): I( ,jio) =-41F where H(M) is the solution of the functional
equation H(M) = 1+ ( )f01 H )}i#' and = CoS P The two sets of values
of the emergent intensity agree to within one part in a thousand, on
the average, and somewhat less for p = 0 , on account of a singnlarity
in the solution. The solution of more equations does not consistently
improve the agreement. We believe that for higher accuracy we need to
improve the trial function for B (r).
Title: Transfer of Radiation. II. Radiative Transfer in Absorption
Lines.
Authors: Menzel, Donald H.; Sen, Hari K.
Bibcode: 1951ApJ...113..482M
Altcode: 1951HarRe.349....1M
The equation of the formation of absorption lines in the Milne-Eddington
model of a stellar atmosphere has been solved by an extension of the
method previously described (A p. J. 110, 1,1949). The equation of
transfer in the standard case is a -1i- 'ir)di#-X(a$br) M-I (T,I#) =I
(T, ) where r is the optical depth in the total (line and continuous)
absorption, X is the ratio of the continuous to the total absorption
coefficient, and a and b are the first two coefficients of the Taylor
exparision of the Planck function in powers of r. The authors assume
an expansion of the "source function," J(r) of the form J(r) =a+b
$ce + AjKj+ (T), where m is the positive root of the equation m =
(t - X) tanli-3 m, and K (r) is the exponential integral of the nth
order, defined by Kn(r) =f1 dx. The A `s and c in J(r) are constants
which are found to be the solutions of a set of n simultaneous linear
equations in the nth order. Finally, the quantities r and R, defined
as the ratios of the emergent intensities and fluxes in the line and
continuum respectively, are obtained as functions of , p (frequency),
and the A `s. The equations have been solved for a four-term expansion
of J(r), and the values of R and r obtained have been tabulated for
the standard value of X = 0.2 and various values of the parameter x,
which is a function of the frequency p They are more accurate than the
values obtained by Chandrasekhar (Ap. J., 100, 355, 19 ) in the third
approximation b Gaussian quadrature and comparable in accuracy to the
values obtained by him (Ap. J.,106,145, 194 ) from the H(j#) function
and its moments. A special feature of the method is that it is not
restricted to the atmospheric surface but enables one to evaluate the
"source function" J(r) for any r.
Title: Magneto-hydrostatics and solar prominences.
Authors: Menzel, Donald H.
Bibcode: 1951AJ.....56Q.135M
Altcode:
The hydrodynamic equation of motion for an ionized gas, in the
presence of a magnetic field H, is dv I p Tt = - Vp + pF + - (v X
H) X H, 47r where p is the density, v the velocity, p the pressure,
and F the external force field. This is the generalized form of the
Alfve'n equation, one solution of which leads to magneto-hydrodynamic
wave motion. One can find other solutions, among them the static
case, where the magnetic forces just balance the combined effects of
gravitation and pressure gradient. The solutions suggest characteristics
of solar prominences. Further extensions of the theory to the case of
slow quasiplastic deformation indicates a possible mechanism for the
formation of prominence filaments and for the production of regions
of high temperature. I wish to thank Mrs. Martha B. Shapley for help
in carrying the final numerical integration of the equations. This
work was carried out under an Air Materiel Command Contract. Harvard
College Observatory, Cambridge, Mass.
Title: Weather conditions for the eclipse of February 25, 1952
Authors: Menzel, D. H.; Janssen, E. M.; Bell, B.
Bibcode: 1951Obs....71...81M
Altcode:
No abstract at ADS
Title: Matrices for birefringent filters.
Authors: Sen, Hari K.; Menzel, Donald H.
Bibcode: 1951AJ.....56Q.139S
Altcode:
The authors have given an alternative de elopment of the Jones matrix
calculus' for the treatment of optical systems. They have proved by
the Poincar6 sphere2 as well as by the matrix method the following
general theorem on the conditions under which a system of retardation
plates behaves rigorously as a rotator. A system of retardation
plates, oriented with respect to each other at half the face angles,
respectively, of a polyhedral angle 0, and with retardations equal to
the supplements, respectively, of the dihedral angles of 0, behaves
rigorously as a pure rotator. The rotation is equal to half the excess
of four right angles over the sum of the face angles of 0. The Jones
theorem1 th t we may produce a rotator by inserting a retardation
plate between two crossed quarter-wave plates in such a position
that its axes are at 450 with respect to the axes of the quarter-wave
plates, and that the angle of rotation will be one-half of the phase
retardation of the inserted plate, follows as a particular case of the
theorem enunciated above. The authors have also shown that the Jones
calculus (loC. Cit.) can be extended, to the order 4)2, to slightly
inclined off-axis rays (0, 4)) by replacing the phase retardation, n0,
for the ray ndrmal to the crystal surface, by n, where n0 = %(1( - a),
(I) n = no[ + 4)2k( cos2O - si$6)1, (2) - p2 k = 2( - a) p2, (3) in
which N is the wave length, and a, , are the smallest, intermediate
and greatest principal indices of refraction of a bi-axial crystal,
of thickness d, cut perpendicular to the p-axis. The formula (2)
is due to EVans4 who, however, did not consider the inclination of
the displacement vectors to the a and axes, for an off-axis ray. The
authors have shown that the formula holds good, to the order 4)2, even
under this more general circumstance. In their attempt to simplify the
Lyot birefringent filter5 of n pairs of polarizers and retardation
plates, by the general theorems on optical systems enunciated and
proved by Jones by the matrix calculus,6 the authors find that the Lyot
arrangement is the simplest possible to achieve the desired object. They
believe that the illusory nature of the simplifications implicit in
the general theorems is due to the restriction of the Jones matrices
to monochromatic light and that the removal of this restriction
will be an important step forward. Possible bases of approach
may be a perturbation method, when the incident light is sensibly
monochromatic, and the Jones time algebra, as described by N. G. Parke
III. This investigation is published under an Air Materiel Command
Contract for the establishment of a solar observatory at Sacramento
Pea , New Mexico. I.J. Opt. Soc. Amer. 31, 488, 1941. 2.Theorie
Mathematique de la Lumiere, Chap. 12, 1892. 3.J. Opt. Soc. Amer. 31,
500, 1942. 4.J. Opt. Soc. Amer. 39, 229, 1949. 5.Ann. Astroph. 7, 3',
1944. 6.J. Opt. Soc. Amer. 3', 493, 1941. 7.J. Math. Phys. 28, 131,
1949. Harvard College Observatory, Cambridge, Mass.
Title: Operational solution of the reflection effect in eclipsing
binaries.
Authors: Menzel, Donald H.; Sen, Hari K.
Bibcode: 1950AJ.....55..176M
Altcode:
We have applied the operational method described in an earlier
paper, hereafter referred to as Paper 1,1 to solve the Milne
integro-differential equation for the diffuse radiation (I) in the
plane-parallel atmosphere of a reflecting star: =I(r, -B(T), (I)
where B(r) = 21j{ i( ~ d + ` Fe-rsee . (2) The reflecting star is
exposed to a parallel beam of radiation of flux irF per unit area
normal to itself and incident at an angle normal to the boundary
of the atmosphere. We have assumed the following expansion for B(r)
= a + p"AjK5+1(T) + 4,7Fe rseeP, (3) where Ka(T) is the exponential
integral of the tb order, defined by Ka(T) = f ):rdx, (4) and I (5) I +
(cos p) ln tan - 2 The coefficients, Aj, can be evaluated from a system
of linear equations involving the Caj'S tabulated in Paper I. We have
calculated the emergent intensity corresponding to the solution of four
simultaneous equations and compared our values with those obtained from
the Chandrasekhar-Hopf formula :2 I( , o) = 41F o + H( )LI( 1), (6)
where H( ) is the solution of Ambartsumian S functional equation: H( )
= I + 2i H( )flH ($)d;', (7) and = cos . (8) The two sets of values of
the emergent intensity agree to within one part in a thousand, on the
average, and somewhat less for p = 00, on account of a singularity in
the solution, cf. (5). Solution of more equations does not consistently
improve the agreement. We believe that for higher accuracy we need
improve the trial function (3). I.Ap. J. 110, 1, 1949. 2.Ap. J. io6,
143, 1947. Harvard College Observatory, Cambridge, Mass.
Title: Origin of Sunspots
Authors: Menzel, Donald H.
Bibcode: 1950Natur.166...31M
Altcode:
ALTHOUGH astronomers have commonly believed that sunspots are
deep-seated vortices, the chief characteristics of a spot (an intense
magnetic field and a cool umbra) have never been successfully explained.
Title: Operational solution of radiative transfer in absorption lines.
Authors: Menzel, Donald H.; Sen, Hari K.
