Author name code: thackeray
ADS astronomy entries on 2022-09-14
=author:"Thackeray, A.D."
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Title: Second Conference on Co-ordination of Galactic Research
Authors: Blaauw, A.; Larsson-Leander, G.; Roman, N. G.; Sandage, A.;
Weaver, H. F.; Thackeray, A. D.
Bibcode: 2016sccg.book.....B
Altcode:
Preface; Introduction; Part I. Clusters and Associations:
1. Introduction; 2. Clusters and stellar evolution; 3. A standardized
cluster program; 4. Trumpler's catalogue; 5. Discovery of new clusters;
6. The H-R diagram and stellar evolution; 7. Associations; Part II. The
Galaxy: 1. Introduction on the importance of stellar evolution for
problems of galactic structure; 2. Some properties of other stellar
systems; 3. The galactic halo; 4. The nuclear region; 5. The galactic
dish; 6. Spiral structure; 7. Local structure and stellar motions;
Part III. The Magnetic Clouds: 1. Introduction; 2. Optical programmes;
3. Future needs; 4. Radio work; Part IV. Summary of Discussions and
Desiderata: 1. Galactic clusters and O associations; 2. Cephoids;
3. Double and multiple stars; 4. Spiral structure; 5. Optical work on
interstellar lines; 6. H II regions; 7. Special regions; 8. Accurate
spectrophotometry; 9. Trigonometric parallaxes; 10. Determination of K;
11. Radial velocities; 12. Nucleus and disk; 13. Halo; 14. Magellanic
clouds; Appendix 1. Report of the Committee on Photometric Standards;
Appendix 2. Photometric system; Appendix 3. Technique of observation;
Appendix 4. Standards; References.
Title: Further spectroscopic observations of GG Car.
Authors: Hernandez, C. A.; Lopez, L.; Sahade, J.; Thackeray, A. D.
Bibcode: 1981PASP...93..747H
Altcode:
Spectrograms of GG Car were made at the Bosque Alegre Astrophysical
Station of the Cordoba Observatory, Argentina in 1950 and 1951 with a
dispersion of 42 A/mm; at the Radcliffe Observatory, South Africa in
1953-56 with dispersions of 29.6 A and 49.3 A/mm at H-gamma, and at
the Cerro Tololo Inter-American Observatory, Chile in 1968-70, 1976
and 1979. Radial velocities of the P Cygni H absorptions were plotted,
distribution versus time, and a 31-day period was established for the
binary system. The component that is behind at eclipse is surrounded by
an expanding, thick, extended envelope that does not permit observation
of the lines arising in the stellar photosphere. The thick envelope is
expanding with a velocity of 140 km/sec, with forbidden Fe II forming
in a lower density level. It is speculated that the weak H emission
originates from an envelope that surrounds the whole system.
Title: An improved spectroscopic orbit for alf1 Cru.
Authors: Thackeray, A. D.; Wegner, G.
Bibcode: 1980MNRAS.191..217T
Altcode:
The radial velocity measurements of the long-period spectroscopic
binary Alpha 1 Cru are presented. These new observations cover the
maximum of the radial velocity curve and yield an improvement on the
orbital elements found by Thackeray and Hill (1974). The new gamma
velocity strengthens the proposed membership of Alpha 1 Cru in the
Sco-Cen association.
Title: Additional radial velocities of supergiants in the Small
Magellanic Cloud.
Authors: Thackeray, A. D.
Bibcode: 1978MNRAS.184..699T
Altcode:
Additional radial velocities of 28 SMC supergiants determined in the
years 1959-1969 at the Radcliffe Observatory are presented. These
and other measures from ESO and elsewhere are intercompared. The mean
Radcliffe velocities have an internal standard error of + or - 4.7 km/s,
and a systematic error exceeding 4 km/s is regarded as unlikely. Eight
stars in the SMC core have a corrected velocity dispersion of only
6.9 km/s, similar to Feast's (1970) values for H II regions in the
core. But the core H II regions have a velocity differential of -20
km/s relative to these stars. The velocity dispersion for stars in
other parts of the Cloud is of the order of 15 km/s, as previously
found. Two possibly variable-velocity stars are discussed without
reaching a satisfactory conclusion.
Title: The velocity system of the Radcliffe cassegrain d-camera
Authors: Thackeray, A. D.; Wood, R.
Bibcode: 1978Obs....98...65T
Altcode:
No abstract at ADS
Title: Infrared Fe II lines in Eta Carinae and a possible
interpretation of infrared excesses.
Authors: Thackeray, A. D.
Bibcode: 1978MNRAS.182P..11T
Altcode:
The identification of very strong emission lines in the near infrared
spectrum of Eta Carinae with newly recognized high-level transitions
of Fe II raises the possibility that the infrared excesses of hot
emission-line stars may be due to dielectronic recombination of
Fe II. Johansson's Fe II lines also need to be considered in the
interpretation of the infrared spectra of supernovae.
Title: Proper motions in the outer shell of Eta Carinae.
Authors: Walborn, N. R.; Blanco, B. M.; Thackeray, A. D.
Bibcode: 1978ApJ...219..498W
Altcode:
Proper motions have been determined for discrete features in the complex
outer shell of Eta Carinae, from plates taken during 1949-1950 and
1975. Two condensations north of the central object have tangential
velocities in excess of 1000 km/s, the highest yet observed in the Eta
Car nebulosity. On the other hand, the outermost features move more
slowly, which implies ejection, possibly during the fifteenth century,
on the assumption of uniform motions.
Title: Peter Kirchhoff: Obituary
Authors: Thackeray, A. D.
Bibcode: 1978MNSSA..37....2T
Altcode:
No abstract at ADS
Title: Astronomy and Astrophysics Abstracts: Book Review
Authors: Thackeray, A. D.
Bibcode: 1978MNSSA..37...14T
Altcode:
No abstract at ADS
Title: The red/infrared spectrum of CPD -56 8032
Authors: Thackeray, A. D.
Bibcode: 1977Obs....97..165T
Altcode:
No abstract at ADS
Title: Spectra of the low-excitation nebulosities around AG Carinae
and HD 138403.
Authors: Thackeray, A. D.
Bibcode: 1977MNRAS.180...95T
Altcode:
Summary. Complex splitting of lines in the ring nebula surrounding
the P Cyg supergiant AG Car is observed and discussed. The system is
contrasted with the low-excitation planetary nebula HD 138403 (with a
more normal Of nucleus) in which new emission lines are found without
observed splitting. They include Oi, [0 I], Si II, [S III], and (in
nucleus) unidentified 4504, 4485. AG Car is also compared with such
objects as P Cyg, FG Sge, Eta Car and S bor.
Title: He-3 1863, An Unusual Be Star at High Latitude
Authors: Thackeray, A. D.
Bibcode: 1977MNSSA..36...51T
Altcode:
No abstract at ADS
Title: The evolution of the nebular spectrum of the slow nova RR
Telescopii
Authors: Thackeray, A. D.
Bibcode: 1977MmRAS..83....1T
Altcode:
Results of spectroscopic observations of the slow nova RR Tel
obtained from 1951 to 1973 with a Cassegrain, a Newtonian, and a coude
spectrograph are compiled in order to present lists giving the intensity
variations of all emission lines, wavelengths and identifications for
these lines, and forbidden lines due to ions of argon and heavier
elements. Mean radial velocities of RR Tel relative to the sun are
derived separately from 13 H lines, 9 He I lines, 13 Ti II lines,
13 Fe II lines, and 12 Fe II forbidden lines. Temporal changes in
the Balmer series are examined along with the behavior of numerous
forbidden and allowed emission lines. The forbidden-line wavelengths
are compared with those predicted on the basis of laboratory data,
the complex structure of various very strong lines is analyzed, and
a general working hypothesis is proposed that can account for some of
the salient features observed. Four main stages are distinguished in
the development of novae, and five nebular spectra are delineated. The
nature (binary or single) of RR Tel is considered.
Title: Radial velocities and distances of OB stars at the solar
distance to the galactic centre.
Authors: Crampton, D.; Bernard, D.; Harris, B. L.; Thackeray, A. D.
Bibcode: 1976MNRAS.176..683C
Altcode:
New radial velocities, spectral types and H7 equivalent widths are given
for 16 stars on the solar galactocentric circle. These observations are
combined with other recent data to estimate the distance to the galactic
centre. A value of 8 kpc is obtained but evidence that non-circular
motions are present make the method somewhat unreliable, at least until
the nature of the noncircular motions is known. The compatibility of
the observations with Kerr's expansion model of the Galaxy is discussed.
Title: HD 5980
Authors: Feast, M. W.; Thackeray, A. D.
Bibcode: 1976IAUC.2991....2F
Altcode:
M. W. Feast and A. D. Thackeray, South African Astronomical Observatory,
draw attention to the following erratum, published in Monthly
Notices Roy. Astron. Soc. (1972) 155, 383, concerning HD 5980 = R14
(cf. IAUC 2989): "In Fig. 3 [of Feast et al. 1960, ibid. 121, 337],
the identification of R14 (HD 5980) should refer to the star 6.5 mm
to the left of the marked 'star', which is in fact a compact group
[HD 5942] surrounded by a faint nebulosity."
Title: Ionized Manganese in the infrared spectrum of eta Carinae
Authors: Thackeray, A. D.; Velasco, R.
Bibcode: 1976Obs....96..104T
Altcode:
No abstract at ADS
Title: Cobalt in Eta Carinae.
Authors: Thackeray, A. D.
Bibcode: 1976MNRAS.174P..59T
Altcode:
Support for identifying A i in Eta Carinae with [Co ii] is found in
the presence of seven more possible identifications of weak lines in
that region. But computed transition probabilities are required to
confirm the suggestion. Several of these weak lines occur in RR Tel
with behaviour consistent with identification with [Co ii].
Title: Exploring the Galaxies: Book Review
Authors: Thackeray, A. D.
Bibcode: 1976MNSSA..35..128T
Altcode:
No abstract at ADS
Title: The Nebular Variables: Book Review
Authors: Thackeray, A. D.
Bibcode: 1976MNSSA..35...17T
Altcode:
No abstract at ADS
Title: Nickel and copper in the Orion nebula (Addendum)
Authors: Thackeray, A. D.
Bibcode: 1975MNRAS.173P..67T
Altcode:
No abstract at ADS
Title: Nickel and copper in the Orion nebula.
Authors: Thackeray, A. D.
Bibcode: 1975MNRAS.172P..49T
Altcode:
The probable presence of three lines of Ni ii and one of Cu ii in
published spectra of the Orion nebula is pointed out.
Title: Note on radial velocities of southern stars
Authors: Thackeray, A. D.
Bibcode: 1975BICDS...9....3T
Altcode:
No abstract at ADS
Title: Observations of rapid blue variables - XVI. VZ Sculptoris.
Authors: Warner, B.; Thackeray, A. D.
Bibcode: 1975MNRAS.172..433W
Altcode:
High speed photometry of the fifteenth magnitude nova-like variable
VZ Scl is reported. The light curve resembles that of DQ Her and
U Gem. An improved period of od.i446222o is derived. Measurements
of oo-in. spectra provide a radial velocity curve. Apparent maximum
velocity occurs near mid-eclipse, and the velocity curve is markedly
non-sinusoidal. These features are interpreted as effects of a hot
spot in the system.
