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Author name code: leighton
ADS astronomy entries on 2022-09-14
author:"Leighton, Robert B."
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Title: VizieR Online Data Catalog: Two-Micron Sky Survey (TMSS)
(Neugebauer+ 1969)
Authors: Neugebauer, G.; Leighton, R. B.
1997yCat.2002....0N Altcode:
The catalog, giving sources of emission in the 2.2-micrometer region
for more than 5000 stars, represents a systematic survey of the
Northern Hemisphere for stars brighter than third magnitude. The
survey was carried out with a telescope at Mount Wilson, California,
having a 62-inch diameter and an f/l aluminized epoxy mirror mounted
equatorially. Radiation at an effective wavelength of 2.2 micrometers
was detected by a lead sulfide photoconductive cell cooled by liquid
nitrogen. In addition to the 2.2-micrometer detector array, radiation
at an effective wavelength of 0.84 micrometers was detected by a simple
silicon photovoltaic cell. The catalog includes right ascension and
declination (B1950.0), K and I magnitudes, number of measurements,
V magnitude, spectral types, cross identifications to the numbering
systems of the General Catalogue, the Durchmusterung catalogs, the
Bright Star Catalogue, and star names. <P />(3 data files).
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Title: Velocity Fields in the Solar Atmosphere I. Preliminary Report
Authors: Leighton, R. B.; Noyes, R. W.; Simon, G. W.
1994snft.book..382L Altcode:
No abstract at ADS
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Title: Book-Review - the Feynman Lectures on Physics - Commemorative
Issue
Authors: Feynman, R.; Leighton, R. B.; Sands, M. L.
1990Sci...249..308F Altcode:
No abstract at ADS
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Title: Interferometric C 18O Observations of DR 21(OH) and L1551
IRS 5 at gamma = 1.4 Millimeters
Authors: Padin, S.; Sargent, A. I.; Mundy, L. G.; Scoville, N. Z.;
Woody, D. P.; Leighton, R. B.; Masson, C. R.; Scott, S. L.; Seling,
T. V.; Stapelfeldt, K. R.; Terebey, S.
1989ApJ...337L..45P Altcode:
High-resolution (3 arcsec) aperture synthesis maps in the J = 2 to 1
transition of CO-18 have been obtained for the star formation regions
DR 21(OH) and L1551 IRS 5. Two compact sources, separated by 7 arcsec,
have been discovered at the centers of H2O maser activity associated
with DR 21(OH). Mass estimates from the 1.4 mm continuum and CO-18
line emission are similar to the 110 solar masses required for a
bound system with the observed 4 km/s radial velocity difference,
suggesting that a massive multiple star system is forming. The CO-18
emission from L1551 IRS 5 is extended in an elongated structure of
radius 700 AU and mass of 0.1 solar masses.
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Title: CO Emission from Evolved Stars and Proto--Planetary Nebulae
Authors: Knapp, G. R.; Sutin, B. M.; Phillips, T. G.; Ellison, B. N.;
Keene, J. B.; Leighton, R. B.; Masson, C. R.; Steiger, W.; Veidt,
B.; Young, K.
1989ApJ...336..822K Altcode:
The first observations of circumstellar CO emission from cool evolved
giant stars using the Caltech 10.4 m submillimeter telescope are
reported. New detections, some tentative, were made of 16 stars,
mostly south of -20 deg declination. Among the objects detected
are the nearby S star Pi1 Gru; the peculiar stars IRAS 15194-5115,
IRAS 19500-1709, and IRAS 23321+6545; the supergiant OH/IR star VX
Sgr; and possibly the WC10 Wolf-Rayet star CPD -56 deg 8032 - this
observation helps establish the identification of cool WC10 stars
with planetary nebula nuclei. The CO outflow velocity for VX Sgr is
about 30 Km/s, while that measured by OH maser emission is 19 Km/s,
showing that the wind velocity for VX Sgr continues to increase to
very large distances from the star. The location of the peculiar cool
stars on IRAS color-color diagrams and the detection of circumstellar
CO suggests that they are proto-planetary nebulae.
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Title: CO Emission from Centaurus A
Authors: Phillips, T. G.; Ellison, B. N.; Keene, J. B.; Leighton,
R. B.; Howard, R. J.; Masson, C. R.; Sanders, D. B.; Veidt, B.;
Young, K.
1987ApJ...322L..73P Altcode:
CO(2-1) emission has been detected along the major axis of the dust
lane in Centaurus A out to a distance of 2-arcmin from the active
nucleus. The derived radial distribution of molecular gas (H2) is
centrally peaked with a scale length of about 1.5 kpc and is similar
to that expected from a small Sc galaxy. The total H2 mass is about
a billion solar masses, comparable to the mass of atomic gas. The
molecular gas appears to be concentrated mostly at inner radii, while
the atomic gas is found predominantly at larger radii. At current linear
resolution of 1 kpc, infalling molecular gas near the nucleus could
not be detected; the kinematics of the CO emission from the nuclear
region is consistent with circular rotation. The systematic velocity of
the molecular disk is found to be 547 km/s, similar to previous values
determined for Centaurus A from H I and H II regions in the disk, and to
recent values for stars in the elliptical component, indicating that,
if it were to be considered as a disk galaxy-elliptical galaxy merger
system, Centaurus A would be well relaxed.
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Title: Aperture-Synthesis Observations of Carbon Monoxide in the
EGG Nebula
Authors: Heiligman, G. M.; Berge, G. L.; Claussen, M. J.; Leighton,
R. B.; Lo, K. Y.; Masson, C. R.; Moffet, A. T.; Phillips, T. G.;
Sargent, A. I.; Scott, S. L.; Scoville, N. Z.; Wannier, P. G.; Woody,
D. P.
1986ApJ...308..306H Altcode:
The authors have mapped the λ = 2.6 mm emission from CO in the bipolar
nebula CRL 2688 (the Egg Nebula) with 7arcsec resolution using the
Owens Valley millimeter-wave interferometer. The detected CO emission is
confined to a bright core 10arcsec×15arcsec in size; it is centered on
and has the same position angle as the optical reflection nebula. There
is a velocity gradient of 3 km s<SUP>-1</SUP>arcsec<SUP>-1</SUP> along
the major axis of the core source. The bright core source has a high
excitation temperature of ≡70K. The similarity between the CO and
optical images strongly suggests that the bright CO core is spatially
coincident with the visible reflecting dust.