Bibcode: 1950AJ.....55...74M
Altcode:
The operational method previously described1 has been applied to solve
the equation of the formation of absorption lines in the MilneEddington
model of a solar or stellar atmosphere. The equation of transfer in
the standard case reduces to the form a arL(m i ) = Ip(T, - 2'(I -
X f ~(r, d - X(a br), (i) where T is the optical depth in the total
(line and continuous) absorption, X is the ratio of the continuous
to the total absorption coefficient, and a and b are the first two
coefficients of the Taylor expansion of the Planck function in powers of
r. The operational method gives an expansion of the "source-function"
Je(T) = 2 (I - x)j{ ~(r, d N(a br), (2) in the form J(T) = a br Ge-mr
A1Kj+2(T), (3) where m is the positive root of the equation m = (i -
X) tanh-1 m, (4) Kn(T) is the exponential integral of the nth order,
defined by Kn( ) = f1 ) ~x, (5) and c and the Ay's are constants
which are found to be the solutions of a set of n simultaneous
linear equations in the nth order. Finally, the quantities r and
R, defined as the ratios of the emergent intensities and fluxes in
the line and continuum respectively are obtained as functions of ,
p (frequency), c and the Aj's. The equations have been solved for
a four- term expansion of J(T) in (3)' and the values of R obtained
by the operational method have been tabulated for the standard value
of X = 0.2 and various values of the parameter x which is a function
of the frequency p They are more accurate than the values obtained
by Chandrasekhar2 in the third approximation by Gaussian quadrature
and comparable in accuracy to the values obtained by him1 from the
H( ) function and its moments. A special feature of the operational
method is the correct evaluation of the index of the exponential in
(3). The method also is not restricted to the atmospheric surface,
but enables one to evaluate the "source-function" J(T) in (3) for any
7. I.Ap. J. 110, 1, 1949. 2.Ap. J. 100, 355, 1944. 3.Ap. J. io6, 145,
1947. Harvard College Observatory, Cambridge, Mass.
Title: Book reviews: Our Sun
Authors: Menzel, Donald H.
Bibcode: 1950PA.....58..198M
Altcode:
No abstract at ADS
Title: Point Sources of Radio Noise
Authors: Menzel, Donald H.
Bibcode: 1950Natur.165..443M
Altcode:
ONE of the unexplained phenomena of radio-astronomy is the existence
of intense point sources of noise. These have been associated with
the galaxy because they seem to be point sources within the accuracy
of measurement, and because they have not shown pronounced parallax
or proper motion. But the assumption of galactic or stellar origin
fails to explain all the facts as understood now.
Title: Transfer of Radiation.
Authors: Menzel, Donald H.; Sen, Hari K.
Bibcode: 1949ApJ...110....1M
Altcode: 1949HarRe.330....1M
We have given below an operational method for solving the equation
of radiative transfer in a "gray" plane-parallel atmosphere. We have
assumed an expansion for the Ergiebigkeit, B('r), of the form
Title: The Physical Principles of the Quantum Theory
Authors: Menzel, Donald H.; Layzer, David
Bibcode: 1949PhilS..16..303M
Altcode: 1949HarRe.332....1M
No abstract at ADS
Title: A symbolic solution of the equation of radiative transfer.
Authors: Menzel, Donald H.
Bibcode: 1949AJ.....54Q.132M
Altcode:
The basic equation of radiative transfer, ai __ = I - B, (I) has
the symbolic solution = I - B 1 I e71" - D 1r= , (2) _______ I =
I - B - I B where I+ and I represent the specific intensities of the
outgoing and incoming beams. D is the symbolic differential operator,
is the cosine of the angle between the beam and the outward vertical,
T is the optical depth and B is the "source function." The equation
of radiative equilibrium, f11+d1i f5-dM = f)d = 2B, (3) when combined
with (2), gives the equation for B: );lI iiD4 ~1Bdii I ~ Bir=odii (4)
Setting B = a bT f$ ~iv (y) y, (5) and taking (y) = A y , (6) we obtain
a set of simultaneous linear equations for determining the coefficients
a and A in terms of b. The general solution is B = a bT A1E1+2(T),
(7) where F0(T) = f ) ~x. (8) Three terms of the summation give ample
accuracy for most purposes. Equations (7) and (2) determine the angular
distribution of the radiation intensity. Placzek has tabulated the
functions En. Harvard College Observatory, Cambridge, Mass.
Title: Earth-Sun Relationships
Authors: Menzel, Donald H.
Bibcode: 1948HarMo...7..319M
Altcode: 1948cent.symp..319M
No abstract at ADS
Title: Stellar electrodynamics.
Authors: Menzel, Donald H.
Bibcode: 1948AJ.....53Q.201M
Altcode:
An examination of Kiepenhener's theories of coronal excitation, caused
by changing sunspot fields, indicates that the mechanism provides
insufficient energy. There are, however, definite indications of
electromagnetic effects in the solar atmosphere. Salisbury and Menzel
have recently suggested, in connection with cosmic-ray phenomena,
that small-scale fluctuations may occur in various types of solar
magnetic fields. These fluctuations, if present, would result in
the emlssion of low-frequency radio waves. Horace Babcock has shown
that the star BD 1803789 possesses a rapidly reversing field, with a
period of approximately 9 days. One can readily show that this star
will radiate energy, on the above frequency, with a total power of at
least 1012 kilowatts. Harvard College Observatory, Cambridge, Mass.
Title: Audio-Frequency Radio Waves from the Sun
Authors: Menzel, Donald H.; Salisbuby, Winfield W.
Bibcode: 1948Natur.161...91M
Altcode:
THE recent discovery of solar radio noise, in the range 30-1,000
megacycles, raises the question whether lower frequencies may not
also exist. Variable magnetic fields exist on the sun and probably
in the stars as well. Small and rapid pulsations of spot fields may
well occur, even though detection of the variations, by studies of
the Zeeman effect, will prove difficult. Nevertheless, we may expect
that these changing fields will produce electromagnetic radiations the
maximum wave-lengths of which are comparable to stellar dimensions. Such
low-frequency radiation will escape from the sun in the presence of
a steady magnetic field, like those found in sunspots.
Title: The Solar Corona and Ultraviolet Radiation
Authors: Goldberg, Leo; Menzel, Donald H.
Bibcode: 1948HarMo...7..279G
Altcode: 1948cent.symp..279G
No abstract at ADS
Title: The story of the starry universe; the science of astronomy,
the size, motions, relative positions, and other phenomena of the
heavenly bodies.
Authors: Todd, David Peck; Menzel, Donald Howard
Bibcode: 1948ssus.book.....T
Altcode: 1948QB44.T64.......
No abstract at ADS
Title: Lunar rays and the dike system of the Spanish Peaks, Colorado.
Authors: Menzel, Donald H.; Damon, Ralph S.
Bibcode: 1948AJ.....53R.201M
Altcode:
A series of radial dikes, surrounding the Spanish Peaks in south
central Colorado, is suggestive of certain types of lunar-ray
formations. Although the larger rays appear to be best explained
in terms of splashes, some of the smaller rays may have resulted
from extrusive flow of magma through radial cracks. The terrestrial
analogues, because of erosion, show up as walls that attain altitudes
of 100 feet, in some cases. The paper reports results of a survey of
the Spanish Peaks area, from an American Airlines DC3 plane. Harvard
College Observatory, Cambridge, Mass.
Title: Theory of the ionosphere.
Authors: Menzel, Donald H.
Bibcode: 1948AJ.....54Q..45M
Altcode:
theory of ionospheric-layer formation, on the hypothesis of an
isothermal atmosphere. I have extended his theory to take account of
a uniform temperature gradient in the layer. The critical frequency of
a radio wave, which in turn measures the electron density follows the
law f= C(cosZ)~, where C is a complicated fact~r related to various
atomic and atmospheric parameters as well as to the intensity of solar
ionizing radiation. Z is the zenith angle of the sun. The value of
the exponent p is ~` for an isothermal atmosphere, less than ~` for
an atmosphere whose temperature increases upwards and greater than ~`
for one whose temperature decreases upwards. Application of the theory
to observations indicates increasing temperature for the E layer and
a decreasing one for the F2. Fitting the standard temperature curve at
the lower ionospheric levels, Mr. John Wolbach and I have found that a
maximum occurs between the two levels, where the temperature may reach
5oo0K. An extended theory, taking account of possibilities of electron
attachment and formation of negative ions, according to suggestions
of Massey and Bates, does not fit the observational data. However,
there are still quantitative difficulties with the more elementary
theory. Harvard College Observatory, Cambridge, Mass.
Title: Extended Sum Rules for Transition Arrays.
Authors: Menzel, Donald H.
Bibcode: 1947ApJ...105..126M
Altcode: 1947HarRe.294....1M
It is shown that the sums of multiplet strengths over a transition
array is equal t
Title: Radar and Astronomy
Authors: Menzel, Donald H.
Bibcode: 1947ASPL....5..135M
Altcode: 1947ASPL..217.....M
No abstract at ADS
Title: Continuous spectrum of the solar corona.
Authors: Menzel, Donald H.