Title: Galactic objects with the largest known radial velocities
Authors: Thackeray, A. D.
Bibcode: 1975Obs....95..100T
Altcode:
No abstract at ADS
Title: On Seeing the Earth's Terminator
Authors: Thackeray, A. D.
Bibcode: 1975MNSSA..34C..14T
Altcode:
No abstract at ADS
Title: Symposium introduction.
Authors: Thackeray, A. D.; Cillie, G. G.
Bibcode: 1975MNSSA..34...34T
Altcode:
No abstract at ADS
Title: Radcliffe Observatory, Pretoria. Report for the year ended
1974 March 31.
Authors: Thackeray, A. D.
Bibcode: 1974QJRAS..15..516T
Altcode: 1974QJRAS..15..516.
No abstract at ADS
Title: A supplementary list of southern O stars.
Authors: Thackeray, A. D.; Andrews, P. J.
Bibcode: 1974A&AS...16..323T
Altcode:
32 southern 0 stars that do not appear in Goy's general catalogue are
listed. UBV photometry is presented for some of these stars and of
some others in the Goy catalogue. The heaviest concentrations of 0
stars occur in Carina-Centaurus, Norma and Cygnus. Known southern O
stars in the "inner region" (1 = 27O#90) form as much as 63% of the
total. Key words: Stellar Catalogue - 0 type Stars Catalogue
Title: Variations of S Dor and HDE 269006.
Authors: Thackeray, A. D.
Bibcode: 1974MNRAS.168..221T
Altcode:
S Dor has recovered from a deep minimum which lasted 10 yr. its
radial velocity determined from [Fe ii] emission undistorted by P
Cyg absorption has remained constant between 1955 and 1970. Fe ii is
as diffuse as [Fe ii] emission when the star is faintest because of
freedom from P Cyg absorption at that stage. HDE 269006 is shown to be
a new instance of variation of S Dor type in the LMC but at a higher
temperature. Both objects show expanding relatively cool shells, are
redder at maximum and show [Fe ii] emission at minimum. Other cases
might be discovered by long-term monitoring. These two variables are
compared with Hubble-Sandage variables in external galaxies. The
latter cover a wide range of colours and the best studied cases
appear to be of considerably later type. Visual luminosities are
comparable (Mv -9.4). Eta Car is distinguished from the LMC variables
at minimum mainly by the strong wide wings accompanying sharp [Fe ii],
Fe ii, etc., although the LMC variables have similar, but weak, wings
accompanying Balmer lines at maximum; at minima such wings must fade
or be obscured. The Eta Car wings are attributed to the inner regions
of the nebulous halo which forms a remnant of the 1843 outburst.
Title: The evolution of the Wolf-Rayet features of the slow nova,
RR Telescopii.
Authors: Thackeray, A. D.; Webster, B. L.
Bibcode: 1974MNRAS.168..101T
Altcode:
Between 1951 and 1960, the spectrum of RR Tclescopii contained broad
emission bands similar to those in Wolf-Rayet stars, as well as a
narrow nebular-line spectrum. As the nebular spectrum increased in
ionization level, the equivalent Wolf-Rayet type of the bands varied
from WN 6 to WN 3 or earlier and the bands became broader. The possible
spectroscopic appearance of extremely high temperature Wolf-Rayet stars
is described. it is suggested that the bands arose in the extended
atmosphere of the nova remnant, which photoionized the outer nebula
and supplied it with kinetic energy through mass loss. The remnant
was rapidly contracting and increasing in temperature in the process
of recovering from the nova outburst.
Title: The system of α Crucis
Authors: Thackeray, A. D.; Hill, G.
Bibcode: 1974MNRAS.168...55T
Altcode:
New radial-velocity data, obtained at the Radcliffe Observatory, are
presented for the two components of cc Crucis, which exclude periods
near one day. The star cc' Crucis is a long-period spectroscopic binary
(P = 75 769 days) and cc2 Crucis is constant in velocity. The new
results imply that cc Cru should no longer be rejected from Sco-Cen
membership on grounds of radial velocity, but an unexplained difference
in radial velocity between the two components remains.
Title: Mira variables in four metal-rich globular clusters
Authors: Andrews, P. J.; Feast, M. W.; Lloyd Evans, T.; Thackeray,
A. D.; Menzies, J. W.
Bibcode: 1974Obs....94..133A
Altcode:
No abstract at ADS
Title: Spectroscopy of the eclipsing variable AR Pavonis.
Authors: Thackeray, A. D.; Hutchings, J. B.
Bibcode: 1974MNRAS.167..319T
Altcode:
Spectra of the remarkable symbiotic object AR Pavonis covering
20 years (12 eclipse periods) are analysed for radial velocities
and line-intensities. The eclipsed body shows an emission 0-type
spectrum with H, He I (triplets, singlets) N iii, He ii 4686 emission
having increasing concentration to the centre in that order. A mass
function of 0 14o is found. In the nebular spectrum the [0 iii] (4959+
5007)/4363 ratio is found to be + indicating log Ne 7, i.e. a much
higher density than planetaries and more comparable with Z And and
AG Peg; the absence of [Ne v], [Fe v] to [Fe vii] emission indicates
a lower ionization temperature for AR Pav. The forbidden emission
apparently varies with small velocity amplitude significantly out of
phase with the primary source. The secondary is believed to be M3 III
(possibly variable) whose TiO bands can be detected within 50 days
of mid-eclipse; supporting evidence is provided by observations in
J-L bands by Glass. The cF shell absorption, very strong during the
1954 egress when the variable was unusually bright, can be detected
weakly through the cycle, possibly weaker with primary behind. Radial
velocities suggest closer association with the primary than with the
secondary. A model is proposed in which the M star is filling its Roche
lobe and losing mass to the secondary through a stream which is mainly
responsible for the cF absorption. Masses of order and for the primary
and secondary are regarded as most likely. Although the distance cannot
be accurately determined the primary is estimated to have Mv - (mean)
while the system reached Mv -4 at the 1954 outburst. The changing
structure of the Balmer emission is explained as due to a hydrogen
shell surrounding the system and expanding with velocity 22 km -1
The P Cyg structure seems to have changed permanently since Sahade's
1948 observations.
Title: Further observations of interstellar gas in the GUM nebula
Authors: Thackeray, A. D.
Bibcode: 1974Obs....94...55T
Altcode:
No abstract at ADS
Title: Energy levels of Ca VII from observations of RR Telescopii.
Authors: Thackeray, A. D.
Bibcode: 1974MNRAS.167...87T
Altcode:
Three lines attributed to [Ca vii] have been found present in RR Tel
since 1967. Their measured wavelengths lead to slightly revised energy
levels of Ca vii.
Title: Co-ordinates of NGC 5139 (Omega Centauri)
Authors: Thackeray, A. D.
Bibcode: 1974MNSSA..33..109T
Altcode:
No abstract at ADS
Title: RR Lyrae variables in the Magellanic Clouds
Authors: Thackeray, A. D.
Bibcode: 1974MNSSA..33...66T
Altcode:
No abstract at ADS
Title: Note on a Possible Nova near HD 186058
Authors: Thackeray, A. D.
Bibcode: 1974MNSSA..33..131T
Altcode:
No abstract at ADS
Title: Radcliffe Observatory, Pretoria. Report for the year ended
1973 March 31.
Authors: Thackeray, A. D.
Bibcode: 1973QJRAS..14..451T
Altcode:
No abstract at ADS
Title: Early visual detection of rapidly fluctuating variable stars
Authors: Thackeray, A. D.
Bibcode: 1973Obs....93...84T
Altcode:
No abstract at ADS
Title: Spectroscopy of HD 153919 (= 2U 1700-37).
Authors: Hutchings, J. B.; Thackeray, A. D.; Webster, B. L.; Andrews,
P. J.
Bibcode: 1973MNRAS.163P..13H
Altcode:
Radial velocities of He ii 4541 (absorption) and He ii 4636 (emission)
in the O6f star HD 153919 confirm the star as the occulting body of
the source 2U 1700-37 with the period days (`973). A large scatter
may be due to the X-ray source passing through the atmosphere of the
primary. The mass of the secondary is estimated to be 2'4 M0 on the
assumption of 35 M0 for the primary.
Title: Dust in the core of the Small MagellanicCloud
Authors: Martin, W. L.; Thackeray, A. D.
Bibcode: 1973MNRAS.161P...5M
Altcode:
Of I I stars in the SMC core selected from UB V photometry as possibly
reddened early-type stars, four appear to be members, one a Be star. The
result is consistent with a normal dust content of the Cloud, but
further photometry is desirable.
Title: Absolute magnitudes of B-type primaries in visual binaries.
Authors: Andrews, P. J.; Thackeray, A. D.
Bibcode: 1973MNRAS.165....1A
Altcode:
UB V photometry is presented of 12 faint components of physical pairs
with early-type primaries, most of which are accepted as members of
the Sco-Cen association. Absolute magnitudes of the young secondaries
with types B8 V to F6 V are assumed to lie on a modified ZAMS or m
below Blaauw's MK calibration for stars selected according to apparent
magnitude; hence, through AV, absolute magnitudes of the primaries are
derived photometrically and spectroscopically. The results for seven
main-sequence stars are not significantly different from the Lesh and
Walborn calibrations of B2 V stars. The distance moduli agree with
Jones' revised values for five stars.
Title: U 1700-37.
Authors: Walker, E. N.; Thackeray, A. D.
Bibcode: 1973IAUC.2493....1W
Altcode:
No abstract at ADS
Title: Galaxies.
Authors: Burbidge, E. M.; Sersic, J. L.; Vorontsov-Vel'Yaminov, B.;
Thackeray, A. D.
Bibcode: 1973IAUTA..15..357B
Altcode:
No abstract at ADS
Title: Radial velocities of southern B stars determined at the
Radcliffe Observatory—VII
Authors: Thackeray, A. D.; Tritton, S. B.; Walker, E. N.
Bibcode: 1973MmRAS..77..199T
Altcode:
No abstract at ADS
Title: Radial velocities of southern B stars determined at the
Radcliffe Observatory@VII
Authors: Thackeray, A. D.; Tritton, S. B.; Walker, E. N.
Bibcode: 1973MNRAS.165..431T
Altcode:
Radial velocities and MK spectral classifications of 164 southern
stars with HD types B and earlier are presented. Cape UBV photometry is
available for nearly all the stars. For 116 stars there is no previously
published velocity. The compilation essentially completes the survey of
velocities of early-type stars brighter than 7.5 m over the whole sky.
Title: S Doradus.
Authors: Thackeray, A. D.
Bibcode: 1973IAUC.2584....1T
Altcode:
No abstract at ADS
Title: Radcliffe Observatory, Pretoria. Report for the year ending
1972 March 31.
Authors: Thackeray, A. D.
Bibcode: 1972QJRAS..13..573T
Altcode:
No abstract at ADS
Title: Two Hundred Years of the Radcliffe Observatory
Authors: Thackeray, A. D.
Bibcode: 1972Natur.239..313T
Altcode:
Dr Thackeray, the Radcliffe Observer, traces the history of the
Radcliffe Observatory at Oxford and later in South Africa.