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Title: Co (1-0) Maps of NGC 7027
Authors: Masson, C. R.; Cheung, K. W.; Berge, G. L.; Claussen, M. J.;
Heiligman, G. M.; Leighton, R. B.; Lo, K. Y.; Moffet, A. T.; Phillips,
T. G.; Sargent, A. I.; Scott, S. L.; Woody, D. P.
1985mlrg.proc..165M Altcode:
No abstract at ADS
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Title: High-resolution CO observations of NGC 7027.
Authors: Masson, C. R.; Cheung, K. W.; Berge, G. L.; Claussen, M. J.;
Heiligman, G. M.; Leighton, R. B.; Lo, K. Y.; Moffet, A. T.; Phillips,
T. G.; Sargent, A. I.; Scott, S. L.; Woody, D. P.
1985ApJ...292..464M Altcode:
High-resolution maps have been made of 2.6 mm CO(1-0) emission from
the planetary nebula NGC 7027 using the Owens Valley millimeter-wave
interferometer. The observations demonstrate the anisotropic structure
of the neutral cloud. The influence of this cloud on the structure of
the H II region is discussed. Anomalous, high-velocity CO emission wings
are also detected, and the relation between these and the interface
between the ionized and neutral zones is analyzed.
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Title: The Caltech millimeter wave interferometer
Authors: Masson, C. R.; Berge, G. L.; Clausen, M. J.; Heiligman,
G. M.; Leighton, R. B.
1985mswr.symp...65M Altcode:
The Caltech millimete wave interferometer is described, and some of
the first results from its use are discussed. The interferometer uses
three dishes of 10.4 m diameter and surface errors of less than 60
microns rms. The motion system of the dishes along a T-shaped track
is discussed, and the characteristics of the receivers and local
oscillators are described. A simplified diagram of the reference and
phase lock scheme is shown and discussed. The interferometer's analog
backend system, which uses filter spectrometers, is addressed. The
data sampling is discussed, including gain and phase corrections,
sideband separation, amplitude calibration, and phase calibration. The
interferometer control system is described, and some results on CO
observations of galaxies are briefly given.
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Title: Aperture synthesis observations of CO emission from the W3
molecular cloud core.
Authors: Claussen, M. J.; Berge, G. L.; Heiligman, G. M.; Leighton,
R. B.; Lo, K. Y.; Masson, C. R.; Moffet, A. T.; Phillips, T. G.;
Sargent, A. I.; Scott, S. L.; Wannier, P. G.; Woody, D. P.
1984ApJ...285L..79C Altcode:
The first aperture synthesis maps of (C-12)(O) (J = 1-0) emission from
a galactic star-forming region are presented. The line and continuum
emission from a 1 arcmin field centered on W3 IRS5 have been mapped
with the Owens Valley millimeter-wave interferometer. Although no radio
continuum emission from IRS5 was detected to a five sigma limit of 130
mJy, compact sources of high velocity red- and blue-shifted CO emission
with T(B) of about 20 K were found associated with IRS5. The estimated
mass in each wing is one solar mass, with density of about 100,000/cu
cm. The outflow is similar to other known sources with high-velocity
emission and has a short dynamic lifetime such as found in Orion. It
is suggested that the two infrared sources which comprise IRS5 are in
differing stages of evolution.
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Title: High Resolution CO Observations of NGC7027
Authors: Masson, C. R.; Cheung, K. W.; Berge, G. L.; Claussen, M. J.;
Heiligman, G. M.; Leighton, R. B.; Lo, K. Y.; Moffet, A. T.; Phillips,
T. G.; Sargent, A. I.; Scott, S. L.; Woody, D. P.
1984BAAS...16..993M Altcode:
No abstract at ADS
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Title: Aperture Synthesis CO Observations of M51
Authors: Lo, K. -Y.; Berge, G. L.; Claussen, M. J.; Heiligman, G. M.;
Keene, J.; Leighton, R. B.; Masson, C. R.; Moffet, A. T.; Phillips,
T. G.; Sargent, A. I.; Scott, S. L.; Scoville, N. Z.; Watson, D. M.;
Woody, D. P.
1984BAAS...16Q.977L Altcode: 1984BAAS...16..977L; 1984BAAS...16Z.977L
No abstract at ADS
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Title: Interferometric observations of CO in Orion : hot core and
plateau.
Authors: Masson, C. R.; Berge, G. L.; Claussen, M. J.; Heiligman,
G. M.; Leighton, R. B.; Lo, K. Y.; Moffet, A. T.; Phillips, T. G.;
Sargent, A. I.; Scott, S. L.; Wannier, P. G.; Woody, D. P.
1984ApJ...283L..37M Altcode:
One of the nearest and best studied regions of high-mass star formation
is located in the Orion molecular cloud. The present investigation is
concerned with the first observation of CO emission by interferometric
means. Attention is given to observations of CO emission from Orion
A made during the winter of 1982-1983, the obtained fringe amplitude
spectrum, the hot core, and the plateau source. The hot core is a hot
(200-250 K), dense component witlh a V(LSR) approximately 5 km/s,
which was first detected by Barrett et al. (1977) on the basis of NH3
emission. From the (C-13)O line intensity, a mass of 5 solar masses
can be computed for this region.
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Title: Aperture synthesis observations of CO emission from the
nucleus of IC342.
Authors: Lo, K. Y.; Berge, G. L.; Claussen, M. J.; Heiligman, G. M.;
Leighton, R. B.; Masson, C. R.; Moffet, A. T.; Phillips, T. G.;
Sargent, A. I.; Scott, S. L.; Wannier, P. G.; Woody, D. P.