Bibcode: 1946AJ.....52...47M
Altcode:
N}~ost of the light of the inner corona is ii~ tlie continuum;
only a fraction appears in the bright emission lines. What is
the source of this continuum? Grotrian has reported presence
of broadened Fraunhofer lines in this continuum. Pannekoek has
developed the theory of electron scattering in the corona as a source
of emission. My own records of several eclipses, obtained with a
slitless instrument, show no indication even of broadened H and K. If
electron scattering is the sotirce of the continuum, the broadening
must be at least 200 A, corresponding to an electron temperature
of almost 2 ,ooo,ooo0K. Although this figure is in keeping with
the temperature derived from excitation conditions, the occurrence
of multiply ionized iron and the breadth of the coronal emission
lines, I find one difficulty in the interpretation. All slitless
spectrograms that I have examined show that this continuous emission
appears to be closely associated with the brightness of the coronal
line X5303 (Fe xiv) and definitely not with X6374 (Fe x). In both of
the regions where coronal emissions appear, hydrogen must be almost
completely ionized. Indeed, the absence of the Balmer spectrum is
itself additional evidence of the high coronal temperatures. Most of
the electrons must come from hydrogen. It is difficult, therefore,
to see how a reduction of excitation merely from Fe xiv to Fe x can
seriously affect the electron density. Even if the corona were pure
iron, the reduction would be only 30 per cent. The close correspondence
between coronal emission and N5303 is clearly shown by spectra obtained
at the 1936 and 1932 eclipses. The latter was especially significant,
for N6374 was generally more intense than X5303 all around the limb,
except for two tiny condensations. The coronal continuum was confined
primarily to the X5303 knot. The foregoing argument is, perhaps, not
conclusive. Nevertheless, it points to the need for further work in
the continu~um, in spectral and geometric distribution. Until further
facts are available we should hesitate to accept unconditionally
the conventional explanation of electron scattering as the source
of the continuum. Unfortunately, the sky background is sufficiently
intense that the coronagraph cannot be used as a test. Studies of
this phenomenon should receive high priority at the next total solar
eclipse. Although a slit instrument has certain advantages, great
care should be taken to avoid sky fog, and to check that the light
actually does come from the eclipsed sun. Slitless corona- graphs,
even though the effective emission line has a natural width equal to
that of the coronal formatioi~, will not show absorption lines from
mere scattered sky light. Harvard College Observatory, Cambridge, Mass.
Title: The chemical composition of the planetary nebulae
Authors: Aller, Lawrence H.; Menzel, Donald H.
Bibcode: 1946PAAS...10..245A
Altcode:
No abstract at ADS
Title: An interesting prominence
Authors: Roberts, Walter O.; Menzel, D. H.
Bibcode: 1946PAAS...10S.170R
Altcode:
No abstract at ADS
Title: New Development with the Coronagraph
Authors: Menzel, Donald H.
Bibcode: 1946ASPL....5...49M
Altcode: 1946ASPL..206.....M
No abstract at ADS
Title: Electron densities and temperatures in planetary nebulae
Authors: Menzel, D. H.; Aller, L. H.
Bibcode: 1946PAAS...10...22M
Altcode:
No abstract at ADS
Title: The Fremont Pass Station of Harvard Observatory
Authors: Menzel, Donald H.; Roberts, Walter O.
Bibcode: 1946PAAS...10...62M
Altcode:
No abstract at ADS
Title: Fluorescence in planetary nebulae
Authors: Menzel, Donald H.; Aller, Lawrence H.
Bibcode: 1946PAAS...10S.141M
Altcode:
No abstract at ADS
Title: Physical Processes in Gaseous Nebulae. XVIII. The Chemical
Composition of the Planetary Nebulae.
Authors: Aller, Lawrence H.; Menzel, Donald H.
Bibcode: 1945ApJ...102..239A
Altcode:
Bowen 3nd Wyse's conclusion that the chemical composition of the
planetary nebulae is essentially the same as that of the sun is
substantiated by a more detailed treatment of the same problem in
which an attempt has been made to estimate the relative abundances
of the lighter elements. For hydrogen, helium, and carbon, which are
represented only by permitted lines of the recombination spectrum,
we have estimated mean relative abundances of 1000, 100~ and 0.6. The
abundance of hydrogen follows from the intensity of the continuous
spectrum at the limit of the BaLmer series. An estimate of the abundance
of ionized helium is provided by the observed tine intensities and
the theory given by Goldberg. The singlets are stronger than they
should be, according to Goldberg's theory; and we may interpret the
dis- crepançies between observations and theory by supposing that
collisional excitations and de-excitations of the atoms in the high 23S
and 2'S metastable levels play a role in fixing the population of the
high- energy levels. The abundances of the C iii and C iv ions have
been evaluated from the recombination lines of C n and C m with the
aid of approximate wave functions calculated by Slater's rules and
of b-factors estimated from the hydrogenic case. The 0 in abundance
in NGC 7009, as estimated from the On recombination lines, appears
to agree with that found from the green nebular lines, thus removing
the discrepancy suggested by Wyse. S We have estimated the abundances
of the other ions from their forbidden lines and, with the exception
of 0111, from approximate coffisional cross-sections. To calculate
the numbers of atoms of any kind, we must make some estimate of their
distribution among various stages of ionization. This step, which has
tc~ be made empirically, seems to introduce the greatest share of the
uncertainty in the final results. The average abundances of nitrogen,
oxygen, fluorine, neon, sulphur, chlorine, and argon are found to be
0.2, 0.25, 0.0001, 0.01, 0.036, 0.002, and 0.0015, respectively-all
on the basis of hydrogen as 1000. Compari- sons with the compositions
of the solar atmosphere and that of r Scorpii are discussed. It was
not possible to estimate the contribution of the metals. The possible
effects of stratification and of the bright-line radiation of the
central star are briefly discussed.
Title: Physical processes in gaseous nebulae
Authors: Menzel, Donald Howard
Bibcode: 1945ppgn.book.....M
Altcode:
No abstract at ADS
Title: The Wave Lengths of New Coronal Lines.
Authors: Petrie, William; Menzel, Donald H.
Bibcode: 1942ApJ....96..395P
Altcode: 1942HarRe.245....1P
The wave lengths of all coronal lines have been measured on photographs
taken with three instru- ments at the 1936 eclipse. Seven lines
obtained from three jumping-film spectra are believed to be new;
five lines measured on one ultraviolet moving-film spectrum are new;
ten lines measured on five moving- film spectra of high dispersion are
probably also new. However, it is possible that these latter features
~ originate from photographic effects of undetermined origin. Every
effort has been made to exclude the lines of the chromosphere, so that
the tabulated wave lengths may be definitely attributed to the corona
Title: Sojourn in Mexico
Authors: Menzel, Donald H.
Bibcode: 1942S&T.....1....3M
Altcode:
No abstract at ADS
Title: Biography -- The Telescope
Authors: Menzel, Donald H.
Bibcode: 1941S&T.....1....7M
Altcode:
No abstract at ADS
Title: Physical Processes in Gaseous Nebulae. XVII. Fluorescence in
High-Excitation Planetaries.
Authors: Menzel, Donald H.; Aller, Lawrence H.
Bibcode: 1941ApJ....94..436M
Altcode:
Some years ago Bowen attributed the appearance of "fractional
multiplets" of 0 iii in the spectra of high-excitation planetaries to
absorption by 0 m atoms in the 2p2 3~2 level of the X 303.80 "Lyman
alpha" radiation of helium. The subsequent cascading of these atoms
from 2p3d 3D2 of 0 m back to the ground level via the 2p3p and 2~3S
configurations are supposed to produce the observed lines. We have
attempted to put this theory on a quantitative basis by setting up the
appropriate equations of sta- tistical equilibrium for the excited
levels and predicting the relative intensities of the observed
ultraviolet lines. A comparison of observed relative intensities
with predicted relative intensities yields a con- sistency check on
the theory. The populations of the excited levels are found to be 10
4~IoI6 atoms cm3. The intensity of the radiation in the 0 m 303.80
line is from ~ to ~ times greater than that radiated by the nuclear
star, which illustrates why permitted lines of 0 rn other than those
originating by cascade from 3d~P2, are not observed. The excess is
attributed to the concentration of radiation in these lines, by cyclic
processes resulting from ionization of He+. We have also shown that
theoretically the images of the Bowen lines shoiild be about 5 per cent
larger than those of the He ii lines, which is in rough agreement with
the observational data. The paper contains tables of the relevant f's
and A's computed from approximate wave functions based on Slater's rules
Title: News from Abroad
Authors: Menzel, Donald H.
Bibcode: 1941S&T.....1...13M
Altcode:
No abstract at ADS
Title: Physical Processes in Gaseous Nebulae. XVI. The Abundance of
O III.
Authors: Menzel, Donald H.; Aller, Lawrence H.
Bibcode: 1941ApJ....94...30M
Altcode:
From the intensities of the green nebular lines the density of 0 iii
ions proves to be roughly i per cm3, corresponding to an abundance about
ten thousand times less than that of the hydrogen ions. The numbers,
nevertheless, are sufficient to produce a marked depression of the
electron temperature, through the medium of coffisional excitation. The
observed electron temperatures, given in Paper XIII, are con- sistent
with the theory developed in Paper V, modified for the effects of
collisions
Title: Artificial Eclipses of the Sun
Authors: Menzel, Donald H.