Title: The Uses of Early Type Stars for Galactic Distances
Authors: Thackeray, A. D.
Bibcode: 1972QJRAS..13..243T
Altcode:
No abstract at ADS
Title: The Magellanic Clouds.
Authors: Thackeray, A. D.
Bibcode: 1972MNSSA..31...47T
Altcode:
No abstract at ADS
Title: Errata: "The brightest stars in the Magellanic Clouds"
[Mon. Not. R. Astron. Soc., Vol. 121, p. 337 - 385 (1960)].
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1972MNRAS.155..383F
Altcode:
No abstract at ADS
Title: High-velocity gas near the Gum nebula.
Authors: Thackeray, A. D.; Warren, P. R.
Bibcode: 1972MNRAS.160P..23T
Altcode:
Radcliffe coude' spectra of HR 3462 and 3527 confirm Wallerstein and
Silk's observation of high velocity Ca II components but show three
additional components which complicate the interpretation.
Title: The Magellanic Clouds
Authors: Thackeray, A. D.
Bibcode: 1972neas.conf...19T
Altcode:
No abstract at ADS
Title: HDE 322417 and the H II region near IC 4628
Authors: Crampton, D.; Thackeray, A. D.
Bibcode: 1971Obs....91..109C
Altcode:
No abstract at ADS
Title: Radcliffe Observatory, Pretoria. Report for the year ending
1971 March 31.
Authors: Thackeray, A. D.
Bibcode: 1971QJRAS..12..320T
Altcode:
No abstract at ADS
Title: H. Knox-Shaw, 1885 Oct. 12 - 1970 April 11.
Authors: Thackeray, A. D.
Bibcode: 1971QJRAS..12..197T
Altcode:
No abstract at ADS
Title: Photometry and spectroscopy of S Doradus, 1948-1970
Authors: Alexander, J. B.; Thackeray, A. D.
Bibcode: 1971Obs....91...25A
Altcode:
No abstract at ADS
Title: Crepuscular Rays Extending below the Horizon
Authors: Thackeray, A. D.
Bibcode: 1971MNSSA..30...21T
Altcode:
No abstract at ADS
Title: Variable Hydrogen Emission and Achernar
Authors: Thackeray, A. D.
Bibcode: 1971MNSSA..30...22T
Altcode:
No abstract at ADS
Title: An identified flying object (letter)
Authors: Thackeray, A. D.; Overbeek, M. D.
Bibcode: 1971MNSSA..30..155T
Altcode:
No abstract at ADS
Title: Trigonometrical Parallaxes of LB 3303 and LB 3459
Authors: Churms, J.; Thackeray, A. D.
Bibcode: 1971IAUS...42...21C
Altcode:
No abstract at ADS
Title: A spectroscopic reconnaissance of a new beta Lyrae system
HD 72754.
Authors: Thackeray, A. D.
Bibcode: 1971MNRAS.154..103T
Altcode:
HD 72754 (B2 I: pe) is a massive system resembling fl Lyr and W Cru
spectroscopically and photometrically (secondary invisible), but
the two shallow minima ( 0'2 m) are probably mainly ellipsoidal in
origin. The mass-function derived from the spectroscopic orbit is 8'9
0, the period is 33.73 days and a sin i = 9oR . A scatter in radial
velocities from individual lines suggests that the primary is best seen
in Mg ii 4481, N ii (strong) and Si ii; also in He I but the triplets
are distorted by a shell component corresponding to the very strong
shell line He 3964. This shell shows no expansion (in contrast to fl
Lyr and W Cru). Oxygen is barely detected except for 7774 (absorption)
and 8446 (emission). Weak Fe ii emission is often seen. The infra-red
Ca ii triplet appears in emission as in supergiants. [N ii] emission is
found. Hydrogen emission (considerably sharper than in Lyr) is probably
associated with the inner Lagrangian point and is suspected to suffer
eclipse especially by the primary. The emission is cut into by very
sharp shifting absorption; the velocity cycle of this absorption is
remarkably similar to that of W Cru, showing an approaching stream
around primary minimum. During the half-cycle with primary in front
the H absorption varies smoothly like the He 3964 shell; these could
be attributed to rotating rings surrounding the whole system. The
system is probably of considerably less complexity than P Lyr in
view of the sharpness of absorption and emission and in having an
apparently non-expanding shell. Further study at higher resolution
is called for to check the possible rotation of the He 3964 shell and
marginal evidence of a tidal lag. It is found that within a group of
nine fl Lyr systems large mass- functions are statistically associated
with (a) emission and (b) early spectral type. The strength of N ii
is possibly the result of mass-transfer in a close binary revealing
material that has been nitrogen-enriched in the stellar interior. The
invisible secondary is almost certainly the more massive component. If
the primary obeys the mass-luminosity relation, values of Mv = -5'S,
mass = 180 (mass-ratio = o'7) are found to be consistent with the
photometry of a B2 Ib star at a distance of about 2 kpc.
Title: Colour-Magnitude Arrays of the Brightest Stars
Authors: Thackeray, A. D.
Bibcode: 1971ASSL...23....9T
Altcode: 1971macl.conf....9T
No abstract at ADS
Title: Survey of Principal Characteristics of the Magellanic Clouds
Authors: Thackeray, A. D.
Bibcode: 1971ASSL...23....3T
Altcode: 1971macl.conf....3T
No abstract at ADS
Title: HD 72754 - a New Be Variable Star of Beta Lyrae Type
Authors: Thackeray, A. D.; Alexander, J. B.; Hill, P. W.
Bibcode: 1970IBVS..483....1T
Altcode:
No abstract at ADS
Title: Radcliffe Observatory, Pretoria. Report for the year ending
1970 March 31.
Authors: Thackeray, A. D.
Bibcode: 1970QJRAS..11..360T
Altcode:
No abstract at ADS
Title: The excitation of M8
Authors: Thackeray, A. D.
Bibcode: 1970Obs....90...30T
Altcode:
No abstract at ADS
Title: The double-lines spectroscopic binary epsilon Lupi (HD 136504).
Authors: Thackeray, A. D.
Bibcode: 1970MNRAS.149...75T
Altcode:
The first spectroscopic orbit of the rd magnitude double-lined B3
binary E Lupi is derived. The binary is the brighter component of a
close visual binary showing signs of orbital motion in 64 years. The
triple system probably belongs to the Sco-Cen association. A fourth
distant component of A type has also been observed but is probably
not physically related.
Title: A new RR Lyr variable with very high velocity.
Authors: Alexander, J. B.; Thackeray, A. D.
Bibcode: 1970MNRAS.149...59A
Altcode:
The star C.P.D. - 74 214 (BV 1041) has been shown photometrically and
spectroscopically to be an RR Lyr variable of type c with short period
( days), very high radial velocity (+304 km s-') and Preston Index As
about 7. From the small proper motion an absolute magnitude brighter
than + I 9 (Mv) is estimated.
Title: Dr Harold Knox-Shaw (obituary)
Authors: Thackeray, A. D.
Bibcode: 1970MNSSA..29...54T
Altcode:
No abstract at ADS
Title: The spectroscopic orbit of the O-type subdwarf HD 49798.
Authors: Thackeray, A. D.
Bibcode: 1970MNRAS.150..215T
Altcode:
A spectroscopic orbit of the single-lined O6 binary HD 49798 is
derived. The period is I S477 days and a mass-function of o 272 +
is found. The Jascheks' conclusion that the primary is a hot subdwarf
(the brightest known) is confirmed in various ways. The lines of He
ii are very strong and nitrogen in various stages of ionization is
prominent; N iv is found, probably for the first time in celestial
spectra. Blended wavelengths (H + He ii) are derived for Hfl and
Hy for the purpose of radial velocities. The absence of eclipses
or of ellipsoidal variations rules out a normal O6 V star for the
primary. The system stands off in a plot of K. Wi - e2 against log P
for 0 binaries (Fig. 2). If the primary has a mass of 1 oO or less in
accordance with models of helium burning stars, the secondary must be
more massive; a secondary on the normal main sequence could then only
have a narrow range of type (late F) without becoming luminous enough
to be detectable. A white dwarf secondary would provide the easiest
way to satisfy the observations, but a spectrophotometric search for
the companion in the infra-red might be profitable.
Title: Velocity curve of W Serpentis.
Authors: Greenstein, J. L.; Hernández, C.; Milone, L.; Sahade, J.;
Thackeray, A. D.
Bibcode: 1970IBSH...16...40G
Altcode:
No abstract at ADS
Title: Research on the Magellanic Clouds, 1967-1969
Authors: Thackeray, A. D.
Bibcode: 1970MNSSA..29...19T
Altcode:
No abstract at ADS
Title: The visual double HR 3817 and 3 Centaurus A
Authors: Thackeray, A. D.
Bibcode: 1969Obs....89..235T
Altcode:
No abstract at ADS
Title: Forbidden Lines of NiIV in the Spectrum of RR Telescopii
Authors: Lambert, D. L.; Thackeray, A. D.
Bibcode: 1969Ap&SS...5..283L
Altcode:
The rich spectrum of the slow nova RR Telescopii contains several strong
unidentified lines. The possibility is re-examined that some of these
lines are due to forbidden transitions of [Ni iv]. Success is partial
but the new identifications include four strong lines (λλ5363, 5288,
5060, 5042) from the multiplet a4F-a2G.
Title: Radcliffe Observatory, Pretoria. Report for the year ending
1969 March 31.
Authors: Thackeray, A. D.
Bibcode: 1969QJRAS..10..263T
Altcode:
No abstract at ADS
Title: 35. Infrared Spectra of Eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1969LIACo..15..323T
Altcode: 1969MSRSL..17..323T
No abstract at ADS
Title: The Spectrum of Eta Carinae in the 10,000 Å Region
Authors: Thackeray, A. D.
Bibcode: 1969MNSSA..28...37T
Altcode:
No abstract at ADS
Title: Orbits of two O-type spectroscopic binaries HD 93403 and 135240
Authors: Thackeray, A. D.; Emerson, B.
Bibcode: 1969MNRAS.142..429T
Altcode:
HD 93403 (06+07.5?) is a double-lined binary with eccentric orbit
(e = ) and period days situated within the H ii region around Eta
Carinae. HD 135240 is a 5rn 09 binary apparently sharing space motion
with the triple system HD 135 i6o. Orbits have been derived for the
first time for these two binaries. A least-squares iterative programme
with pre-selected accuracy tolerance, has been developed for an iCL
1909 computer.
Title: 36. Forbidden Lines in the Spectrum of RR Tel 951-1968
Authors: Thackeray, A. D.
Bibcode: 1969LIACo..15..327T
Altcode: 1969MSRSL..17..327T
No abstract at ADS
Title: Infrared spectra of Eta Carinae.
Authors: Thackeray, A. D.
Bibcode: 1969MSRSL..25..323T
Altcode: 1969tisa.conf..323T
No abstract at ADS
Title: Forbidden lines in the spectrum of RR Tel 1951 - 1968.
Authors: Thackeray, A. D.
Bibcode: 1969MSRSL..25..327T
Altcode: 1969tisa.conf..327T
No abstract at ADS
Title: Supernova in Messier 83
Authors: Thackeray, A. D.