1984ApJ...282L..59L Altcode:
The first aperture synthesis maps of 2.6 mm wavelength CO (J = 1-0)
emission from an external galaxy, IC 342. The 7-arcsec resolution maps
of the nuclear region were made with the Owens Valley Millimeter-Wave
Interferometer. They reveal that the CO source is distributed in a bar,
300 pc x more than about 1500 pc, with a velocity gradient across the
width of the bar. The observations suggest that the molecular gas in the
nucleus is moving in response to an oval gravitational potential. The
implications of an oval potential on enhanced star formation and other
activities are discussed.
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Title: Aperture-Synthesis Observations of CO in the Egg Nebula
Authors: Heiligman, G. M.; Berge, G. L.; Cheung, K. -W.; Claussen,
M. J.; Leighton, R. B.; Lo, K. -Y.; Moffet, A. T.; Phillips, T. G.;
Sargent, A. I.; Scott, S. L.; Seielstad, G. A.; Wannier, P. G.; Woody,
D. P.
1983BAAS...15..942H Altcode:
No abstract at ADS
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Title: Aperture Synthesis Maps of CO Emission from M82
Authors: Lo, K. Y.; Berge, G. L.; Claussen, M. J.; Heiligman, G. M.;
Leighton, R. B.; Masson, C. R.; Moffet, A. T.; Phillips, T. G.;
Sargent, A. I.; Scott, S. L.; Seielstad, G. A.; Wannier, P. G.; Woody,
D. P.
1983BAAS...15..915L Altcode:
No abstract at ADS
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Title: Interferometric Measurements of <SUP>12</SUP>CO Emission in
the Star-Forming Region S255
Authors: Claussen, M. J.; Berge, G. L.; Heiligman, G. M.; Leighton,
R. B.; Lo, K. -Y.; Masson, C. R.; Moffet, A. T.; Phillips, T. G.;
Sargent, A. I.; Scott, S. L.; Wannier, P. G.; Woody, D. P.
1983BAAS...15..942C Altcode:
No abstract at ADS
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Title: Observations of CO Emission from External Galaxies with the
OVRO Millimeter-wave Interferometer
Authors: Lo, K. Y.; Berge, G. L.; Claussen, M. J.; Heiligman, G.;
Leighton, R. B.; Masson, C. R.; Moffet, A. T.; Phillips, T. G.;
Sargent, A. I.; Scott, S. L.; Seielstad, G. A.; Wannier, P. G.; Woody,
D. P.
1983BAAS...15..666L Altcode:
No abstract at ADS
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Title: Interferometric Measurements of CO Emission from Orion A
Authors: Masson, C. R.; Berge, G. L.; Claussen, M. J.; Heiligman,
G. M.; Leighton, R. B.; Lo, K. -Y.; Moffet, A. T.; Phillips, T. G.;
Sargent, A. I.; Scott, S. L.; Seilestad, G. A.; Wannier, P. G.; Woody,
D. P.
1983BAAS...15..639M Altcode:
No abstract at ADS
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Title: High Spatial Resolution Observations of <SUP>12</SUP>CO in
Molecular Cloud Cores
Authors: Claussen, M. J.; Berge, G. L.; Heiligman, G. M.; Leighton,
R. B.; Lo, K. -Y.; Masson, C. R.; Moffet, A. T.; Phillips, T. G.;
Sargent, A. I.; Scott, S. L.; Seilestad, G. A.; Wannier, P. G.; Woody,
D. P.
1983BAAS...15..639C Altcode:
No abstract at ADS
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Title: Mass loss from evolved stars. I. Observations of 17 stars in
the CO(2-1) line.
Authors: Knapp, G. R.; Phillips, T. G.; Leighton, R. B.; Lo, K. Y.;
Wannier, P. G.; Wootten, H. A.; Huggins, P. J.
1982ApJ...252..616K Altcode:
Observations of 29 evolved stars in the CO J = 2-1 line are
reported. For 17 of the stars, CO emission from circumstellar molecular
gas is detected. Four of the stars (R Leo, R LMi, RX Boo, and Alpha
Ori) are detected as CO sources for the first time. The data are
analyzed using a simple approximate model of the molecular emission
from a stellar molecular envelope, and values of the mass-loss rate
are found. Most of the stellar envelopes are found to be optically
thick in the CO lines. The mass loss rates for the carbon stars are
seen as too large in many cases to be driven by radiation pressure on
dust in the envelope. For the Mira variables and possibly for the S
stars, the fraction of the stellar photon momentum corresponding to
the observed mass loss rate is found to correlate with the amount of
dust in the envelope.
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Title: Cosmic-Rays - a Scientific Cornucopia
Authors: Leighton, R.
1982EnSci..46...19L Altcode: 1982eas..conf...19L
No abstract at ADS
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Title: Detection of the CO J = 2-1 line in M82 and IC 342
Authors: Knapp, G. R.; Leighton, R. B.; Wannier, P. G.; Phillips,
T. G.; Huggins, P. J.
1980ApJ...240...60K Altcode:
A search has been conducted for the CO(2-1) line at 230 GHz in four
galaxies and it has been detected in two, IC 342 and M82. Comparison
with data for the CO(1-0) line in these galaxies shows that the
molecular gas in IC 342 appears to be optically thick; that in M82,
however, is of low optical depth. A comparison of the gas and stellar
content of the central region of M82 suggests that much of the current
star formation is taking place as high-mass stars.
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Title: Observations of circumstellar clouds
Authors: Wannier, P. G.; Redman, R. O.; Leighton, R. B.; Knapp, G. R.;
Phillips, T. G.; Huggins, P. J.
1980IAUS...87..487W Altcode:
Results of J = 2-1 CO observations in circumstellar clouds of IRC+10216
and Mira (o Ceti) are reported. A very large rate of mass loss is
suggested by the CO emission over a diameter of 6 arcmin (approximately
0.5 pc) of the former. The latter shows a high CO excitation temperature
and a small CO opacity. It is suggested that this gas heating is a
result of the orbital motion of the central star. The observations
discussed provide high spatial resolution (approximately 25 arcsec)
of a line CO (J = 2-1) which traces out the most extended molecular gas.
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Title: High-resolution observations of CO in IRC +10216 and three
related objects.