Bibcode: 1941PA.....49..191M
Altcode:
No abstract at ADS
Title: A Preface to Solar Research
Authors: Menzel, Donald H.
Bibcode: 1941SciMo..52..320M
Altcode: 1941HarRe.221....1M
No abstract at ADS
Title: Physical Processes in Gaseous Nebulae. XIII.
Authors: Menzel, Donald H.; Aller, Lawrence H.; Hebb, Malcolm H.
Bibcode: 1941ApJ....93..230M
Altcode:
The electron temperatures of several typical planetary nebulae have
been determined from the rela- tive intensities of the line X 4363
and the green nebular lines of 0 rn. The values obtained range from
about 6ooo° K to io,ooo° K, and seem to be insensitive to the
degree of excitation of the nebular spec- trum and probably also of
the temperature of the central star
Title: Physical Processes in Gaseous Nebulae. XI.
Authors: Shortley, G. H.; Aller, L. H.; Baker, J. G.; Menzel, D. H.
Bibcode: 1941ApJ....93..178S
Altcode:
The coupling of configurations p2, p3, and p4 is determined by a single
parameter x which ranges from o for LS to c~ for jj coupling. This
paper contains a tabulation of the magnetic-dipole strengths and
the coefficient of the radial integral in the electric-quadrupole
strengths for all the forbidden lines in these configurations for
all values of x. The transformation coefficients which express the
actual eigenfunctions in terms of the LS-coupling eigenfunctions are
also tabulated
Title: Physical Processes in Gaseous Nebulae. XII.
Authors: Menzel, Donald H.; Aller, Lawrence H.
Bibcode: 1941ApJ....93..195M
Altcode:
The electron densities of some typical, bright, planetary nebulae have
been estimated from the in- tensity of the continuous emission beyond
the limit of the Balmer series. The densities so obtained are of the
order of ro4 electrons/cm3 for the objects studied and are probably
somewhat lower in the fainter planetaries
Title: Physical Processes in Gaseous Nebulae. X. Collisional
Excitation of Nebulium.
Authors: Hebb, Malcolm H.; Menzel, Donald H.
Bibcode: 1940ApJ....92..408H
Altcode:
Target areas for collisional excitation of 0 iii by electron impact
are calculated by wave-mechanical methods. Coulomb wave functions are
used for the colliding electron. The resulting target areas are large,
particularly for excitation between the levels of 3P* Application to
the nebulae leads to the result that coffisional de-excitations from
3P2 predominate over the spontaneous transitions. In consequence, the
levels of 3P2 attain a high population, suited to the mechanism proposed
by Bowen: resonance ab- sorption of X 303 of He ii by the coincident
line 3P2 - 3P2 of 0 in. The figures also sug- gest, for the lower
electron densities of interstellar space, a high population of atoms
in the ground level, a result consistent with Dunham's observations
of the interstellar lines of Till
Title: Physical Processes in Gaseous Nebulae. IX. on the Excitation
of Fractional Multiplets by Electron Capture.
Authors: Shortley, George H.; Menzel, Donald H.
Bibcode: 1940ApJ....91..307S
Altcode:
Observations show that certain permitted multiplets of 0 iii and N in
are not com- pletely represented in the spectra of gaseous nebulae. Some
mechanism apparently acts to give selective excitation of certain
levels of a term, without exciting other levels. Bowen attributes the
phenomenon to resonance absorption, principally of the ultimate line
of Heu, which happens to coincide with an ultimate line of 0 iii. The
absorptions originate from the highest, instead of the lowest, levels of
the ground terms. Since these levels have mean lifetimes of the order of
several hours, Bowen's theory requires the operation of some additional
mechanism to maintain a sufficient population in the levels involved in
the fluorescence process. Another method of excitation of fractional
multiplets, direct electron capture by an ion in the ground level of
a term (e.g., 2p1j2 of o iv), is examined. The components predicted
by quantum mechanics do not, however, agree with those observed in
the nebulae. The conclusion is reached that Bowen is probably right,
although a few discrepancies stifi remain unexplained. His method ap-
parently requires inelastic electron impacts to be sufficiently frequent
to maintain ap- proximately a thermodynamic equffibrium population
of atoms in the levels of the ground term. This paper includes the
relevant quantum mechanical analysis of the rela- tive probabilities
of capture into the different levels of a configuration
Title: An Investigation of the Rowland Intensity Scale.
Authors: Menzel, Donald H.; Goldberg, Leo; Cook, Edward M.
Bibcode: 1940ApJ....91..320M
Altcode: 1940HarRe.195....1M
A new calibration of Rowland's scale of solar intensities has been
derived with the aid of the theoretical strengths of multiplets in
transition arrays. The calibration takes the form of a double-entry
table giving average values of log X0, where X0 is the optical depth at
the center of an absorption line, for each Rowland intensity from -3 to
+8 at intervals of 400 A from X 2800 to X 68oo. A total of 37 transition
arrays, representing 13 metaffic elements and 1119 lines in all, was
employed in the analysis. The present calibration is considerably less
steep than the earlier one of Russell, Adams, and Moore
Title: Artificial Total Solar Eclipses
Authors: Menzel, D. H.
Bibcode: 1940ASPL....3..301M
Altcode: 1940ASPL..139.....M
No abstract at ADS
Title: The Nature of Solar Energy
Authors: Menzel, Donald H.
Bibcode: 1940SigXQ..28....1M
Altcode: 1940HarRe.197....1M
No abstract at ADS
Title: Solar Eclipses-Old and New
Authors: Menzel, D. H.
Bibcode: 1940ASPL....3..261M
Altcode: 1940ASPL..134.....M
No abstract at ADS
Title: Physical Processes in Gaseous Nebulae. VIII. The Ultraviolet
Radiation Field and Electron Temperature of an Optically Thick Nebula.
Authors: Aller, Lawrence H.; Baker, James G.; Menzel, Donald H.
Bibcode: 1939ApJ....90..601A
Altcode:
The theory of the transfer of radiation in the Lyman continuum that was
developed in papers VI and VII of this series is applied to a numerical
example. A central star radiating as a black body at a temperature
of 80,0000 C. is assumed to illuminate a nebular shell whose optical
thickness at the Lyman series limit is 3.0. The numerical methods
of solution are discussed in detail. The redistribution of electron
velocities by collisions and free-free transitions is shown to have
considerable effect upon the char- acter of the radiation field. Near
the series limit more radiation gets through the nebula than would
otherwise be expected. The electron temperature at the inner boundary
is almost that of an optically thin nebular shell, and at the outer
boundary it approaches that of the central star
Title: Physical Processes in the Gaseous Nebulae. VII. The Transfer
of Radiation in the Lyman Continuum.
Authors: Baker, James G.; Aller, Lawrence H.; Menzel, Donald H.
Bibcode: 1939ApJ....90..271B
Altcode:
The differential equations for the transfer of radiation in the Lyman
continuum are derived. In order to take into account the varying quality
of the radiation as it passes through the nebula and also the variation
of the electron temperature, it is necessary to consider the transfer
in each element of the continuum rather than to treat the continuum as a
single level. The equation of transfer, as written down for a particular
frequency in the continuum, therefore contains a term that describes the
"interlocking" between the elements of the continuum. The application
of these equations to a numerical example is deferred to a later paper.
Title: Physical Processes in the Gaseous Nebulae. VI. The Equations
of Radiative Transfer.
Authors: Aller, Lawrence H.; Baker, James G.; Menzel, Donald H.
Bibcode: 1939ApJ....89..587A
Altcode:
The general equations of transfer for bound-bound, bound-free, and
free-free transitions for a hydrogenic nebula are derived from the
usual macroscopic equations by the identification of the emissivity and
absorptivity functions with those given in Paper I of this series. The
integration of these equations is reserved for another paper
Title: Theoretical Problems of Stellar Absorption Lines (concluded)
Authors: Menzel, Donald H.
Bibcode: 1939PA.....47..124M
Altcode:
No abstract at ADS
Title: Theoretical Problems of Stellar Absorption Lines, (continued)
Authors: Menzel, Donald H.
Bibcode: 1939PA.....47...66M
Altcode:
No abstract at ADS
Title: Some Unsolved Problems in Astrophysics
Authors: Menzel, D. H.
Bibcode: 1939ASPL....3..191M
Altcode: 1939ASPL..125.....M
No abstract at ADS
Title: Radiative transfer and Balmer decrement in the gaseous nebulae
Authors: Aller, Lawrence H.; Baker, James G.; Menzel, Donald H.
Bibcode: 1939PAAS....9R.216A
Altcode:
No abstract at ADS
Title: Radiation pressure and prominence motions
Authors: Menzel, Donald H.