Bibcode: 1968S&T....36..295T
Altcode:
No abstract at ADS
Title: Erratum: the Star Cluster NGC 1866 and its Cepheids
Authors: Arp, Halton; Thackeray, A. D.
Bibcode: 1968ApJ...153.1014A
Altcode:
No abstract at ADS
Title: An early-type star with very high velocity
Authors: Thackeray, A. D.
Bibcode: 1968Obs....88...56T
Altcode:
No abstract at ADS
Title: Supernova in M83
Authors: Thackeray, A. D.; Andrews, P. J.; Wood, R.
Bibcode: 1968MNSSA..27..105T
Altcode:
No abstract at ADS
Title: An Unusual View of the Green Flash
Authors: Thackeray, A. D.
Bibcode: 1968MNSSA..27..131T
Altcode:
No abstract at ADS
Title: The Star Cluster NGC 1866 and its Cepheids
Authors: Arp, Halton; Thackeray, A. D.
Bibcode: 1967ApJ...149...73A
Altcode:
Colors and magnitudes of seven Cepheid variables and ninety-eight
non-variables have been measured in the Large Magellanic Cloud star
cluster, NOC 1866 An evolved main sequence of a few times 10 years in
age and many red giants are seen in tbe color-magnitude diagram. The
variables range between 2 6 and 3 5 days in period They all turn out to
have very similar amplitudes, light-curve shapes, and, unexpectedly,
all closely the same color index The region of the variables seems to
be very sharply bounded on the red side The sequences which emerge
from the high-accuracy measures on the giant branch seem to confirm
very well the general predictions of evolution in the giant phase
by Hofmeister, Kippenhahn, and Weigert and by Iben The cluster stars
are similar to the younger stars that are numerous in the surrounding
Large Magellanic Cloud field
Title: Measured radial velocities of Proxima Centauri
Authors: Thackeray, A. D.
Bibcode: 1967Obs....87...79T
Altcode:
No abstract at ADS
Title: Magellanic Cloud Stars
Authors: Thackeray, A. D.
Bibcode: 1967Natur.214..136T
Altcode:
The Magellanic Clouds, visible in the Southern Hemisphere, are the
nearest external galaxies. Their brightest stars can be distinguished
unambiguously with the spectroscope. A spectral survey of the 194
brightest known stars in the Large Magellanic Cloud has provided
new information on the evolution of massive stars. Such short-lived
supergiants should be seen close to their birthplace in the sky.
Title: Radial Velocity Needs and Large-Scale Galactic Structure
Authors: Thackeray, A. D.
Bibcode: 1967IAUS...30..105T
Altcode:
No abstract at ADS
Title: Coudé spectra of Eta Carinae and the strongest lines of
[Fe II] and [Ni II]
Authors: Thackeray, A. D.
Bibcode: 1967MNRAS.135...51T
Altcode:
Coud spectra of the nucleus of Carinae in the ranges of wavelength 3 I0
4250A and A have been measured. Wavelengths and estimated intensities
are listed in Table Ila and b. Garstang's transition probabilities
for [Fe II] and [Ni II] have been invaluable in assigning new
identifications, the agreement with observed intensities being very
good. Over 100 [Fe II] lines belonging to 33 multiplets and 19 [Ni II]
lines belonging to 7 multiplets are indentified. The [Fe IL] intensities
together with Garstang's data suggest an excitation temperature of order
+ 1500 K. An interesting new identification in the ultra-violet is [N I]
3466. The [Ne III] lines disappeared temporarily in 1965, and the He
I emission was simultaneously weakened. [S II] 6717, 6730 seem to have
strengthened. Displaced absorptions are prominent in the Balmer lines
and for other lines especially Ti II. Such structures vary with time.
Title: Stellar Radial Velocities in the Scorpio-Centaurus Association
and IC 944
Authors: Thackeray, A. D.
Bibcode: 1967IAUS...30..163T
Altcode:
No abstract at ADS
Title: On a Very Distant Reflection of the Setting Sun
Authors: Thackeray, A. D.
Bibcode: 1967MNSSA..26..108T
Altcode:
No abstract at ADS
Title: A Lob Sided View of the Universe
Authors: Thackeray, A. D.
Bibcode: 1967MNSSA..26..136T
Altcode:
No abstract at ADS
Title: Two new high-velocity subdwarfs
Authors: Thackeray, A. D.
Bibcode: 1966Obs....86...60T
Altcode:
No abstract at ADS
Title: The spectroscopic binary δ Pictoris
Authors: Thackeray, A. D.
Bibcode: 1966MNRAS.131..435T
Altcode:
The first spectroscopic orbit of the early-type binary 8 Pic (revised
type B o (?III)) has been derived. The period of days fits observations
at Radcliffe (1963-4), Cordoba (1949-50) and Lick Southern Expedition
(`914). A secondary spectrum is detected for the first time and a mass
ratio of I 89 j is derived; the system is a massive one with m1 sin3 i
= 0, m2 sin3 i = 0. Cousins' discovery that the star is an eclipsing
binary with two minima will eventually allow individual masses to
be calculated.
Title: Addendum: The eclipsing variable HD 161783
Authors: Thackeray, A. D.; Knipe, G. F. G.
Bibcode: 1966MNSSA..25...30T
Altcode:
No abstract at ADS
Title: The B-type spectroscopic binary HD 175544.
Authors: Thackeray, A. D.; Tatum, J. B.
Bibcode: 1966PDAO...13...19T
Altcode:
No abstract at ADS
Title: Spectral variations of the B star HD 125823
Authors: Thackeray, A. D.
Bibcode: 1966MNSSA..25....7T
Altcode:
No abstract at ADS
Title: Radial velocities of three stars
Authors: Thackeray, A. D.
Bibcode: 1966MNSSA..25...35T
Altcode:
No abstract at ADS
Title: Radial velocities of southern B stars determined at the
Radcliffe Observatory, IV. The Sco-Cen association
Authors: Thackeray, A. D.
Bibcode: 1966MmRAS..70...33T
Altcode:
No abstract at ADS
Title: Orbits of two double-lined spectroscopic binaries HD 147971
and 75759
Authors: Thackeray, A. D.
Bibcode: 1966MNRAS.134...97T
Altcode: 1966MNRAS.134...98T
HD 147971 (E Nor), discovered by the Lick observers over 50 years ago
to show two spectra, consists of two B3 V stars. Orbital elements are
derived for the first time (Table III). HD 75759 is a newly discovered
binary system, consisting of two O9 V stars, with the long period of
days and large eccentricity (Table VI). m1 sin3 i and m2 sin3 i are
and respectively in the solution. The orbital elements are remarkably
similar to those of L Ori and HD 37756. It is the central exciting
source in a large H II region (Gum 17).
Title: CaII Emission in a Young K Star
Authors: Thackeray, A. D.
Bibcode: 1966IAUS...24...44T
Altcode:
No abstract at ADS
Title: Report of the Meeting on the Magellanic Clouds
Authors: Thackeray, A. D.
Bibcode: 1966IAUTB..12..279T
Altcode:
No abstract at ADS
Title: Daytime Spectra of Comet Ikeya-Seki Near Perihelion
Authors: Thackeray, A. D.; Feast, M. W.; Warner, B.
Bibcode: 1966ApJ...143..276T
Altcode:
No abstract at ADS
Title: The Rotation of the Inner Parts of the Galactic System as
Determined from OB Stars.
Authors: Feast, M. W.; Thackeray, A. D.
Bibcode: 1965ApJ...142.1645F
Altcode:
No abstract at ADS
Title: Spectra of S Equ during eclipse
Authors: Thackeray, A. D.
Bibcode: 1965Obs....85..206T
Altcode:
No abstract at ADS
Title: Spectral classification of southern OB stars
Authors: Thackeray, A. D.
Bibcode: 1965Obs....85..201T
Altcode:
No abstract at ADS
Title: A photometric and spectroscopic study of the cluster IC 2944
Authors: Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1965MNRAS.131..121T
Altcode:
The concentrated group of 0 stars surrounded by nebulosity and
globules known as IC 2944 has been investigated photometrically and
spectroscopically. Photoelectric results ( ) are presented for 6i
stars down to 15 m. The nebulosity is too bright for photographic
photometry of the faintest stars. Radial velocities (24 stars) and
spectral classifications are available for the brighter stars. A mean
colour excess = + , corresponding to visual absorption of m is found ;
no marked variation in absorption across the cluster is found, but 8
stars of 0 type give an appreciably higher colour excess of +040. Among
the stars with observed radial velocities, the percentage of binaries
appears to be at least 50. There is no variation of radial velocity
with either spectral type or magnitude exceeding a few kilometres per
second, but a differential relativity shift between the 0 and early B
stars of order 3 to 4 km/s is possible. The Cassegrain velocities for
the K line differ systematically from the mean stellar velocities by
-7 km/s. Coude' spectra of two of the brightest stars show a double
K line with separation about I km/s; the shortward component probably
arises in an expanding cloud directly associated with the group of 0
stars. Combination of photometry and spectroscopy gives an apparent
distance modulus of + , and a true distance of kpc. Discussion of the
colour-magnitude array is hampered by uncertainties regarding membership
of faint stars, but the group must be dominated by bright stars (0 and
B types). A few red stars appear to the right of the Hertzsprung gap ;
of these, the most certain member is the brightest (HD 101712) with
a peculiar composite spectrum (M2Ib pe + B?) including [Fe IIJ emission.
Title: Spectroscopic variations of S. Doradus
Authors: Thackeray, A. D.
Bibcode: 1965MNRAS.129..169T
Altcode:
Slit spectra of S Doradus during the faintest known minimum ( B) are
compared with one taken at maximum (9.4) in 1959. [Fe II] emission is
more prominent than it was during the 1955 minimum and [N ii], [S II],
[Fe III] and [Ni ii] are all found : H and He I are present with P
Cyg structure. No "symbiotic" signs of TiO absorption are found. This
nebular spectrum could be a permanent feature (masked by the strong
continuum at maximum phase) and represent a dense low-excitation
corona like that surrounding Eta Cannae. At maximum P Cyg structure
is very well marked, with Ti 11 and Sc II relatively more prominent
than Fe II in absorption. The radial velocity derived from 9 [Fe ii]
lines at minimum is +272+ km/s. This probably represents the" true"
radial velocity of the star, whereas permitted Fe ii, Ti ii lines are
shifted longward by some 21 per cent of the total P Cyg displacement
( ). A comparison is made with similar shifts of order to 25 to 30
per cent found in some galactic P Cyg stars.
Title: Orbits of two double-lined binaries HD 140008 and 178322
Authors: Thackeray, A. D.; Hutchings, F. B.
Bibcode: 1965MNRAS.129..191T
Altcode:
Radial velocities of the spectroscopic binaries HD 140008 and 178322
are presented and orbits derived. Both stars show two very similar
spectra and periods near 12 days. The double-lined character of HD
178322 was not previously known. Membership of the Sco-Cen association
is strengthened for HD 140008 by the derived value of the y velocity;
HD 178322, regarded as a" probable member" by Blaauw, has a y velocity
deviating by + km/s from the predicted velocity.
Title: Naked-Eye Observations of the Setting of Stars and Planets
[Addendum: 1965MNSSA..24..146T]
Authors: Thackeray, A. D.