Authors: Wannier, P. G.; Leighton, R. B.; Knapp, G. R.; Redman, R. O.;
Phillips, T. G.; Huggins, P. J.
1979ApJ...230..149W Altcode:
The 10-m telescope at the Caltech Owens Valley Radio Observatory has
been used to make 26-arcsec resolution observations at 230 GHz. The
circumstellar cloud in IRC + 10216 was fully resolved and mapped using
the J = 2-1 line of CO; the emission is found to be centrally peaked
and circularly symmetric. The extended emission may imply that the
stellar mass loss was more rapid in the past. Also observed were three
other circumstellar sources (CIT 6, CRL 2688, and NGC 7027). In each
case the CO(2-1) line intensity is unexpectedly high.
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Title: A 10-Meter Telescope for Millimeter and Sub-Millimeter
Astronomy
Authors: Leighton, Robert B.
1977nsf..rept.....L Altcode:
The design and construction of a prototype 10.4 meter, f/0.4 telescope
intended for millimeter- and submillimeter-wave astronomy is described,
with particular emphasis on design features, fabrication techniques,
and error sources. The surface accuracy attained on a prototype dish
was about 50 μm rms; on the first of four "production" dishes, about
25 μm rms; the goal for at least one of the four dishes is to be 10
μm rms or less. The reflecting surface is sheet aluminum cemented to
accurately machined honeycomb panels. The 84 demountable panels are
supported on a tubular steel- framework which is itself disassemblable
into a few easily transportable pieces. A notable feature is that the
dish may be disassembled and reassembled without significant loss of
accuracy and without need for later readjustment, although the means
for readjustment are provided. The mount is of the altazimuth fork
type and has an initial absolute pointing accuracy of 6 - 10" and a
tracking accuracy of 1 - 2" in the absence of strong wind gusts, which
degrade the tracking accuracy somewhat. The telescope, operated in an
f/4.2 cassegrain mode at 230 GHz, has a system effeciency greater than
50 percent. Three such telescopes are to be installed at Owens Valley
Radio Observatory and used as a millimeter-wave aperture synthesis
radio interferometer. A fourth telescope, of especially high dish
accuracy, is to be built and tested at OVRO and later moved to a high,
dry mountain site for submillimeter infrared and radio astronomy.
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Title: Millimeter-wave antenna design
Authors: Leighton, R. B.
1977cait.rept.....L Altcode:
Problems and opportunities are discussed for adapting certain design
features and construction techniques, developed for producing high
accuracy ground based radio dishes, to producing milimeter wave dishes
for space use. Specifically considered is a foldable telescope of 24 m
aperture and 9.6 m focal length, composed of 37 rigid hexagonal panels,
which will fit within the 4.5 m diameter x 18 m long payload limits of
space shuttle. As here conceived, the telescope would be a free flyer
with its own power and pointing systems. Some of the structural design
features and construction procedures are considered.
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Title: Prototype 10-meter radio telescope antenna and mount design
Authors: Leighton, R. B.
1976cait.rept.....L Altcode:
A prototype radio antenna of 10.4 meters diameter and 0.41 meter focal
length, intended for use at the shortest radio wavelengths transmitted
by the atmosphere, was successfully completed. The surface accuracy is
at least four times better than that of any existing antenna in this
size class: 50 micrometer rms. A prototype mount is being constructed
and will be ready by early 1976. The development of an improved antenna
of identical size, but heavier weight has been continued.
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Title: Mariner 6 and 7 picture analysis
Authors: Leighton, R. B.
1975cait.reptQ....L Altcode:
Analysis of Mariner 6 and 7 far-encounter (FE) pictures is
discussed. The purpose of the studies was to devise ways to combine
digital data from the full set of FE pictures so as to improve surface
resolution, distinguish clouds and haze patches from permanent surface
topographic markings, deduce improved values for radius, oblateness,
and spin-axis orientation, and produce a composite photographic map of
Mars. Attempts to measure and correct camera distortions, locate each
image in the frame, and convert image coordinates to martian surface
coordinates were highly successful; residual uncertainties in location
were considerably less than one pixel. However, analysis of the data to
improve the radius, figure, and axial tilt and to produce a composite
map was curtailed because of the superior data provided by Mariner
9. The data, programs, and intermediate results are still available
(1976), and the project could be resumed with little difficulty.
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Title: Design and construction of prototype radio antenna for shortest
radio wavelengths
Authors: Leighton, R. B.
1975cait.reptR....L Altcode:
A paraboloid radio antenna of 10.4 meters diameter, 0.41 meter focal
length was constructed and its successful completion is described. The
surface accuracy of the antenna is at least four times better than any
existing antenna in its class size (50 micrometers rms). Antenna design
specifications (i.e., for mounting, drive motors, honeycomb structures)
are discussed and engineering drawings and photographs of antenna
components are shown. The antenna will be used for millimeter-wave
interferometry and sub-millimeter wave radiometry over a full frequency
range (up to approximately 860 GHz). The antenna will also be moveable
(for interferometric use) between reinforced concrete pads by rail. The
effects of the weather and gravity on antenna performance are briefly
discussed.
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Title: The Richtmyer Memorial Lecture: A Physicist Looks at Mars
Authors: Leighton, Robert B.
1972AmJPh..40.1569L Altcode:
Response of the Richtmyer Memorial Lecturer to the American Association
of Physics Teachers, 1 February 1972.
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Title: Geological Framework of the South Polar Region of Mars (A 4. 4)
Authors: Murray, Bruce C.; Soderblom, Laurence A.; Cutts, James A.;
Sharp, Robert P.; Milton, Daniel J.; Leighton, Robert B.
1972Icar...17..328M Altcode:
The first 4 months of Mariner 9 photography of the south polar region
are discussed. Three major geological units have been recognized,
separated by erosional unconformities. From oldest to youngest they
are: cratered terrain, pitted plains, and laminated terrain. The
latter unit is unique in occurrence to the polar region, volatiles
are probably involved in its origin, and may still be present within
the laminated terrain as layered ice. The residual south polar cap
has been observed to survive the disappearance of the thin annual CO
<SUB>2</SUB> frost deposit and to last virtually unchanged in outline
through the southern summer. That exposed deposit is inferred to be
composed of water-ice. The residual cap appears to lie at the apex
of an unusual quasi-circular structure composed of laminated terrain;
a similar structure also appears to exist near the north pole.