Bibcode: 1939PAAS....9R.225M
Altcode:
No abstract at ADS
Title: Equivalent widths and the reversing-layer temperature
Authors: Menzel, Donald H.; Goldberg, Leo; Baker, James G.
Bibcode: 1939PAAS....9R..51M
Altcode:
No abstract at ADS
Title: Theoretical Problems of Stellar Absorption Lines
Authors: Menzel, Donald H.
Bibcode: 1939PA.....47....6M
Altcode: 1939HarRe.161....1M
No abstract at ADS
Title: Symposium on Progress in Astrophysics, American Philosophical
Society - Papers by Harvard Astronomers
Authors: Menzel, Donald H.; Payne-Gaposchkin, Cecilia; Whipple,
Fred L.; Hoffleit, Dorrit
Bibcode: 1939PAPhS..81..107M
Altcode: 1939HarRe.170....1M
No abstract at ADS
Title: Theoretical problems of nebular spectra
Authors: Menzel, D. H.
Bibcode: 1939PAAS....9..160M
Altcode:
No abstract at ADS
Title: Collision broadening of hydrogen lines
Authors: Menzel, Donald H.
Bibcode: 1939PAAS....9Q..51M
Altcode:
No abstract at ADS
Title: Physical Processes in Gaseous Nebulae. V. Electron
Temperatures.
Authors: Baker, James G.; Menzel, Donald H.; Aller, Lawrence H.
Bibcode: 1938ApJ....88..422B
Altcode:
The relation between the electron temperature of a gaseous nebula
and the temp- erature of the exciting star is derived and applied
to an optically thin nebula. The bn's have been recomputed both with
the radiation field included and as a function of the temperature of
the exciting star. The Balmer decrement proves to be steeper when the
influence of Lyman line absorption is included
Title: Physical Processes in Gaseous Nebulae. IV. The Mechanistic
and Equilibrium Treatment of Nebular Statistics.
Authors: Menzel, Donald H.; Aller, Lawrence H.; Baker, James G.
Bibcode: 1938ApJ....88..313M
Altcode:
The statistical equilibrium of nebulae has been discussed in the past
from two points of view. H. H. Plaskett employed a mechanistic argument,
where the captures in a given level are subdivided according to the
probabifity of transitions to lower levels and are followed through
successive transitions down to the ground level. Carroll criticized
Plaskett's treatment and developed equations on an equilibrium
argument. We have shown that the two points of view, when properly
applied, lead to the same result; and we have derived the necessary
equations, which will lead to a deterniina- tion of electron temperature
Title: Kramers' Absorption Law in Physical Problems
Authors: Menzel, Donald H.
Bibcode: 1938Natur.142..433M
Altcode:
IN a recent letter to NATURE1, Dr. T. L. Page reports on
an interpretation of the spectrum of hydrogen in the discharge tube
and in the planetary nebulæ. The observed data consist of measures
of the intensities, in emission, of various members of the Balmer
series and of the continuum that lies beyond the Balmer limit. Page
states: ``In the nebulæ and in the discharge it can be shown that
the recombination of protons and electrons must account for almost
the entire emission.'' He interprets the data on the basis of this
assumption. All the quanta of Balmer α, for example, he regards as
being produced by electrons that have arrived in quantum level 3 either
by direct capture in that level or by cascade from higher levels after
capture. He apparently neglects all other types of excitation, such
as reabsorption of the Lyman line radiation or collision. Failing to
find agreement between the number of captures calculated theoretically
from Kramers' well-known absorption law and the number deduced from the
observations, Page concludes that Kramers' law is in error. I should
prefer another alternative, namely, that the nebular and discharge
spectra are not entirely due to recombination.
Title: The Harvard Conference on Cepheid Variables
Authors: Gaposchkin, S.; Menzel, Donald H.; Mohr, Jenka; Norman, D.;
Schwarzschild, M.; Shapley, Harlow; Sterne, T. E.; Thorndike, S. L.;
Whipple, Fred L.
Bibcode: 1938PA.....46..378G
Altcode: 1938PA.....46..378.; 1938HarRe.148....1G
No abstract at ADS
Title: Physical Processes in Gaseous Nebulae. III. The Balmer
Decrement.
Authors: Baker, James G.; Menzel, Donald H.
Bibcode: 1938ApJ....88...52B
Altcode:
This paper contains a numerical solution of the equations derived and
formally solved in two earlier papers of the series. Various tables
of general interest, including those of functions Xn = hR/n2kT and
-[Ei(-X~)], for useful astrophysical ranges of n and Te are given. The
Balmer decrement, computed under two alternative hypotheses-A for
a nebula transparent to Lyman line radiation, and B for an opaque
nebula-is tabulated. The latter hypothesis agrees better with the
observed data. The conclusion is reached that the electron temperature,
T~, of the nebular gas cannot be effectively determined from observed
Balmer decrement data, because the decre- ment is insensitive to
temperature. In view of the extreme physical conditions that exist
in nebulae, the partition of atoms among the various excited levels
approaches surprisingly close to the thermodynamic value
Title: Investigations of the Spectra of Novae, I. — Intensities
of Bright Lines in the Spectrum of Nova Pictoris.
Authors: Payne-Gaposchkin, Cecilia; Menzel, Donald H.
Bibcode: 1938HarCi.428....1P
Altcode:
No abstract at ADS
Title: Equivalent Widths and the Temperature of the Solar Reversing
Layer
Authors: Menzel, Donald H.; Baker, James G.; Goldberg, Leo
Bibcode: 1938ApJ....87...81M
Altcode: 1938HarRe.145....1M
Allen's extensive determinations of equivalent widths of Fraunhofer
lines provide important observational material for an analysis of the
physical state of the solar atmos- phere. A comparison of the observed
intensities of absorption lines, as read from an em- pirical curve of
growth, with the theoretical strengths of lines in a transition array
makes it possible to calculate the effective excitation temperature of
the reversing layer. Tem- peratures of 4350° ± 200° and 41500 ±
50° are computed from the lines of Ti i and Fe I, respectively. A
qualitative discussion of the errors inherent in the theoretical
calculation of mul- tiplet strengths is given, and a method for
calculating the reversing-layer temperature by means of the f-file sum
rule is described. The application of this method to the lines of Ti i
yields a temperature of 4400° ± ba0. Since the sum rule is independent
of the coupling in an atom, and is therefore free of the assumptions
involved in the calculation of multiplet strengths, the value 4400° is
adopted, for purposes of discussion, as the mean excitation temperature
of the solar reversing layer. If the opacity of the solar atmosphere
varies with wave length, we should expect to find the numbers of atoms,
as derived from equivalent widths, depending upon wave length as well
as upon the temperature and excitation potential. The data for Fe in-
dicate an opacity law almost independent of wave length. These results,
however, are not definitive. Since the mean lower excitation potentials
increase systematically with wave length, opacity and temperature
effects are correlated. The data for Ti, where no systematic correlation
exists, are not inconsistent with an opacity varying as X~, whereas
theory predicts a law varying approximately as X3e-hc/XkT. An attempt
is made to rec- oncile the observations and the theoretical values
Title: Stars and planets; exploring the universe
Authors: Menzel, Donald Howard
Bibcode: 1938speu.book.....M
Altcode: 1938QB44.M4........
No abstract at ADS
Title: Physical Processes in Gaseous Nebulae. II. Theory of the
Balmer Decrement
Authors: Menzel, Donald H.; Baker, James G.
Bibcode: 1937ApJ....86...70M
Altcode:
An exact algebraic solution of the equations given in the first paper
of this series is carried out for the statistical equffibrium of an
assembly of hydrogenic atoms. The ex- citing radiation is assumed to
come oniy from beyond the limit of the Lyman series. Hence discrete
states are filled only by capture from the continuum and by cascade
from higher discrete states. The electrons are assumed to have a
Maxweffian velocity dis- tribution. The formula is given in terms of
a quantity b~, the ratio between the actual population of state n and
the population under conditions of thermodynamic equffibri- urn. An
asymptotic expression is given for b~ in the case of large quantum
number, from which it is shown that b~ approaches unity as n becomes
infinite. Numerical solu- tions are deferred until the next paper
Title: Physical Processes in Gaseous Nebulae. I.
Authors: Menzel, Donald H.
Bibcode: 1937ApJ....85..330M
Altcode:
In this paper, the first of a series dealing with the physical state
of gaseous nebulae, various fundamental formulae are derived. The
total emission and absorption of radia- tion by atomic hydrogen are
evaluated, together with the number of transitions to and from any
quantum level, discrete or continuous; The equations are thrown into
simple homogeneous form. The general equations that determine the
statistical equilibrium of the assembly and the partition of atoms
into various atomic states are developed. Solution of these equations
is deferred until a later paper
Title: Hydrogen Emission in the Chromosphere
Authors: Menzel, D. H.; Cillié, G. G.