Bibcode: 1965MNSSA..24..127T
Altcode:
No abstract at ADS
Title: The Nucleus of Comet Ikeya-Seki
Authors: Thackeray, A. D.
Bibcode: 1965MNSSA..24..159T
Altcode:
No abstract at ADS
Title: The Eclipsing Variable HD 161783 (BV 420)
Authors: Thackeray, A. D.; Knipe, G. F. G.
Bibcode: 1965MNSSA..24..109T
Altcode:
No abstract at ADS
Title: Statistics of Bright Stars with unknown Radial Velocities,
Colours and Parallaxes
Authors: Thackeray, A. D.
Bibcode: 1965MNSSA..24...51T
Altcode:
No abstract at ADS
Title: The Work of the Radcliffe Observatory
Authors: Thackeray, A. D.
Bibcode: 1964JRASC..58...55T
Altcode:
No abstract at ADS
Title: Occultation of Regulus by Venus
Authors: Thackeray, A. D.
Bibcode: 1964Obs....84...37T
Altcode:
No abstract at ADS
Title: Studies of NGC 6067 and IC 2944
Authors: Thackeray, A. D.
Bibcode: 1964IAUS...20...18T
Altcode:
No abstract at ADS
Title: The Work of the Radcliffe Observatory
Authors: Thackeray, A. D.
Bibcode: 1964MNSSA..23...71T
Altcode:
No abstract at ADS
Title: Short-period variables in the Magellanic Clouds
Authors: Thackeray, A. D.
Bibcode: 1964IAUS...20..370T
Altcode:
No abstract at ADS
Title: Radial velocities as a guide to spiral structure
Authors: Thackeray, A. D.
Bibcode: 1964IAUS...20..155T
Altcode:
No abstract at ADS
Title: Faint southern B star velocities
Authors: Thackeray, A. D.
Bibcode: 1964IAUS...20...61T
Altcode:
No abstract at ADS
Title: An Exceptional Minimum of S Doradus
Authors: Thackeray, A. D.
Bibcode: 1964MNSSA..23...32T
Altcode:
No abstract at ADS
Title: Review of Magellanic Cloud problems
Authors: Thackeray, A. D.
Bibcode: 1964IAUS...20..380T
Altcode:
No abstract at ADS
Title: Radial Velocities of Five Stars
Authors: Thackeray, A. D.
Bibcode: 1964MNSSA..23...81T
Altcode:
No abstract at ADS
Title: The Southern Skies an Underworked Goldmine
Authors: Thackeray, A. D.
Bibcode: 1963SouSt..20...33T
Altcode:
No abstract at ADS
Title: Radial velocities of southern B stars determined at the
Radcliffe Observatory (paper III).
Authors: Feast, M. W.; Thackeray, A. D.
Bibcode: 1963MmRAS..68..173F
Altcode:
No abstract at ADS
Title: Recent Developments in Studies of the Magellanic Clouds
Authors: Thackeray, A. D.
Bibcode: 1963AdA&A...2..263T
Altcode:
No abstract at ADS
Title: Coude spectra of Magellanic Cloud supergiants
Authors: Thackeray, A. D.
Bibcode: 1962Obs....82..207T
Altcode:
No abstract at ADS
Title: A note on the high-velocity stars HD 214539
Authors: Thackeray, A. D.
Bibcode: 1962Obs....82...72T
Altcode:
No abstract at ADS
Title: The high-velocity star HD 151397 and its relation to NGC 6231
Authors: Thackeray, A. D.
Bibcode: 1962Obs....82...71T
Altcode:
No abstract at ADS
Title: The infra-red spectrum of Eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1962MNRAS.124..251T
Altcode:
Measured wave-lengths and intensities of 143 emission lines between
6666 and zzA in the spectrum of Eta Carinae are presented, based on
four Radcliffe coud spectra. z8 well-established lines, including the
strongest at 849oA, cannot be identified. Lines of N I, [Ar iii] and
? [Ti ii] are found. Wave-lengths of [Cr ii] lines appear to deviate
slightly from predictions and might indicate a revision of about o.5
cm- in the lower energy levels.
Title: Motions Within the Magellanic Clouds
Authors: Thackeray, A. D.
Bibcode: 1962IAUS...15..105T
Altcode:
No abstract at ADS
Title: New Members of the Large Magellanic Cloud
Authors: Thackeray, A. D.
Bibcode: 1962MNSSA..21...47T
Altcode:
No abstract at ADS
Title: The cluster NGC 6067
Authors: Thackeray, A. D.; Wesselink, A. J.; Harding, G. A.
Bibcode: 1962MNRAS.124..445T
Altcode:
Photoelectric (U, B, V) and photographic (B, V) measures of 316 stars,
mostly within an area of 95 square minutes of arc, in the rich galactic
cluster NGC 6067 are presented. Spectral classifications are available
for 30 bright stars, nearly all of which are members of the cluster. The
visual absorption is determined from the reddened B stars as o 90 and
appears to be uniform over the cluster. The apparent distance modulus
is , and the true distance kpc; this result is derived by three nearly
independent methods: (i) main-sequence fitting, (ii) spectroscopic
parallaxes, (iii) the radial velocity of the cluster (-43 km/sec). The
colour-magnitude array suggests that NGC 6o67 is similar to the Pleiades
in age and intermediate between M i i, and h and Persei. NGC 6067 is
about 15 to 20 times richer than the Pleiades. K type supergiants are
present intermediate between the positions of corresponding red branches
of M I I and h and Persei. The proportion of bright red stars is about
the same in NGC 6067 and M I I. A very well-defined Hertzsprung gap
is crossed at the top by a spriflkbng of supergiants (A to K) with Mv
about -4 to -5. The cluster occupies a central position in the Norma
Cloud, similar to M ii in the Scutum Cloud.
Title: New Members of the Small Magellanic Cloud
Authors: Thackeray, A. D.
Bibcode: 1962MNSSA..21...74T
Altcode:
No abstract at ADS
Title: The Southern Skies - An Underworked Goldmine [erratum:
1962MNSSA..21..149T]
Authors: Thackeray, A. D.
Bibcode: 1962MNSSA..21...96T
Altcode:
No abstract at ADS
Title: The infra-red spectrum of eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1961Obs....81..102T
Altcode:
No abstract at ADS
Title: Spectra of the polarized halo around eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1961Obs....81...99T
Altcode:
No abstract at ADS
Title: Astronomical spectroscopy
Authors: Thackeray, A. D.
Bibcode: 1961assp.book.....T
Altcode: 1961QB465.T5.......
No abstract at ADS
Title: Spectral classification and photometry of Southern B stars.
Authors: Feast, M. W.; Stoy, R. H.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1961MNRAS.122..239F
Altcode:
248 B stars drawn from the Cape Zone Catalogue of faint stars, from
the Tonantaintla lists of OB stars, from Selected Areas 172, 193, 194
and from the Henry Draper Catalogue have been observed for spectral
classification. Of these, 184 have been observed photoelectrically in
three colours at the Cape or Radcliffe Observatories. Corrected distance
moduli (based on MK classes and B-V photometry) are tabulated. Stars
with computed distances greater than 3 kpc are plotted on the galactic
plane (together with northern stars from Hiltner's list). A considerable
concentration of distant supergiants is found in longitudes (1") 328
to 3360. 46 Tonantaintla OB stars are nearly all classified as B2 or
earlier, but only two supergiants are found among them.
Title: Analysis of radial velocities of stars and nebulae in the
Magellanic Clouds
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1961MNRAS.122..433F
Altcode:
Radial velocities of 6i stars in the LMC are analysed together with Lick
measures of nebular velocities. It is pointed out that, in principle,
instantaneous measures of radial velocity do not distingulsh between
the rotation and translation of a solid body. A least squares solution
yields a vector 813 i 6 km/s (corrected for solar motion and galactic
rotation) which is held to be mainly due to solid- body rotation of
the LMC. The corresponding gradient of radial Velocities in the sky
is km/s/deg in p.a. 1710 in which an uncertainty of + 1.7 km/s/deg
would be contributed by a translational velocity of 100 km/s. Small
departures from this solution in the outer parts indicate some
differential rotation. Further analysis, on the basis of deVaucouleurs'
inclined plane model, yields a rotation curve which disagrees with de
Vaucouleurs but which is only slightly steeper than the corrected peak
velocities derived from 21 cm profiles. The optical velocities are
more symmetrical about the radio centre than about de Vaucouleurs'
optical centre. The mass of the LMC is derived from (a) a model of
a uniform rotating ellipsoid, (b) a model of a non-uniform rotating
ellipsoid (after Perek) and (c) Bottlinger's inteipolation formula for
differential rotation. The best estimate for the mass within 40.5 of
the centre is X 10100. The velocity-dispersion appears to be slightly
larger in the inner portions of the LMC and for the brightest stars
compared with the faintest observed. SMC stars with known velocities
cover too small an area of the sky to deduce optical evidence of the
rotation of the system. The velocitydispersion in the SMC is of order
i6 km/s, as in the LMC.
Title: CPD -69o177, A Bright White Dwarf?
Authors: Thackeray, A. D.
Bibcode: 1961MNSSA..20...40T
Altcode:
No abstract at ADS
Title: A W VIR variable in omega Centauri
Authors: Thackeray, A. D.
Bibcode: 1960Obs....80..226T
Altcode:
No abstract at ADS
Title: Some Observations of VV Puppis
Authors: Oosterhoff, P. T.; Thackeray, A. D.
Bibcode: 1960S&T....19..337O
Altcode:
No abstract at ADS
Title: 47 Tucanae : Radial velocities and spectral types of individual
stars
Authors: Feast, M. W.; Thackeray, A. D.
Bibcode: 1960MNRAS.120..463F
Altcode:
A discussion is given of the radial velocities and spectral types
of 32 stars in 47 Tuc determined from 64 plates. The spectral types
of 23 red giants lie in the range of MK types G8-M2 and luminosity
classes Il-Ill. There is a slight CN discrepancy, but the spectra
are much more normal than the extreme population II globular cluster
stars. The metal/hydrogen ratio is unlikely to be less than 1/4
normal. The spectroscopic evidence suggests that the top of the
giant branch lies below and to the red of that of other globular
clusters in the HR diagram. One red giant, not known to be a variable
star shows a variable spectrum. A mean velocity of - km/sec for the
cluster is deduced. A dependence of radial velocity on spectral type
is found. It is unlikely that this is due to the wavelength system
employed. From the velocity dispersion of the red giants it is found
that under almost any assumption the mass of 47 Tuc is unlikely to
be greater than x solar masses and taking into account the dependence
of velocity on type may well be less than >C io solar masses. The
mass/light ratio (0.3 solar units) is much less than in intermediate
spirals and elliptical galaxies. The membership and spectrum of a
bright B8 III star is discussed. Two irregniar and one semi-regnlar red
variables have spectral types in the range M2-3 Il-Ill; three regular
(2ood) red variables have types in the range lI-Ib, and are normal Me
variables. The velocities of these stars are discussed. The distance
modulus of 47 Tuc is deduced from the RR Lyrae member (HV 814). It is
shown that a distance of kpc, which follows if HV 814 has a median
absolute visual magnitude of + , fits best with the spectroscopic
absolute magnitudes of the red giants, the red variables and the
B-type member.