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Title: Large-Scale Photospheric Magnetic Field: The Diffusion of
Active Region Fields
Authors: Schatten, Kenneth H.; Leighton, Robert B.; Howard, Robert;
Wilcox, John M.
1972SoPh...26..283S Altcode:
The large-scale photospheric magnetic field has been computed by
allowing observed active region fields to diffuse and to be sheared
by differential rotation in accordance with the Leighton (1969)
magnetokinematic model of the solar cycle. The differential rotation
of the computed field patterns as determined by autocorrelation curves
is similar to that of the observed photospheric field, and poleward of
20° latitude both are significantly different from the differential
rotation of the long-lived sunspots (Newton and Nunn, 1951) used as
an input into the computations.
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Title: Mariner 9 Mars Television Experiment
Authors: Masursky, H.; Batson, R. M.; Carr, M. H.; McCauley, J. F.;
Milton, D. J.; Soderblom, L. A.; Wildey, R. L.; Wilhelms, D. E.;
Lederberg, J.; Levinthal, E.; de Vaucouleurs, G.; Briggs, G. A.;
Young, A. T.; Smith, B. A.; Cutts, J. A.; Leighton, R. B.; Murray,
B. C.; Sharp, R. P.; Hartmann, W. K.; Leovy, C. B.; Davies, M. E.;
Sagan, C.; Veverka, J.; Shipley, E. N.; Pollack, J. B.
1972BAAS....4..356M Altcode:
No abstract at ADS
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Title: Mariner 9 Television Reconnaissance of Mars and Its Satellites:
Preliminary Results
Authors: Masursky, Harold; Batson, R. M.; McCauley, J. F.; Soderblom,
L. A.; Wildey, R. L.; Carr, M. H.; Milton, D. J.; Wilhelms, D. E.;
Smith, B. A.; Kirby, T. B.; Robinson, J. C.; Leovy, C. B.; Briggs,
G. A.; Duxbury, T. C.; Acton, C. H., Jr.; Murray, B. C.; Cutts, J. A.;
Sharp, R. P.; Smith, Susan; Leighton, R. B.; Sagan, C.; Veverka, J.;
Noland, M.; Lederberg, J.; Levinthal, E.; Pollack, J. B.; Moore, J. T.,
Jr.; Hartmann, W. K.; Shipley, E. N.; de Vaucouleurs, G.; Davies, M. E.
1972Sci...175..294M Altcode:
At orbit insertion on 14 November 1971 the Martian surface was largely
obscured by a dust haze with an extinction optical depth that ranged
from near unity in the south polar region to probably greater than 2
over most of the planet. The only features clearly visible were the
south polar cap, one dark spot in Nix Olympica, and three dark spots in
the Tharsis region. During the third week the atmosphere began to clear
and surface visibility improved, but contrasts remained a fraction of
their normal value. Each of the dark spots that apparently protrude
through most of the dust-filled atmosphere has a crater or crater
complex in its center. The craters are rimless and have featureless
floors that, in the crater complexes, are at different levels. The
largest crater within the southernmost spot is approximately 100
kilometers wide. The craters apparently were formed by subsidence and
resemble terrestrial calderas. The south polar cap has a regular margin,
suggsting very flat topography. Two craters outside the cap have frost
on their floors; an apparent crater rim within the cap is frost free,
indicating preferential loss of frost from elevated ground. If this
is so then the curvilinear streaks, which were frost covered in
1969 and are now clear of frost, may be low-relie ridges. Closeup
pictures of Phobos and Deimos show that Phobos is about 25 ± 5
by 21 ± 1 kilometers and Deimos is about 13.5 ± 2 by 12.0 ± 0.5
kilometers. Both have irregular shapes and are highly cratered, with
some craters showing raised rims. The satellites are dark objects with
geometric albedos of 0.05.
---------------------------------------------------------
Title: The surface of Mars. 4. South polar cap.
Authors: Sharp, R. P.; Murray, B. C.; Leighton, R. B.; Soderblom,
L. A.; Cutts, J. A.
1971JGR....76..357S Altcode:
The south polar cap of Mars occupies a region of cratered
terrain. Immediately outside the shrinking cap craters appear no
more modified than those in areas farther north that are not annually
frost covered. Craters showing through the frost mantle are locally as
abundant as elsewhere on Mars. Only in a central region close to the
pole are craters sparse. Both far- and near-encounter views reveal a
highly irregular pole-cap edge. Photos of the same sector taken six
days apart are near duplicates, suggesting that the irregularity is
primarily ground controlled. No evidence of the classical polar collar
is seen. Within the marginal zone, frost is preserved largely in crater
bottoms and on slopes inclined away from the sun. Preferential retention
in low spots supports the earlier suggestion that the Mountains of
Mitchel may actually be depressions. An argument based on insolation as
the prime factor in frost wastage and the narrow width of the marginal
zone suggests that slopes of topographic features therein are mostly
gentle, on the order of a few degrees. The frost cover of the pole-cap
interior may range widely in thickness, obscuring parts of some craters
and seemingly enhancing topographic visibility elsewhere, possibly
through variations in thickness and reflectivity. Unusually bright
areas on the cap surface, and differences in luminance between bright
rims and the more somber floors of craters and other depressions,
may be due in large part to differences in related frost textures
and to the local history of evaporation and sublimation. Irregularly
angular depressions within the polecap frost termed `etch pits' may
be the product of differential ablation or the undermining by wind of
a slabby surficial crust. Encircling the south pole is a region of
subdued relief with a paucity of craters, which displays enigmatic
quasi-linear markings believed to be ground features. Although no
satisfactory explanation of these markings has been formulated,
it seems likely that this region has been occupied repeatedly by
perennial masses of CO<SUB>2</SUB> ice, formed and maintained during
those phases of the martian precessional cycle that resulted in short
cool summers in the southern hemisphere. Such ice masses may play a role
in producing the unusual features of the central polar region. Physical
relationships suggest a local maximum frost thickness as great as
tens of meters. The possibility should be kept in mind that remnants
of perennial CO<SUB>2</SUB> ice of still greater thickness may exist
locally, for example, in the `etch pit' area.