Bibcode: 1937ApJ....85...88M
Altcode: 1937HarRe.136....1M
Intensities of the Balmer series are given up to H31 and of the
continuous spectrum beyond, as observed for the 1932 chromosphere. The
relative intensities of lines lying near together in the spectrum,
like the upper members of the Balmer series, are prob- ably close to
the truth. For lines lying far apart, like Ha and H31, the relative
intensities are subject to greater uncertainty. From the intensities
in the Balmer continuum at X 3640 and X 3500 a temperature of about
10,0000 for the free electrons in the chromosphere is deduced. From
the intensities of Ha-H31 the relative numbers of hydrogen atoms in
the vari- ous excited states can be derived. Beyond H31 the series
members merge to form a con- tinuum that grades without discontinuity
into the true Balmer continuum at A 3647.4. From the intensity of
this spectrum the population of states above the thirty-first can
be derived. These numbers are compared with those in an inclosure in
thermodynamic equilibrium, containing the same numbers of electrons
and protons and at the tem- perature of the free electrons in the
chromosphere. It is found that for states above the twentieth the
populations in the chromosphere and in the thermodynamic inclosure are
indistinguishable. For lower states the chromosphere seems to show
a relative deficiency of population. The populitions of states of
large-quantum number in a purely capture spectrum are computed, from
which figures the theoretical Balmer decrement may be calculated. It
is found that the populations are of the order of one-half of the
observed populations for the chromosphere. It appears probable that
the chromospheric hydrogen spectrum arises from line excitation as
well as from electron capture. Hydrogen emission in the chromosphere
apparently cannot be explained by the action of excess radiation in
the extreme ultraviolet, far beyond the Lyman limit
Title: The design and operation of the Harvard-M.I.T. 1936 eclipse
equipment
Authors: Menzel, Donald Howard; Boyce, Joseph C.; Hemmendinger, Henry;
Atkinson, R. d'Escourt; Brods, Wallace R.
Bibcode: 1937AnHar.105...87M
Altcode:
No abstract at ADS
Title: The design and operation of the Harvard-M.I.T. 1936 eclipse
equipment
Authors: Menzel, Donald Howard; Shapley, Harlow
Bibcode: 1937AnHar.105...88M
Altcode:
No abstract at ADS
Title: The Harvard photoelectric microdensitometer
Authors: Dimitroff, George Zakharieff; Menzel, Donald Howard;
Shapley, Harlow
Bibcode: 1937AnHar.105...99D
Altcode:
No abstract at ADS
Title: Note on Relative ƒ-VALUES for Lines of fe I
Authors: Menzel, Donald H.; Goldberg, Leo
Bibcode: 1937ApJ....85...40M
Altcode: 1937HarRe.131....1M
In connection with R. B. and A. S. King's recent intensity measurements
of Fe i absorption lines in furnace spectra, the omission of a weight
factor in reducing equiva- lent widths to relative f-values is noted. In
order to yield true f-values, the values as published must be divided
by the statistical weight of the lower level
Title: The Structure of the Atmosphere of ζ Aurigae.
Authors: Menzel, Donald H.
Bibcode: 1936HarCi.417....1M
Altcode:
No abstract at ADS
Title: The Theoretical Interpretation of Equivalent Breadths of
Absorption Lines
Authors: Menzel, Donald H.
Bibcode: 1936ApJ....84..462M
Altcode: 1936HarRe.129....1M
Formulae relating the theoretical strength of a line to its equivalent
breadth, W, are developed. Allen's empirical discovery, that W/X rather
than W must be employed when lines of various spectral regions are
to be related to one another, is explained theo- retically. By means
of the formulae referred to above, a theoretical curve of growth
is con- structed for Fe i at a temperature of 574Q0* The agreement
with Allen's empirical curve is surprisingly close when we consider
the elementary character of the assumptions and the approximations
used in obtaining the equations. The effect of a variable opacity on
the lines of neutral and ionized elements is exam- ined. It is shown
that lines of both neutral and ionized atoms should be strongest at
the frequency of maximum spectral intensity. Toward the violet or the
red the lines of neutral elements should decrease in intensity more
rapidly than those of the ionized elements
Title: Multiplet Strengths for Transitions Involving Equivalent
Electrons
Authors: Menzel, Donald H.; Goldberg, Leo
Bibcode: 1936ApJ....84....1M
Altcode: 1936HarRe.126....1M
Bacher and Goudsmit have shown that the parentage of a term arising from
a shell of equivalent electrons is expressible as a linear combination
of all the terms of the ion. When two or more terms of a kind occur in
the same configuration, however, the method gives only the sum of the
parentages of the terms involved. The resulting parentages may be used
with the well-known Kronig formulae to calculate multiplet strengths
in transition arrays where the jumping electron is equivalent to others
in oniy one of the two configurations. At the present time, the method
is applicable to all arrays involving equivalent s- and p-electrons,
and to arrays involving not more than three equivalent d-electrons. For
convenience of calculation a table containing the parentages of terms
arising from equivalent electron shells is given. The table also
lists the configurations of astro- physical interest to which these
parentages may be applied in the calculation of multi- plet strengths
Title: REVIEW: The Theory of Atomic Spectra, by E. U. Condon and
G. H. Shortley
Authors: Menzel, Donald H.
Bibcode: 1936ApJ....83Q.507M
Altcode:
No abstract at ADS
Title: The Harvard-M. I. T. Eclipse Expedition
Authors: Menzel, D. H.
Bibcode: 1936PASP...48..164M
Altcode:
No abstract at ADS
Title: Absorption coefficients and hydrogen line intensities
Authors: Menzel, D. H.; Pekeris, C. L.
Bibcode: 1936PAAS....8Q.119M
Altcode:
No abstract at ADS
Title: The interpretation of chromospheric spectra
Authors: Cillie, G. G.; Menzel, D. H.
Bibcode: 1936PAAS....8R.139C
Altcode:
No abstract at ADS
Title: The interpretation of equivalent breadths of absorption lines
Authors: Menzel, D. H.
Bibcode: 1936PAAS....8Q.218M
Altcode:
No abstract at ADS
Title: Physical and chemical state of a planetary nebula
Authors: Menzel, D. H.
Bibcode: 1936PAAS....8..146M
Altcode:
No abstract at ADS
Title: Spectrum of Nova Herculis
Authors: Gaposchkin, Cecilia Payne; Menzel, D. H.; Whipple, F. L.
Bibcode: 1936PAAS....8R.112G
Altcode:
No abstract at ADS
Title: The statistical equilibrium of a planetary nebula
Authors: Menzel, D. H.
Bibcode: 1936PAAS....8R.259M
Altcode:
No abstract at ADS
Title: Spectrum of solar corona
Authors: Boyce, J. C.; McKellar, A.; Menzel, D. H.
Bibcode: 1936PAAS....8R...6B
Altcode:
No abstract at ADS
Title: Spectrophotometry of Nova Aquilae III
Authors: Payne, C. H.; Menzel, D. H.
Bibcode: 1936PAAS....8...18P
Altcode:
No abstract at ADS
Title: Solar corona in 1932 and 1936
Authors: Menzel, D. H.; Boyce, J. C.
Bibcode: 1936PAAS....8S.259M
Altcode:
No abstract at ADS
Title: Absorption coefficients and hydrogen line intensities
Authors: Menzel, D. H.; Pekeris, C. L.
Bibcode: 1935MNRAS..96...77M
Altcode: 1935HarRe.117....1M
No abstract at ADS
Title: The Physical State of the Solar Chromosphere.
Authors: Cillié, G. G.; Menzel, D. H.
Bibcode: 1935HarCi.410....1C
Altcode:
No abstract at ADS
Title: The solar reversing layer - a question of nomenclature
Authors: Menzel, D. H.
Bibcode: 1935Obs....58...84M
Altcode:
No abstract at ADS
Title: The Classification of Stellar Spectra
Authors: Russell, N.; Payne Gaposchkin, Cecilia H.; Menzel, D. H.
Bibcode: 1935ApJ....81..107R
Altcode:
The criteria employed in the existing Draper c1assi1~ication of spectra
are detailed; the problems of more general criteria and of specific
peculiarities are considered; Struve's recent suggestions are canvassed;
and the physical prerequisites, and taxonomic prin- ciples, upon which
a definitive classification should depend, are discussed, lit is con-
cluded that such a classification should be deferred for the present
Title: Stars and planets; exploring the universe
Authors: Menzel, Donald Howard
Bibcode: 1935speu.book.....M
Altcode: 1935QB44.M4........
No abstract at ADS
Title: Nova Hercules 1934
Authors: Gaposchkin, C.; Menzel, D. H.; Whipple, F.; Shapley, Harlow
Bibcode: 1934HarAC.319....1G
Altcode:
No abstract at ADS
Title: Theories of Absorption Lines
Authors: Menzel, D. H.
Bibcode: 1934PASP...46..216M
Altcode:
No abstract at ADS
Title: Further Identifications of Nebular Lines
Authors: Boyce, J. C.; Payne-Gaposchkin, Cecilia; Menzel, D. H.
Bibcode: 1934PASP...46..213B
Altcode:
No abstract at ADS
Title: What is Light?
Authors: Menzel, Donald H.