Title: The brightest stars in the Magellanic Clouds
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1960MNRAS.121..337F
Altcode:
Spectroscopic and photoelectric observations of individual members of
the Magellanic Clouds are presented (Sections `-7). Table II includes
spectral classifications of 50 Small Cloud objects and io5 Large Cloud
objects; of these 93 have been observed photoelectrically (mostly in
3 colours), and I I 2 have measured radial velocities. Table III also
lists 103 stars proved spectroscopically to be foreground galactic
stars. In Section 8 the observed colours of Cloud stars are compared
with intrinsic colours of galactic supergiants by Johnson (0 to A3)
and Feinstein (Ac to K ). With the exception of Johnson's dip at A3 the
least reddened Cloud stars agree well with these colours. Cloud stars
are subject to a small amount of reddening (E v =0 io) apparently
arising partly in the Clouds and partly in the Galaxy. The Cloud
reddening is greater for stars involved in nebulosity. In Section 9 the
HR diagram shows stars at Ac to A3 brighter visually than the early
B and 0 supergiants. Bolometrically, however, the brightest stars
(Mb -`i) cover this whole range of spectral types; these brightest
stars all tend to show P Cyg characteristics in their spectra and are
probably at the limit of stability for massive stars (mass iooQ). Some
peculiar emission-line stars resembling Eta Car are slightly less
luminous. The few red super-supergiants (visually among the brightest
Large Cloud members) are probably very rare objects. Photographically,
the i8th brightest known LMC member has B= . In Section Ic, a detailed
spectroscopic comparison between Cloud stars and galactic standards
is made (together with a comparison of the gas in the Large and Small
Cloud). Most of the small peculiarities noted can be attributed to very
high luminosity (e.g. narrowness of the H lines) and lack of suitable
galactic standards. In particular, no outstanding peculiarities are
found in the Ic long-period Cloud Cepheids which have been studied. A
list of z6 elements (including La ii) identified in Cloud spectra is
given. In Section ii, a discussion of the UBV photometry shows that
the reddening and intrinsic lines reinforce the essential similarity
of stars (and dust) in both Clouds and the Galaxy. In Sections 12
and 13 evidence is presented that interstellar lines due to Cloud
and galactic gas occur in spectra of stars in both Clouds. Stars
showing Cloud interstellar lines tend to be involved in nebulosity;
our stars of type earlier than Bi are all involved in nebulosity, as
in the Galaxy. The W stars and red super-supergiants also appear to
be associated with nebulous regions. In Sections 14 and 15 foreground
stars are briefly discussed. Details of the photometric evidence for
foreground galactic absorption are presented, and spectra of 3 peculiar
galactic stars are described.
Title: Frederick John Marrian Stratton (obituary)
Authors: Thackeray, A. D.
Bibcode: 1960MNSSA..19..130T
Altcode:
No abstract at ADS
Title: 47 Tucanae: The Membership of Two RR Lyrae Variables
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1960MNRAS.120...64F
Altcode:
Harvard variables 810, 814 are shown to be the first known RR Lyr
variables belonging to the globular cluster 47 Tuc. Their periods are
long for their Bailey types. Their radial velocities do not differ
significantly from that of 47 Tuc. Their spectra show only a moderate
degree of metal weakness.
Title: The Differences Among Globular Clusters: Comparison of globular
clusters in the galaxy and in the Magellanic Clouds
Authors: Thackeray, A. D.
Bibcode: 1959AJ.....64..437T
Altcode:
No abstract at ADS
Title: Report of proceedings of Radcliffe Observatory, Pretoria
Authors: Thackeray, A. D.
Bibcode: 1959MNRAS.119..391T
Altcode:
No abstract at ADS
Title: Errors in spectral classification with objective prisms
Authors: Thackeray, A. D.
Bibcode: 1959Obs....79...10T
Altcode:
No abstract at ADS
Title: Note on systematic erors in trigonometrical parallaxes
correlated with declination
Authors: Thackeray, A. D.
Bibcode: 1959Obs....79....8T
Altcode:
No abstract at ADS
Title: Recent spectra of RR Telescopii
Authors: Thackeray, A. D.
Bibcode: 1959Obs....79...11T
Altcode:
No abstract at ADS
Title: The emission line spectrum of the eclipsing variable AR Pavonis
Authors: Thackeray, A. D.
Bibcode: 1959MNRAS.119..629T
Altcode:
The bright line spectrum of AR Pav is described. During eclipse the
intensity of the H lines weakens relative to the nebular lines; He
I weakens more, while He ii 4686 nearly disappears. Stratification
as in a planetary nebula is suggested. In the P Cyg structure of the
Balmer lines the red component is always stronger than the violet,
but equality is approached for over 100 days following eclipse. The
separation of the components narrows during eclipse by an amount which
varies in different cycles. Outside eclipse the mean separation obeys
Struve's relation V3 P- for gaseous rings. A model of a thick ring
subject to differential rotation is considered and proffles computed
geometrically for various types of eclipse. The observed narrowing
of components is not reproduced in this model. As an alternative
an expanding ring is considered briefly, and this model predicts
symmetrical narrowing during eclipse.
Title: The Magellanic Clouds
Authors: Thackeray, A. D.
Bibcode: 1959IAUS....7...81T
Altcode:
No abstract at ADS
Title: Second Conference on Co-ordination of Galactic Research
Authors: Blaauw, A.; Larsson-Leander, G.; Roman, N. G.; Sandage, A.;
Weaver, H. F.; Thackeray, A. D.
Bibcode: 1959IAUS....7.....B
Altcode:
No abstract at ADS
Title: Observations of the Occultation of Regulus by Venus at the
Radcliffe Observatory
Authors: Thackeray, A. D.
Bibcode: 1959MNSSA..18...63T
Altcode:
No abstract at ADS
Title: Coronal lines in the post-maximum spectra of RS OPH 1958
Authors: Griffin, R. F.; Thackeray, A. D.
Bibcode: 1958Obs....78..245G
Altcode:
No abstract at ADS
Title: Observations of Icarus
Authors: Kinman, T. D.; Lourens, J. V. B.; Russo, T. W.; Thackeray,
A. D.
Bibcode: 1958Obs....78..202K
Altcode:
No abstract at ADS
Title: The Magellanic Clouds - spectroscopy and photometry of
bright stars
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1958Obs....78..156F
Altcode:
No abstract at ADS
Title: The Magellanic Clouds and Stellar Populations
Authors: Thackeray, A. D.
Bibcode: 1958RA......5..195T
Altcode:
No abstract at ADS
Title: Periods and light-curves of variable stars in NGC 121
Authors: Thackeray, A. D.
Bibcode: 1958MNRAS.118..117T
Altcode:
82 photographs of the globular cluster NGC 121 on the outskirts of
the Small Magellanic Cloud, covering a total range of 9 years but
mostly concentrated in three consecutive seasons, are used to derive
periods and light- curves of 5 variables within I' of the cluster. Of
these, three are short- period variables (periods between 0.50 and
days) of Bailey a and b type with the usual relations between period,
amplitude and shape of light-curve. The other two, among the reddest and
brightest of the cluster-stars, have periods of and I 12A: days. The
light-variations are presented in the form of step-estimates on a
basic" sequence. Four other short-period variables have been found on
the plates which are too far from the cluster to be members. They are
sufficiently faint to be regarded as possibly the first instance of
RR Lyr variables in the general field of the Small Magellanic Cloud.
Title: Double Stars in the Region of the Large Magellanic Cloud
Authors: Thackeray, A. D.
Bibcode: 1958MNSSA..17...56T
Altcode:
No abstract at ADS
Title: Radcliffe Observations of the Minor Planet Icarus - June 1958
Authors: Kinman, T. D.; Thackeray, A. D.; Lourens, J. Van B.; Russo,
T. W.
Bibcode: 1958MNSSA..17...70K
Altcode:
No abstract at ADS
Title: 47 Tucanae - an Interim Report
Authors: Thackeray, A. D.
Bibcode: 1958RA......5...69T
Altcode:
No abstract at ADS
Title: Analysis of radial velocities of distant B type stars
Authors: Feast, M. W.; Thackeray, A. D.
Bibcode: 1958MNRAS.118..125F
Altcode:
Radial velocities of 314 early B type stars with calculated distances
(based on photoelectric colours and MK classifications) greater than I
kpc are analysed for differential galactic rotation. The incorporation
of Radcliffe velocities of southern stars renders the distribution in
longitude much more uniform than in earlier analyses. At distances
greater than 2 kpc there is even a marked deficiency of northern
material. First-order analyses of stellar and interstellar velocities
are carried out for various distance groups (Section 5, Table III). A
negative K-term (Section 6) is found in the region I to 2 kpc, but
more distance groups do not suggest that this is due to a general
contraction of the galaxy. The possible connection with the deviation
of the vertex is briefly discussed. The K-term in the region I to 2 kpc
is diminished considerably when a systematic correction, apparently
applicable to the Lick velocities of faint B stars (Section 3), is
taken into account. The effect of this correction is also to increase
the derived values of the Oort A constant. The group of stars at
distances greater than kpc yields an abnormally low value of A, but
this is regarded as chiefly a result of selection leading to a large
proportion of overestimated distances in this group. The velocity
dispersion found for the inner part of the galaxy is not found to
have an abnormal value (Section 7). The Camm linear approximation is
used (Section 8) to derive a value of the Oort A constant. The final
value A = + km/sec/kpc is adopted. Two partly independent methods are
used to derive a value of R, the distance to the galactic centre;
the most probable value is kpc (Section 10, Table IX). A value of
0.5 for the ratio of the axes of the velocity ellipsoid appears to be
appropriate to distant B stars. The calibration of the MK luminosity
scale is tested (Section II) for stars in the range B to . A curve of
differential rotation w(R) is derived (Section 12). The results show
no significant deviation from the radio results and suggest that W#
is positive in the range of R covered by the observations.
Title: A study of bright members of the Large Magellanic Cloud
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1958IAUS....5....7F
Altcode:
No abstract at ADS
Title: Radial velocities of southern B stars determined at the
Radcliffe Observatory Part II.
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1957MmRAS..68....1F
Altcode:
No abstract at ADS
Title: Astronomical Advantages of the Southern Hemisphere
Authors: Thackeray, A. D.
Bibcode: 1957MNSSA..16...44T
Altcode:
No abstract at ADS
Title: Radial velocities of southern B stars determined at the
Radcliffe Observatory (Paper II) (summary)
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1957MNRAS.117..579F
Altcode:
In the second stage of the Radcliffe programme on radial velocities
of southern 0 and B type stars, velocities of 130 stars selected for
distance (chiefly m0 - M > I I o) are presented together with
59 stars with previously observed velocities. All the stars have
been classified on the MK system. The fainter stars demanded the
use of faster emulsions compared with Paper I, and an investigation
of residuals of the lines He 4471, 4026 has shown that for these
emulsions significant deviations from IAU wave-lengths occur which
vary with line-width, in accordance with Petrie's findings. The
Radcliffe procedure as regards wave-lengths of 4471, 4026 has been
revised accordingly. The stars of this paper with newly determined
velocities are at an average distance more than twice as great as that
of the stars in Paper I.
Title: The Cluster NGC 1786 in the Large Magellanic Cloud
Authors: Thackeray, A. D.