---------------------------------------------------------
Title: One year's processing and interpretation - An overview.
Authors: Leighton, R. B.; Murray, B. C.
1971JGR....76..293L Altcode:
A total of 201 complete television frames of Mars were returned
by Mariners 6 and 7 in late July and early August of 1969. During
the subsequent year over 3500 different versions of those frames
were generated by computer processing involving the production
of about 35,000 individual photographic prints and large amounts
of computer printout as well. This extensive data processing and
distribution required the significant participation of about fifteen
scientists, engineers, and technicians, mainly at the Jet Propulsion
Laboratory. During that same year, the processed data were analyzed and
interpreted by approximately twenty-five scientists and technicians at
six different institutions. The special supplement of which this is
the introductory paper presents most of the scientific findings that
have accrued during the first year following the Mariner 6 and 7 flybys
of Mars. It constitutes a final report on the television experiment,
although significant efforts are continuing. Preliminary results
were presented in three papers published in August and October of 1969
[Leighton et al., 1969a, b, c]. Smith [1970] presented information about
the size, shape, and surprisingly low albedo of the martian satellite
Phobos. Information concerning various aspects of the camera and data
systems has also been published recently [Danielson, 197O].
---------------------------------------------------------
Title: Mariner 6 and 7 Television Pictures: Preliminary Analysis
Authors: Leighton, R. B.; Horowitz, N. H.; Murray, B. C.; Sharp,
R. P.; Herriman, A. H.; Young, A. T.; Smith, B. A.; Davies, M. E.;
Leovy, C. B.
1971IAUS...40..259L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Analog Video Magnetograms in Real Time
Authors: Smithsons, R. C.; Leighton, R. B.
1971IAUS...43...76S Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Mariner Mars 1969: Atmospheric results.
Authors: Leovy, C. B.; Smith, B. A.; Young, A. T.; Leighton, R. B.
1971JGR....76..297L Altcode:
Results of investigation of probable atmospheric effects appearing
in Mariner '69 TV pictures that have undergone noise removal
and preliminary decalibration are described. Two distinct types
of haze are distinguished: north polar haze, seen prominently
against the face of the planet in blue photographs, and thin haze,
usually identified by its appearance on the limb and not strongly
colored. Thin haze is surprisingly widespread, particularly in the
southern hemisphere. Discrete bright features, which may be evidence for
condensation on the ground or in the atmosphere, are described. These
occur where bright features have often been seen from earth, in a
region where very large multiple-ringed structures seem to dominate the
surface morphology. The speculation that these may be evidence for local
water-vapor exchange between ground and atmosphere is raised, and some
constraints on local subsurface water-vapor sources in the Mars tropics
are described. Finally, some implications of the Mariner '69 results
for atmospheric exploration by Mariner '71 are briefly discussed.
---------------------------------------------------------
Title: The Martian surface.
Authors: Leighton, R.
1971ZemVs...2...33L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: The Surface of Mars
Authors: Leighton, Robert B.
1970SciAm.222e..26L Altcode: 1970SciAm.222...26L
No abstract at ADS
---------------------------------------------------------
Title: Television Experiment for Mariner Mars 1971
Authors: Masursky, H.; Batson, R.; Borgeson, W.; Carr, M.; McCauley,
J.; Milton, D.; Wildey, R.; Wilhelms, D.; Murray, B.; Horowitz, N.;
Leighton, R.; Sharp, R.; Thompson, W.; Briggs, G.; Chandeysson, P.;
Shipley, E.; Sagan, C.; Pollack, J.; Lederberg, J.; Levinthal, E.;
Hartmann, W.; McCord, T.; Smith, B.; Davies, M.; de Vaucouleurs, G.;
Leovy, C.
1970Icar...12...10M Altcode:
The Television Experiment objectives are to provide imaging data which
will complement previously gathered data and extend our knowledge
of Mars. The two types of investigations will be fixed-feature
(for mapping) and variable-feature (for surface and atmospheric
changes). Two cameras with a factor-of-ten difference in resolution
will be used on each spacecraft for medium- and high-resolution
imagery. Mapping of 70% of the planet's surface will be provided by
medium-resolution imagery. Spot coverage of about 5% of the surface
will be possible with the high-resolution imagery. The experiment's
5 Principal Investigators and 21 Co-Investigators are organized into
a team. Scientific disciplines and technical task groups have been
formed to provide the formulation of experiment requirements for
mission planning and instrument development. It is expected that the
team concept will continue through the operational and reporting phases
of the Mariner Mars 1971 Project.
---------------------------------------------------------
Title: Mariner 6 and 7 Television Pictures: Preliminary Analysis
Authors: Leighton, R. B.; Horowitz, N. H.; Murray, B. C.; Sharp,
R. P.; Herriman, A. H.; Young, A. T.; Smith, B. A.; Davies, M. E.;
Leovy, C. B.
1969Sci...166...49L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Mariner 6 Television Pictures: First Report
Authors: Leighton, Robert B.; Horowitz, Norman H.; Herriman, Alan
G.; Young, Andrew T.; Smith, Bradford A.; Davies, Merton E.; Leovy,
Conway B.
1969Sci...165..684L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Mariner 7 Television Pictures: First Report
Authors: Leighton, Robert B.; Horowitz, Norman H.; Murray, Bruce C.;
Sharp, Robert P.; Herriman, Alan G.; Young, Andrew T.; Smith, Bradford
A.; Davies, Merton E.; Leovy, Conway B.
1969Sci...165..787L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: A Model Study of Persistent Magnetic Regions
Authors: Leighton, Robert B.