Bibcode: 1934ASPL....2...65M
Altcode: 1934ASPL...67.....M
No abstract at ADS
Title: The Terrestrial Abundance of the Permanent Gases
Authors: Russell, Henry Norris; Menzel, Donald H.
Bibcode: 1933PNAS...19..997R
Altcode: 1933HarRe.103....1R
No abstract at ADS
Title: Neon Absorption Lines in Stellar Spectra
Authors: Menzel, Donald H.; Marshall, Roy K.
Bibcode: 1933PNAS...19..879M
Altcode: 1933HarRe..99....1M
No abstract at ADS
Title: On the Interpretation of Nova Spectra
Authors: Menzel, Donald H.; Payne, Cecilia H.
Bibcode: 1933PNAS...19..641M
Altcode: 1933HarRe..95....1M
No abstract at ADS
Title: Forbidden Lines in Astrophysical Sources
Authors: Boyce, Joseph C.; Menzel, Donald H.; Payne, Cecilia H.
Bibcode: 1933PNAS...19..581B
Altcode: 1933HarRe..93....1B
No abstract at ADS
Title: Additional identifications of forbidden nebular lines
Authors: Boyce, Joseph C.; Menzel, Donald H.; Payne, Cecilia H.
Bibcode: 1933PAAS....7Q.214B
Altcode:
No abstract at ADS
Title: The World of Atoms
Authors: Menzel, Donald H.
Bibcode: 1933ASPL....2...17M
Altcode: 1933ASPL...55.....M
No abstract at ADS
Title: A Simple Derivation of the Dissociation Formula
Authors: Menzel, Donald H.
Bibcode: 1933PNAS...19...40M
Altcode: 1933HarRe..83....1M
No abstract at ADS
Title: On the interpretation of nova spectra
Authors: Menzel, Donald Howard; Gaposchkin, Cecilia Helena Payne
Bibcode: 1933ins..book.....M
Altcode:
No abstract at ADS
Title: Physics of solar prominences
Authors: Menzel, D. H.
Bibcode: 1933PAAS....7R.179M
Altcode:
No abstract at ADS
Title: Crocker Eclipse Expedition to Fryeburg, Maine: Report on the
Jumping-Film Spectrographs
Authors: Menzel, D. H.
Bibcode: 1932PASP...44..356M
Altcode:
No abstract at ADS
Title: The Cosmic Abundance of Hydrogen Isotope H2
Authors: Menzel, D. H.
Bibcode: 1932PASP...44...41M
Altcode:
No abstract at ADS
Title: The Planetary Nebulae
Authors: Menzel, D. H.
Bibcode: 1932ASPL....1..187M
Altcode: 1932ASPL...46.....M
No abstract at ADS
Title: Opacity in Stellar Interiors
Authors: Menzel, D. H.
Bibcode: 1931PASP...43..358M
Altcode:
No abstract at ADS
Title: Physical Processes in the Gaseous Nebulae
Authors: Menzel, D. H.
Bibcode: 1931PASP...43..334M
Altcode:
No abstract at ADS
Title: Annihilation of Matter as the Source of Stellar Energy
Authors: Menzel, D. H.
Bibcode: 1931PASP...43..191M
Altcode:
No abstract at ADS
Title: Pressures at the base of the chromosphere : a critical study
of Milne's theories
Authors: Menzel, D. H.
Bibcode: 1931MNRAS..91..628M
Altcode:
No abstract at ADS
Title: The Dilution of Radiation in a Nebula
Authors: Menzel, D. H.
Bibcode: 1931PASP...43...70M
Altcode:
No abstract at ADS
Title: Turbulence as a universal characteristic of stellar atmospheres
(abstract)
Authors: Menzel, D. H.
Bibcode: 1931PA.....39Q..16M
Altcode:
No abstract at ADS
Title: Stars and planets; exploring the universe
Authors: Menzel, Donald Howard
Bibcode: 1931speu.book.....M
Altcode: 1931QB44.M4........
No abstract at ADS
Title: The structure of the solar chromosphere (abstract)
Authors: Menzel, D. H.
Bibcode: 1931PAAS....6Q.370M
Altcode:
No abstract at ADS
Title: The spectra of Jupiter and Saturn (abstract)
Authors: Menzel, Donald H.
Bibcode: 1931PAAS....6R..27M
Altcode:
No abstract at ADS
Title: The structure of the solar chromosphere (abstract)
Authors: Menzel, D. H.
Bibcode: 1931PA.....39R..15M
Altcode:
No abstract at ADS
Title: Turbulence as a universal characteristic of stellar atmospheres
(abstract)
Authors: Menzel, D. H.
Bibcode: 1931PAAS....6R.370M
Altcode:
No abstract at ADS
Title: A study of the flash spectrum
Authors: Menzel, Donald H.
Bibcode: 1931PAAS....6R.145M
Altcode:
No abstract at ADS
Title: Structure of the solar chromosphere
Authors: Menzel, Donald H.
Bibcode: 1931PAAS....6..146M
Altcode:
No abstract at ADS
Title: Temperature gradients and molecular weight in the Sun's
atmosphere
Authors: Menzel, D. H.
Bibcode: 1930Obs....53..344M
Altcode:
No abstract at ADS
Title: The Rotation of Uranus
Authors: Moore, J. H.; Menzel, D. H.
Bibcode: 1930PASP...42..330M
Altcode:
No abstract at ADS
Title: Hydrogen Abundance and the Constitution of the Giant Planets
Authors: Menzel, Donald H.
Bibcode: 1930PASP...42..228M
Altcode:
No abstract at ADS
Title: The Green Coronal Line at the Eclipse of April 28, 1930
Authors: Moore, J. H.; Menzel, D. H.
Bibcode: 1930PASP...42..182M
Altcode:
No abstract at ADS
Title: The Deviation of Stellar Atmospheres from Thermodynamic
Equilibrium
Authors: Menzel, Donald H.
Bibcode: 1930PASP...42..113M
Altcode:
No abstract at ADS
Title: Aspect of the Heavens for March and April, 1930
Authors: Menzel, Donald H.
Bibcode: 1930PASP...42...46M
Altcode:
No abstract at ADS
Title: The Identification and Cosmic Abundance of Carbon Isotopes
Authors: Menzel, Donald H.
Bibcode: 1930PASP...42...34M
Altcode:
No abstract at ADS
Title: A Study of the Solar Chromosphere Based upon Photographs of
the Flash Spectrum taken by Dr. William Wallace Campbell, Director
of the Lick Observatory, at the Total Eclipses of the Sun in 1898,
1900, 1905 and 1908
Authors: Menzel, Donald H.
Bibcode: 1930PLicO..17....1M
Altcode: 1931QB528.M4.......
No abstract at ADS
Title: Descriptions and positions of 2,829 new nebulae
Authors: Shapley, Harlow; Menzel, Donald Howard; Campbell, Leon
Bibcode: 1930AnHar..85..113S
Altcode:
No abstract at ADS
Title: The Wolf-Rayet Stars
Authors: Menzel, Donald H.
Bibcode: 1929PASP...41..344M
Altcode:
No abstract at ADS
Title: Progress of Astronomy
Authors: Menzel, D. H.
Bibcode: 1929PASP...41..224M
Altcode:
No abstract at ADS
Title: Subatomic Energy and Stellar Radiation (Conclusion)
Authors: Gerasimovič, B. P.; Menzel, D. H.
Bibcode: 1929PASP...41..145G
Altcode:
No abstract at ADS
Title: Subatomic Energy and Stellar Radiation
Authors: Gerasimovic, B. P.; Menzel, D. H.
Bibcode: 1929PASP...41...79G
Altcode:
No abstract at ADS
Title: The Nature of the Physical World (Eddington)
Authors: Menzel, D. H.
Bibcode: 1929PASP...41..107M
Altcode:
No abstract at ADS
Title: The New Rowland
Authors: Menzel, D. H.
Bibcode: 1928PASP...40..406M
Altcode:
No abstract at ADS
Title: Astronomy and Cosmogony (J. H. Jeans)
Authors: Menzel, D. H.
Bibcode: 1928PASP...40..402M
Altcode:
No abstract at ADS
Title: The Total Solar Eclipse of May 9, 1928
Authors: Menzel, D. H.
Bibcode: 1928PASP...40..411M
Altcode:
No abstract at ADS
Title: Forbidden Lines in the Flash Spectrum
Authors: Bowen, I. S.; Menzel, D. H.
Bibcode: 1928PASP...40..332B
Altcode:
No abstract at ADS
Title: Preliminary Results of Spectrographic Observations for Rotation
of Neptune
Authors: Moore, J. H.; Menzel, D. H.
Bibcode: 1928PASP...40..234M
Altcode:
No abstract at ADS
Title: The Density necessary to Produce the Nebular Spectrum
Authors: Menzel, Donald H.