Bibcode: 1957MNSSA..16....3T
Altcode:
No abstract at ADS
Title: An Attempted Spectroscopic Observation of Comet Arend-Roland
Authors: Thackeray, A. D.; Feast, M. W.
Bibcode: 1957MNSSA..16...36T
Altcode:
No abstract at ADS
Title: Spectroscopic Indications of an Internal Spiral Arm in
the Galaxy
Authors: Thackeray, A. D.
Bibcode: 1956Natur.178.1458T
Altcode:
SPIRAL structure within our galaxy has been detected by three
methods: (a) space-plotting of stellar associations1,
(b) multiple structure in the H 21 cm. radiation2, (c)
multiple structure in the interstellar lines of Ca II and Na I in
distant stars3. The radio method (b) has the advantage over
the two optical methods in that it will penetrate to the limits of the
galaxy. On the other hand, the interpretation of the radio profiles for
directions within 90° of the galactic centre is greatly complicated by
the superposition of radiation from regions at very different distances
which have the same angular velocity. By contrast, method (c) can reveal
unambiguously the presence of one, two or more spiral arms within a
light-path limited by a distant star. The limited light-paths used in
method (c) are of advantage in the internal regions of the galaxy.
Title: Polarization of eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1956Obs....76..154T
Altcode:
No abstract at ADS
Title: The distance and absolute magnitude of eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1956Obs....76..103T
Altcode:
No abstract at ADS
Title: Report of proceedings of Pretoria, Radcliffe Observatory
Authors: Thackeray, A. D.
Bibcode: 1956MNRAS.116..200T
Altcode:
No abstract at ADS
Title: Red supergiants in the Large Magellanic Cloud.
Authors: Feast, M. W.; Thackeray, A. D.
Bibcode: 1956MNRAS.116..587F
Altcode:
Five members of the Large Cloud have been discovered with absolute
visual magnitudes about - , spectral types from F8 to G : and with
colours between % and Y I 45. Four of these stars are among the 30
brightest known members of the Cloud. The census of the brightest blue
stars must be regarded as complete, but owing to the difficulty of
distinction of foreground stars more red super-supergiants probably
remain to be discovered.
Title: Nocturnal Temperature Ranges, Winds and Seeing Conditions at
the Radcliffe Observatory, Pretoria
Authors: Thackeray, A. D.
Bibcode: 1956MNSSA..15...35T
Altcode:
No abstract at ADS
Title: IC 2944 - An O Type Association
Authors: Thackeray, A. D.
Bibcode: 1956MNSSA..15...20T
Altcode:
No abstract at ADS
Title: Shells around P Cygni stars
Authors: Thackeray, A. D.
Bibcode: 1956VA......2.1380T
Altcode:
The spectra of four stars, previously discovered to be surrounded by
nebulous envelopes, are briefly discussed. AG Carinae, HD 138403,
and Eta Carinae are truly described as P Cygni stars. Emission and
absorption lines are found in C.D. — 46° 11816, but the P Cygni
character of this star is not certainly established.
Title: A study of bright members of the Large Magellanic Cloud
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1955Obs....75..216F
Altcode:
No abstract at ADS
Title: Distances of the Magellanic Clouds (II)
Authors: Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1955Obs....75...33T
Altcode:
No abstract at ADS
Title: RR Telescopii in 1953 and 1954, and the development of
slow novae
Authors: Thackeray, A. D.
Bibcode: 1955MNRAS.115..236T
Altcode:
Recent developments in the emission spectrum of RR Tel include the
emergence of C iv, [A iv], [K iv], [Fe iv], [Fe v]. A special search
for the hitherto unknown [Fe iv] lines proved successful in the light
of Edien's independent predictions from laboratory data. Fe ii lines
have faded steadily relative to [Fe ii]. The rate of development
towards higher stages of ionization is compared with that of other
slow novae. Time intervals between corresponding stages of RR Pic, RR
Tel, RT Ser and Car are found to be approximately in the ratios I :
6 : 17 : 220. One result of this comparison is to give some grounds
for supposing that Car brightened from a pre-nova state not very long
before Halley's observation in 1677.
Title: Radial velocities of southern B stars determined at the
Radcliffe Observatory (Summary of paper published in the Memoris of
the R. A. S. )
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1955MNRAS.115..217F
Altcode:
The application of the Radcliffe Cassegrain spectrograph to the
determination of radial velocities together with tests of its
performance are described. Flexure effects at large hour-angles and
on reversal of the telescope are found to be insignificantly small. 59
plates of IAU standard stars (mostly from the list of faint standards)
give a zero-point difference of IAU-Radcliffe= 0 90 I (s.e.) km/s. New
velocities have been determined of 147 southern B stars selected
according to the following criteria: (I) HD type B or earlier, (2)
GC visual magnitude 7.5 or brighter, (3) Declination south of 350,
(4) odd minutes of R.A. (1950). For the great majority of these stars
the velocities depend upon five or more plates. Spectral types and
luminosities on the Morgan system have been estimated. Photoelectric
colours and magnitudes of the stars are being determined at the Cape
Observatory. In addition, radial velocities have been measured for 38
B stars, mostly southern, for comparison with velocities previously
determined at other observatories. Two diagrams (p. 218) illustrate the
galactic rotation effects as shown by 145 stars with new velocities
and by the interstellar gas (from 53 stars with wellestablished
interstellar K lines). The sample of stars observed has an average
distance probably somewhat less than I kpc. The velocities seem to be
free from systematic motions associated with the group.
Title: Note on Small Dark Clouds
Authors: Thackeray, A. D.
Bibcode: 1955LIACo...6..437T
Altcode:
No abstract at ADS
Title: Radial velocities of southern B stars determined at the
Radcliffe Observatory. (Paper 1).
Authors: Feast, M. W.; Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1955MmRAS..67...51F
Altcode:
No abstract at ADS
Title: Stars in Motion
Authors: Thackeray, A. D.
Bibcode: 1955MNSSA..14...29T
Altcode:
No abstract at ADS
Title: A Rainbow After Sunset
Authors: Thackeray, A. D.
Bibcode: 1955MNSSA..14...10T
Altcode:
No abstract at ADS
Title: Characteristics of Some Diffuse Nebulae in the Magellanic
Clouds
Authors: Thackeray, A. D.
Bibcode: 1955IAUS....2...39T
Altcode:
No abstract at ADS
Title: Another symbiotic star
Authors: Thackeray, A. D.
Bibcode: 1954Obs....74..258T
Altcode:
No abstract at ADS
Title: Spectra of the eclipsing variable AR Pavonis
Authors: Thackeray, A. D.
Bibcode: 1954Obs....74..257T
Altcode:
No abstract at ADS
Title: The excitation of emission lines in late-type variables
Authors: Thackeray, A. D.
Bibcode: 1954Obs....74..212T
Altcode:
No abstract at ADS
Title: [Fe IV] in 1953 spectra of RR Telescopii?
Authors: Thackeray, A. D.
Bibcode: 1954Obs....74...90T
Altcode:
No abstract at ADS
Title: The helium star HD 168476
Authors: Thackeray, A. D.
Bibcode: 1954MNRAS.114...93T
Altcode:
Wave-lengths of 206 absorption lines have been measured in HD 168476
between 3700 and 6700 A. No lines of hydrogen or oxygen are found,
while lines of He I, C ii and Ne I are prominent. A list is given
of the various elements represented. A large range of excitation and
ionization potentials is exhibited. Ti ii, with the same I.P. as H and
01, is definitely present. Except for H and 0, a fair match with the
spectrum of the B supergiant 67 Oph can be made, but equivalent widths
in HD 168476 are about twice those in the supergiant; this corresponds
roughly to increasing the number of atoms above the photosphere by a
factor 10. The observations are consistent with a great deficiency 9f
hydrogen causing increased transparency and the spectral characteristics
of a supergiant. The velocity -165 km/s appears to be constant. In view
of the large positive velocity of HD 160641, a similar H-weak star,
these stars must be regarded as high-velocity objects rather than as
exhibiting peculiar atmospheric motions. Proper motion data suggest
an absolute magnitude of -2 or brighter; this is supported by evidence
from a line in HD 168476 which is probably due to interstellar calcium.
Title: [Fe IV] in 1953 Spectra of RR Telescopii?
Authors: Thackeray, A. D.
Bibcode: 1954MNSSA..13....5T
Altcode:
No abstract at ADS
Title: The Distances of the Magellanic Clouds II
Authors: Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1954MNSSA..13...99T
Altcode:
No abstract at ADS
Title: Another Symbiotic Star
Authors: Thackeray, A. D.
Bibcode: 1954MNSSA..13...72T
Altcode:
No abstract at ADS
Title: Note on the spectra of K-type dwarfs in the region of H and K,
M. W. Feast and A. D. Thackeray
Authors: Feast, M. W.; Thackeray, A. D.
Bibcode: 1954MNRAS.114..635F
Altcode:
The line Si 3905 is considerably strengthened in K-type dwarfs compared
with giants. Emission cores to H and K are recorded on dense exposures
as apparently a normal feature in dwarfs of type K2 and later.
Title: Spectra of the Eclipsing Variable AR Pavonis
Authors: Thackeray, A. D.
Bibcode: 1954MNSSA..13...70T
Altcode:
No abstract at ADS
Title: Observations of the Minor Planet Icarus - 1954
Authors: Lourens, J. Van B.; Thackeray, A. D.
Bibcode: 1954MNSSA..13..100L
Altcode:
No abstract at ADS
Title: Distances of the Magellanic Clouds
Authors: Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1953Natur.171..693T
Altcode:
THE distances of 26 and 23 kiloparsecs derived by Shapley1
for the two Magellanic Clouds depend upon assuming the same absolute
magnitudes for the Cepheid variables in the Clouds and in our own
galaxy. The absolute magnitudes of the galactic Cepheids are still
subject to considerable uncertainties, and it would be more satisfactory
to use as distance-indicators the RR Lyræ variables (with periods less
than 1 day) the absolute magnitudes of which are known more accurately
and which are found in great abundance in our own galaxy. Very few such
variables, however, have been found in the Small Cloud2,
and none so far has been reported in the Large Cloud.
Title: The excitation of 4372A in long period variable stars
Authors: Thackeray, A. D.
Bibcode: 1953Obs....73...83T
Altcode:
No abstract at ADS
Title: The Spectrum of HD 141969
Authors: Thackeray, A. D.
Bibcode: 1953MNSSA..12...72T
Altcode:
No abstract at ADS
Title: Identifications in the spectra of Eta Carinae and RR Telescopii
Authors: Thackeray, A. D.