1969BAAS....1Q.284L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Infrared and Optical Measurements of the Crab Pulsar NP 0532
Authors: Neugebauer, G.; Becklin, E. E.; Kristian, J.; Leighton,
R. B.; Snellen, G.; Westphal, J. A.
1969ApJ...156L.115N Altcode:
Observations of the pulsating component of NP 0532 at 2.2 and 1.65 ~
are given. The energy density per pulse at 2.2 p is (3.2 ± 0.4) X 1O~'
J m~ Hz' and forms a smooth continuation of the visual data
---------------------------------------------------------
Title: A Magneto-Kinematic Model of the Solar Cycle
Authors: Leighton, Robert B.
1969ApJ...156....1L Altcode:
A simple kinematical model of the solar cycle, based upon
field amplification by the solar differential rotation, is
presented. Numerical solutions of the model equations are found which
are in close quantita- tive agreement with Spoerer's Law of Zones,
Maunder's butterfly diagram, and the poleward migration of polar
prominences. Fluctuations in eruption rate are introduced and are
shown to produce fluctuations in period, amplitude, and relative phase
and amplitude in the two solar hemispheres which agree closely with
observed values
---------------------------------------------------------
Title: The Distribution of Infrared Stars
Authors: Hughs, Evan E.; Neugebauer, G.; Leighton, R. B.
1969BAAS....1S.193H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Two-micron sky survey; a preliminary catalog.
Authors: Neugebauer, G.; Leighton, Robert B.
1969NASSP3047.....N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Two-micron sky survey. A preliminary catalogue
Authors: Neugebauer, G.; Leighton, R. B.
1969tmss.book.....N Altcode: 1969IRC...C......0N
No abstract at ADS
---------------------------------------------------------
Title: Erratum: Further Observations of Extremely Cool Stars
Authors: Ulrich, B. T.; Neugebauer, G.; McCammon, D.; Leighton, R. B.;
Hughes, E. E.; Becklin, E.
1967ApJ...147..858U Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Further Observations of Extremely Cool Stars
Authors: Ulrich, B. T.; Neugebauer, G.; McCammon, D.; Leighton, R. B.;
Hughes, E. E.; Becklin, E.
1966ApJ...146..288U Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Behavior of Carbon Dioxide and Other Volatiles on Mars
Authors: Leighton, Robert B.; Murray, Bruce C.
1966Sci...153..136L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Comments on the Mariner IV Photographs of Mars
Authors: Leighton, R. B.
1966lupl.conf..273L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Magnetic Fields in the Solar Photosphere
Authors: Leighton, R. B.
1966sowi.conf..177L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Mariner IV Photography of Mars: Initial Results
Authors: Leighton, Robert B.; Murray, Bruce C.; Sharp, Robert P.;
Denton Allen, J.; Sloan, Richard K.
1965Sci...149..627L Altcode:
The 22 photographs of Mars taken by Mariner IV have been successfully
received on earth. The Martian surface photographed is rather densely
populated with impact craters whose sizes range up to at least 120
kilometers in diameter. We infer that the visible Martian surface is
extremely old and that neither a dense atmosphere nor oceans have been
present on the planet since the cratered surface was formed.
---------------------------------------------------------
Title: Observations of Extremely Cool Stars.
Authors: Neugebauer, G.; Martz, D. E.; Leighton, R. B.
1965ApJ...142..399N Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Solar Astronomy Neglected
Authors: Howard, Robert; Leighton, Robert; Zirin, Harold; Whitford,
A. E.
1965Sci...147.1087H Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Introductory report
Authors: Leighton, R.
1965IAUS...22..158L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Transport of Magnetic Fields on the Sun.
Authors: Leighton, Robert B.
1964ApJ...140.1547L Altcode:
The dispersal and migration of unipolar and bipolar magnetic
regions on the Sun are quantitatively interpreted as a random-walk,
diffusion-like process caused by supergranulation convection currents
in the Sun's outer layers The time-dependent strength and sign of the
polar fields are deduced approximately from the positions, fluxes, and
axial tilts of the individual spot groups associated with the sunspot
cycle. The well-known predominance of the preceding spot of a group
is attributed to a characteristic field configuration which renders p
spots relatively stable against fragmentation by the supergranulation
currents The relation of the random-walk process to the solar cycle
is briefly discussed, and the 11-year period is interpreted as the
summation of five more-or-less distinct parts
---------------------------------------------------------
Title: Velocity Fields in the Solar Atmosphere. III. Large-Scale
Motions, the Chromospheric Network, and Magnetic Fields.
Authors: Simon, G. W.; Leighton, R. B.
1964ApJ...140.1120S Altcode:
Results of a detailed study of large-scale cellular motions in the solar
photosphere are presented. The velocity cells (called "supergranules")
are of various sizes and shapes and have an average diameter of 32000
km and a 20-hour lifetime; the motion within each cell is mainly
horizontal, proceeding from the center toward the outer boundary
with a velocity of 0.3-0.5 km/sec. A strong spatial correspondence is
found between the cell boundaries and several other features: (1) the
chromospheric Ca+ X 3934 network; (2) the network of descending matter
(1.0-2.0 km/sec) observed in Ha and Hp; and (3) the magnetic field
pattern. The characteristics of the velocity cells suggest that they
are non-stationary convection currents originating perhaps at a quite
deep level inside the convective envelope. These observations, together
with the theoretical predictions of Parker (1963a, b) and Osterbrock
(1961), suggest an explanation for the origin of the chromospheric
network seen in Ca+ and in the Balmer lines
---------------------------------------------------------
Title: Velocity Fields in the Solar Atmosphere. II. The Oscillatory
Field.
Authors: Noyes, Robert W.; Leighton, Robert B.
1963ApJ...138..631N Altcode:
From a systematic visual study of sets of "Doppler plates" obtained
at the 13-foot spectroheliograph of the Mount Wilson Observatory
during 1960 and 1961, the following results were derived: a) Vertical
oscillatory motions were found in all medium-strong lines observed. The
average period of the motions, about 290 sec, is a well-determined
quantity for each spectral line. Slight, but apparently real,
variations between the weaker and stronger lines observed suggest that
the average period gradually decreases with increasing altitude in
the line-forming regions of the upper photosphere. b) An oscillatory
fluctuation of residual intensity was found in the cores of the stronger
lines observed. The average period is somewhat shorter than that of
the velocity oscillations and also exhibits an apparent decrease with
increasing altitude. The two oscillations bear a definite phase relation
to each other, indicating that they are physically connected. Intensity
oscillations were not found in the weaker lines observed or in the core
of Ha. These observations are discussed and compared with expectations
for a plane wave propagating vertically through an isothermal atmosphere
with an altitude-dependent radiative relaxation time.