Bibcode: 1928Natur.121..618M
Altcode:
IN a recent letter to NATURE (Jan. 7, p. 12) C. T. Elvey attempts to
calculate the density, ρ, of the expanding gaseous shell of a nova at
the moment when the nebular lines first appear. It is easily shown that
ρ = ρ0r02/v2t2
where ρ0 is the original density of the shell when
coincident with the stellar atmosphere, r0 its original
radius, v its velocity of expansion, and t the time elapsing between the
outburst and the appearance of the nebular lines. The above equation
involves the additional and somewhat questionable assumption that the
thickness of the expanding shell does not change. Elvey takes v from
velocity displacements on nova spectrograms. For Nova Aquilæ 3 this
is about 1700 km./sec. and t=19 days. Hence he finds, (r0
in km.). Since figures for eight additional novæ give coefficients
for ρ0r02 of the same order of
magnitude, Elvey concludes that `` the novæ originate from stars
of similar physical conditions and that there is a limiting density
above which the conditions are unfavourable for the production of the
nebular spectrum.''
Title: Structure of the solar chromosphere
Authors: Menzel, Donald H.
Bibcode: 1928PA.....36..602M
Altcode:
No abstract at ADS
Title: A study of the flash spectrum
Authors: Menzel, Donald H.
Bibcode: 1928PA.....36R.601M
Altcode:
No abstract at ADS
Title: Rare Earths in the Flash Spectrum
Authors: Menzel, D. H.
Bibcode: 1927PASP...39..359M
Altcode:
No abstract at ADS
Title: The Source of Solar Energy
Authors: Menzel, Donald H.
Bibcode: 1927Sci....65..431M
Altcode:
In an attempt to discover a reasonable explanation of the origin
and duration of the solar radiation, all possible sources of energy
are examined. The following hypotheses are reviewed and discarded,
the arguments against their validity being too well known to
necessitate a review at this place; (1) Original Heat; (2) Chemical;
(3) Gravitational, (a) Meteoric, (b) Contraction; (4) Radioactive. In
view of the failure of the above hypotheses, serious consideration is
given to the possible transmutation of matter into energy. Eddington's
massluminosity relation appears to demand such a process as the general
source of stellar radiation. It is shown that any theory which makes the
production of energy a function of temperature and pressure is subject
to severe criticisms--(a) the observed rate of energy transformation
is greater in the giant than in the hotter and denser dwarf stars;
(b) the adiabatic nature of a star would be insufficient to regulate
the generation of heat. Jeans assumes that we have, in the center of
stars, a quantity of atoms of atomic weight higher than uranium, whose
super-radioactive powers lead to decomposition into energy. The success
of the theory in accounting for the following observed facts is enough
to demand its serious consideration. 1--Life of stars of order of 1013
years 2--Better value of the stellar absorption coefficient 3--Giant
and dwarf stars 4--White dwarfs 5--Early spectral type of spectroscopic
binaries 6--Relations between visual double stars 7--Sufficiently long
time for evolution of orbits of visual binaries 8--Cepheid and Long
Period Variables (?) The main objection of Eddington to the theory
appears to be invalid.
Title: Temperatures of Mars, 1926, as derived from the Water-Cell
Transmissions
Authors: Coblentz, W. W.; Lampland, C. O.; Menzel, D. H.
Bibcode: 1927PASP...39...97C
Altcode:
No abstract at ADS
Title: Note on a Bright Meteor
Authors: Menzel, D. H.
Bibcode: 1927PASP...39...62M
Altcode:
No abstract at ADS
Title: The Accuracy of Planetary Temperatures Derived from Radiometric
Measurements
Authors: Menzel, D. H.
Bibcode: 1927PASP...39...26M
Altcode:
No abstract at ADS
Title: What About Sun-spots?
Authors: Menzel, D. H.
Bibcode: 1927ASPL....1...51M
Altcode: 1927ASPL...13.....M
No abstract at ADS
Title: The atmospheres of the outer planets (abstract)
Authors: Menzel, Donald H.
Bibcode: 1927PAAS....5R.148M
Altcode:
No abstract at ADS
Title: Planetary temperatures derived from radiation measurements
using Russell's formula (abstract)
Authors: Menzel, Donald H.; Coblentz, W. W.; Lampland, C. O.
Bibcode: 1927PAAS....5..269M
Altcode:
No abstract at ADS
Title: A spectroscopic note (abstract)
Authors: Menzel, Donald H.
Bibcode: 1927PAAS....5Q.149M
Altcode:
No abstract at ADS
Title: The spectra of Jupiter and Saturn (abstract)
Authors: Menzel, Donald H.
Bibcode: 1927PA.....35R.489M
Altcode:
No abstract at ADS
Title: The atmosphere of Mars (abstract)
Authors: Menzel, Donald H.
Bibcode: 1927PAAS....5..268M
Altcode:
No abstract at ADS
Title: Herbert Alonzo Howe, 1858-1926
Authors: Menzel, D. H.
Bibcode: 1926PASP...38..379M
Altcode:
No abstract at ADS
Title: The Present Physical Condition of Nova Aquilae (3)
Authors: Menzel, D. H.
Bibcode: 1926PASP...38..391M
Altcode:
No abstract at ADS
Title: The Planetary Nebulae
Authors: Menzel, D. H.
Bibcode: 1926PASP...38..295M
Altcode:
No abstract at ADS
Title: Planetary Temperatures Derived from Water-Cell Transmissions
Authors: Menzel, D. H.; Coblentz, W. W.; Lampland, C. O.
Bibcode: 1926ApJ....63..177M
Altcode:
In this paper the measurements of the planetary radiation transmitted
through a water cell as observed by Coblentz and Lampland at the
Lowell Observatory during the summer of 1924 are reduced by Menzel
by the method published by him in this Journal in 1923. The results
obtained seem to prove quite conclusively that the bright areas are
at a lower temperature than the dark areas, and that the equatorial
(black-body) surface temperature of Mars at perihelion rises above 0
degrees C. The true temperature, corrected for emissivity, would be
about 10 degrees higher. The temperature of the south polar cap was
-100 degrees C on August 14, gradually increasing to about -15 degrees
C on October 22, indicating that the cap is probably composed of ice
and snow. The low temperature of the east limb, which was down to -85
degrees C, is definite proof of an enormous diurnal fluctuation. Various
methods of combining the observations give concordant results. The
temperature of the moon reached 120 degrees C under perpendicular
insolation. The distribution of energy in its heat spectrum is not
consistent with a radiating surface of quartz. The temperatures of
Jupiter, Saturn, and Uranus are low, the values calculated from the
water-cell transmissions being -130 degrees C, -150 degrees C, and
-170 degrees C, respectively. There is little evidence of internal heat.
Title: The Atmosphere of Mars
Authors: Menzel, Donald H.
Bibcode: 1926ApJ....63...48M
Altcode:
No abstract at ADS
Title: Planetary temperatures derived from radiation measurements
using Russell's formula (abstract)
Authors: Menzel, Donald H.; Coblentz, W. W.; Lampland, C. O.
Bibcode: 1925PA.....33R.297M
Altcode:
No abstract at ADS
Title: The atmosphere of Mars (abstract)
Authors: Menzel, Donald H.
Bibcode: 1925PA.....33..296M
Altcode:
No abstract at ADS
Title: A Study of Line Intensities in Stellar Spectra.
Authors: Menzel, Donald H.
Bibcode: 1924HarCi.258....1M
Altcode:
No abstract at ADS
Title: The atmospheres of the outer planets (abstract)
Authors: Menzel, Donald H.
Bibcode: 1924PA.....32R.225M
Altcode:
No abstract at ADS
Title: A spectroscopic note (abstract)
Authors: Menzel, Donald H.
Bibcode: 1924PA.....32Q.226M
Altcode:
No abstract at ADS
Title: A Study of Line Intensities in Stellar Spectra.
Authors: Menzel, Donald Howard
Bibcode: 1924PhDT.........1M
Altcode:
No abstract at ADS
Title: Water-Cell Transmissions and Planetary Temperatures
Authors: Menzel, Donald H.
Bibcode: 1923ApJ....58...65M
Altcode:
No abstract at ADS
Title: Distribution of Two Thousand New Nebulae, and Distance of
the Large Magellanic Cloud
Authors: Menzel, D. H.
Bibcode: 1922PAAS....4S.374M
Altcode:
No abstract at ADS
Title: [Positions of Nebulae] discovered by D. Menzel, 2.
Authors: Menzel, Donald
Bibcode: 1922phae.proj.2308M
Altcode:
No abstract at ADS
Title: [Positions of Nebulae] discovered by D. Menzel, 1.
Authors: Menzel, Donald
Bibcode: 1922phae.proj.2307M
Altcode:
No abstract at ADS
Title: [Positions of Nebulae] discovered by D. Menzel, 3.
Authors: Menzel, Donald
Bibcode: 1922phae.proj.2309M
Altcode:
No abstract at ADS
Title: [Positions of Nebulae] discovered by D. Menzel, 4.
Authors: Menzel, Donald
Bibcode: 1922phae.proj.2310M
Altcode:
No abstract at ADS