---------------------------------------------------------
Title: Correlations between Large-Scale Photospheric and Chromospheric
Motions, CA I (K) Emission, and Magnetic Fields.
Authors: Simon, George W.; Leighton, Robert B.
1963AJ.....68S.291S Altcode:
Nuovo Cimento Suppi. 22, 321,1961; Leighton, R., Noyes, R., and Simon,
G. Astrophys. J. 135, 474, 1962), large-scale, principally horizontal,
motions have been observed in the solar photospliere. These motions
have a cellular appearance, ai~d the flow proceeds from the center
of each "cell" toward the outer boundary, with velocities of 0.3-0.5
km/sec. These cells are arranged in a more-or-less regular pattern
over the solar surface, with an average cell diameter of 3.0-3.5 X 10~
km. Cross-correlation measurements obtained by superposition of velocity
plates and Ca+(X3933) plates show that the K2,3 emission network
occurs directly above the boundaries of the velocity cells. Downward
velocities of 1.0-2.0 km/sec are observed in the wings of Ha (Ax=0.7 A)
and HP (AX=0.4A). These localized motions exist in a network pattern
which coincides with the position of the K2,3 emission and the velocity
cell boundaries. The lifetime of the K2,3 network has been measured by
cross-correlating plates taken at various time intervals and has a mean
life of 17-21 h in excellent agreement with the finding of C. Macris
(Mcm. Soc. Astron. Ital. 33, 85,1962). Using magnetograph measurements
obtained by R. Howard (Astrophys. J. 130, 193, 1959), we find a very
high degree of correlation between the positions of weak magnetic
fields (1.5-5.0 G) and the K2,3 network. The probability that the
observed correlation is a random statistical ~uctuation is 10-~. For
stronger fields (>~ 5 G) the corresponding probability is less than
10-11. These observations suggest that the average solar magnetic field
(0.5-1.0 G) is swept to the cell boundaries by the horizontal currents,
and concentrates there in strengths perhaps two to ten times greater
than the average field. These narrow regions of enhanced field strength
could then account for the presence of the K2,3 emission at the cell
boundaries, and perhaps also for the downflow of chromospheric material
in this region, as well as small "dots" of rising material seen at the
edges of the downward flowing network, which may be spicules seen on
the disk. This work was assisted by the Office of Naval Research.
---------------------------------------------------------
Title: The Solar Granulation
Authors: Leighton, Robert B.
1963ARA&A...1...19L Altcode:
No abstract at ADS
---------------------------------------------------------
Title: Velocity Fields in the Solar Atmosphere. I. Preliminary Report.
Authors: Leighton, Robert B.; Noyes, Robert W.; Simon, George W.
1962ApJ...135..474L Altcode:
Velocity fields in the solar atmosphere have been detected and measured
by an adaptation of a technique previously used for measuring magnetic
fields Data obtained during the summers of 1960 and 1961 have been
partially analyzed and yield the following principal results: 1. Large
"cells" of horizontally moving material are distributed roughly
uniformly over the entire solar surface. The motions within each
cell suggest a (horizontal) outward flow from a source inside the
cell. Typical diameters are 1.6 X 10 km; spacings between centers,
3 X 10 km ( 5 X 10 cells over the solar surface); r.m S. velocities
of outflow, 0.5 km sec-1 lifetimes, sec. There is a similarity
in appearance to the Ca+ network. The appearance and properties
of these cells suggest that they are a surface manifestation of a
"supergranulation" pattern of convective currents which come from
relatively great depths inside the sun. 2. A distinct correlation
is observed between local brightness fluctuations and vertical
velocities: bright elements tend to move upward, at the levels at
which the lines Fe X 6102 and Ca X 6103 are formed. In the line Ca
X 6103, the correlation coefficient is 0.5. This correlation appears
to reverse in sign in the height range spanned by the Doppler wings
of the Na D1 line and remains reversed at levels up to that of Ca+ X
8542. At the level of Ca X 6103, an estimate of the mechanical energy
transport yields the rather large value 2 W cm . 3. The characteristic
"cell size" of the vertical velocities appears to increase with
height from 1700 km at the level of Fe X 6102 to 3500 km at that
of Na X 5896. The r.m s. vertical velocity of 0 4 km appears nearly
constant over this height range. 4. The vertical velocities exhibit
a striking repetitive time correlation, with a period T = 296 * 3
sec. This quasi-sinusoidal motion has been followed for three full
periods in the line Ca 6103, and is also clearly present in Fe X 6102,
Na X 5896, and other lines. The energy contained in this oscillatory
motion is about 160 J cm the "losses" can apparently be compensated for
by the energy transport (2). 5. A similar repetitive time correlation,
with nearly the same period, seems to be present in the brightness {
observed on ordinary spectroheliograms taken at the center of the Na D1
line. We believe that we are observing the transformation of potential
energy into wave energy through the brightness-velocity correlation
in the photosphere, the upward propagation of this energy by waves
of rather well-defined frequency, and its dissipation into heat in
the lower chromosphere. 6. Doppler velocities have been observed at
various heights in the upper chromosphere by means of the Ha line. At
great heights one finds a granular structure with a mean size of about
3600 km, but at lower levels one finds predominantly downward motions,
which are concentrated in "tunnels" which presumably follow magnetic
lines of force and are geometrically related to the Ca+ network. The
Doppler field changes its appearance very y at higher levels, typical
lifetimes being about 30 seconds.
---------------------------------------------------------
Title: The Solar Magnetic Field in Plage Regions
Authors: Leighton, R. B.
1962IAUTB..11..437L Altcode:
No abstract at ADS