Bibcode: 1953MNRAS.113..211T
Altcode:
Wave-lengths and intensity estimates of lines in the spectra of Eta
Carinae and RR Telescopii between 3700 and 8900 A are presented. Both
spectra are characterized by strong Fe II emission, forbidden and
permitted, and by weak continua. Representations of individual
elements in the two stars are discussed in Section 4 (Eta Carinae)
and in Section 8 (RR Tel). Doubly ionized elements (especially 0, Ne,
S, A and Fe) are better represented in RR Tel which shows in 1952 a
transition between the "Eta Carinse" and "nebular" stages of a slow
nova. Oxygen lines, permitted and forbidden, are so much stronger
in RR Tel that a deficiency of 0 in Eta Carinae is rather strongly
indicated. A few unidentified lines are listed in Table VI. The
strongest (in Eta Carinae) is in the infra-red at about 8493 A. The
relative intensities of [Fe II] lines agree generally with the order
of prominence suggested in the Revised Multiplet Table, but a few
exceptions are noted (Section 6). The strongest lines in Eta Carinae
have structures characteristic of Type III in Beals's classification
of P Cygni profiles (Section 5). They are accompanied by diffuse
absorptions with velocities about -450 km/s. These absorptions are
found accompanying 12 strong [Fe II] lines. The double emission peaks
are best marked for H and [Fe III]. Similar displaced absorptions are
found in a few He lines in RR Tel with velocities -68 (1951) and -86
km/s (1952). ______________________
Title: The Distances of the Magellanic Clouds
Authors: Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1953MNSSA..12...33T
Altcode:
No abstract at ADS
Title: Note on the brightening of Eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1953MNRAS.113..237T
Altcode:
The recently reported brightening of Carinae refers to integrated
magnitudes "nucleus plus halo ". Gaviola's isophotes show that the
halo must have brightened. The brightening of the nucleus is probably
very much less.
Title: The Rome Meeting of the IAU
Authors: Thackeray, A. D.
Bibcode: 1953MNSSA..12....8T
Altcode:
No abstract at ADS
Title: Observations of the Minor Planet Icarus - August 1943
Authors: Lourens, J. Van B.; Thackeray, A. D.
Bibcode: 1953MNSSA..12...86L
Altcode:
No abstract at ADS
Title: H.D. 168476 and 124448 - two similar stars
Authors: Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1952Obs....72..248T
Altcode:
No abstract at ADS
Title: Report of proceedings of Pretoria, Radcliffe Observatory
Authors: Thackeray, A. D.
Bibcode: 1952MNRAS.112..318T
Altcode:
No abstract at ADS
Title: Hydrogen in the Universe (Presidential Address 1952)
Authors: Thackeray, A. D.
Bibcode: 1952MNSSA..11...79T
Altcode:
No abstract at ADS
Title: Naked Eye Observations of a Planet's Opposition
Authors: Thackeray, A. D.
Bibcode: 1952MNSSA..11...50T
Altcode:
No abstract at ADS
Title: Observations of the Minor Planet Icarus
Authors: Feast, M. W.; Lourens, J. Van B.; Thackeray, A. D.
Bibcode: 1952MNSSA..11..107F
Altcode:
No abstract at ADS
Title: The spectrum of eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1951Obs....71..205T
Altcode:
No abstract at ADS
Title: The spectrum of eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1951Obs....71..167T
Altcode:
No abstract at ADS
Title: The minimum and amplitude of S INDI
Authors: Thackeray, A. D.
Bibcode: 1951Obs....71...41T
Altcode:
No abstract at ADS
Title: Nova Tucanae 1951
Authors: Thackeray, A. D.
Bibcode: 1951MNSSA..10...96T
Altcode:
No abstract at ADS
Title: The Cassegrain Spectrograph of the Radcliffe Observatory
Authors: Thackeray, A. D.
Bibcode: 1951MNSSA..10...29T
Altcode:
No abstract at ADS
Title: The Spectrum of Eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1951MNSSA..10...88T
Altcode:
No abstract at ADS
Title: The Spectrum of Eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1951MNSSA..10...56T
Altcode:
No abstract at ADS
Title: Variables in the Sculptor system
Authors: Thackeray, A. D.
Bibcode: 1950Obs....70..144T
Altcode:
No abstract at ADS
Title: Additional observations and improved ephemeris of VV Puppis
Authors: Thackeray, A. D.; Wesselink, A. J.; Oosterhoff, P. Th.
Bibcode: 1950BAN....11..193T
Altcode:
No abstract at ADS
Title: A photographic survey of bright southern planetary nebulae
Authors: Evans, David S.; Thackeray, A. D.
Bibcode: 1950MNRAS.110..429E
Altcode:
Twenty-six objects believed to be planetary nebulae with diameters
greater than 8 seconds of arc, south of declination 400, have
been investigated. Descriptions, and photographs of those which
definitely are planetary nebulae, are presented. Some comments on the
classification of planetary nebulae are offered, and the proportions
exhibiting various types of symmetrical form are tabulated.
Title: Nova Scorpii 1950 and RR Telescopii
Authors: Thackeray, A. D.
Bibcode: 1950MNSSA...9...69T
Altcode:
No abstract at ADS
Title: Proxima Centauri
Authors: Thackeray, A. D.
Bibcode: 1950MNSSA...9....9T
Altcode:
No abstract at ADS
Title: Some southern stars involved in nebulosity
Authors: Thackeray, A. D.
Bibcode: 1950MNRAS.110..524T
Altcode:
An outer shell of nebulosity surrounding Eta Carinae is described. AG
Carinae,HD 138403 and CoD 460 11816 are found to be surrounded by
nebulous disks or shells with [0 III] weak or absent. These three stars
all have Harvard classification of P Cygni type and resemble planetaries
of low excitation. The spectrum of HD 138403 has some affinity to that
of the nebulosity round T Tauri. Diffuse nebulosities near HD 92207 and
CPD - 590 2661 in the neighbourhood of Eta Carinae are also described. A
complex field of bright and dark nebulosity at 11h 36rn 63007 indicates
close interaction between stars and nebulosity. The small dark areas
are highly irregular in outline and also appear to lie close to stars.
Title: Observations of the brightest regions of three diffuse nebulae
Authors: Thackeray, A. D.
Bibcode: 1950MNRAS.110..343T
Altcode:
Observations, by direct photography and spectroscopy, of the three
diffuse nebulae Mi6, M20 and M8 are presented and discussed, with
special reference to the bright rims around associated dark lanes. The
spectra of the rims are found to consist of a strengthening of the
nebular spectrum. The ratio HP!Ni is greater at or near the rims. Weak
continuous spectrum is found in the brightest rim of Mi6. Qualitative
evidence is presented that the dark matter is moving inwards towards
a central star or stars against the bright nebulosity. The brightest
part of M8 reveals a complex structure intimately associated with faint
stars. A green photograph, avoiding emission lines, reveals nuclei which
may be stellar. There is a strong continuous spectrum, in addition to
a nebular spectrum with permitted lines enhanced relative to forbidden.
Title: The Minimum Amplitude of S Indi
Authors: Thackeray, A. D.
Bibcode: 1950MNSSA...9...88T
Altcode:
No abstract at ADS
Title: Five southern stars with emission-line spectra
Authors: Thackeray, A. D.
Bibcode: 1950MNRAS.110...45T
Altcode:
Low-dispersion spectra showing bright lines of Proxima Centauri,
RR Telescopii and of three long-period variables in 47 Tucanae
are described. Proxima Centauri is of dMe type, the emission lines
apparently varying in intensity. RR Telescopii underwent a rather
abrupt transition from F-type absorption to emission plus continuous
during the period 1949. August to September.
Title: Nebulosity surrounding Eta Carinae
Authors: Thackeray, A. D.
Bibcode: 1949Obs....69...31T
Altcode:
No abstract at ADS
Title: The Kappa Crucis Cluster
Authors: Thackeray, A. D.
Bibcode: 1949MNSSA...8...30T
Altcode:
No abstract at ADS
Title: The Short-Period Variable Star VV Puppis
Authors: Thackeray, A. D.; Wesselink, A. J.
Bibcode: 1949MNSSA...8...91T
Altcode:
No abstract at ADS
Title: Line-intensities in Stars of Type G5 to K5
Authors: Thackeray, A. D.
Bibcode: 1949MNRAS.109..436T
Altcode:
No abstract at ADS
Title: The Colours of Distant Nebulae
Authors: Thackeray, A. D.
Bibcode: 1949MNSSA...8...55T
Altcode:
No abstract at ADS
Title: RR Telescopii
Authors: Thackeray, A. D.
Bibcode: 1949MNSSA...8...84T
Altcode:
No abstract at ADS
Title: CoD -62 466 and CPD -62 1643
Authors: Thackeray, A. D.
Bibcode: 1949MNSSA...8...15T
Altcode:
No abstract at ADS
Title: A Newtonian Spectrograph
Authors: Thackeray, A. D.
Bibcode: 1949MNSSA...8...57T
Altcode:
No abstract at ADS
Title: On some possible evolutionary trends in the interstellar medium
Authors: Thackeray, A. D.
Bibcode: 1948Obs....68...22T
Altcode:
No abstract at ADS
Title: The Spectrum of ρ Cassiopeiae, 1939
Authors: Tai, W. S.; Thackeray, A. D.
Bibcode: 1948MNRAS.108..271T
Altcode:
No abstract at ADS
Title: The Spectrum of ρ Cassiopeiae, 1946-1947
Authors: Thackeray, A. D.
Bibcode: 1948MNRAS.108..279T
Altcode:
No abstract at ADS
Title: Stellar Spectra
Authors: Thackeray, A. D.
Bibcode: 1948MNSSA...7...86T
Altcode:
No abstract at ADS
Title: Spectrum of ρ Cassiopeiæ
Authors: Thackeray, A. D.
Bibcode: 1947Natur.160..370T
Altcode:
THE spectrum of the irregular variable ρ Cassiopeise has been variously
classified as G7 (Victoria), cG0 (Mt. Wilson), F8p (Yerkes) and F8p
(Harvard), the last classification being accompanied by the note ``the
spectrum resembles class K0 in the region of Hβ'' The classifications
agree in attributing the spectrum to a supergiant with a luminosity
about 1,500 times that of the sun, while the surface temperature varies
irregularly in periods of the order of 200-1,000 days, about an average
not far from the solar value of 6,000° K.
Title: A Short-lived Solar Phenomenon in High Latitude
Authors: Thackeray, A. D.
Bibcode: 1947Natur.160..439T
Altcode:
ON the morning of June 19, 1947, at 09h. 46m. U.T., while scanning the
solar disk with the spectro-helioscope of the Solar Physics Observatory,
Cambridge, in Hα, light, my attention was suddenly attracted by an
intensely dark absorption flocculus near the south point of the sun. The
region had three nuclei of the order of I of arc in diameter or less,
more jet black in appearance than any flocculi I have previously
observed. There was only just time to confirm the reality of the
phenomenon and obtain a preliminary measure of its position before
clouds intervened at 09h. 481m. No sign of the flocculus could
be observed at first when the clouds cleared, but at 09h. 57m. one
nucleus (A) was picked up at a line-shifter reading corresponding to
a velocity of recession of 74 km./sec. Later, the other nuclei, B,B',
were picked up at a still higher velocity as a single marking much
fainter in contrast. The complete set of readings in the observing book,
together with the corresponding velocities, are given below:
Title: The general magnetic field of a star
Authors: Thackeray, A. D.
Bibcode: 1947Obs....67..105T
Altcode:
No abstract at ADS
Title: The Magnetic Field of a white Dwarf
Authors: Thackeray, A. D.
Bibcode: 1947MNRAS.107..463T
Altcode:
No abstract at ADS
Title: The Bright Lines Fe 4063, 4132 in T Tauri Variables and in
the Solar Chromosphere
Authors: Thackeray, A. D.
Bibcode: 1946PASP...58..301T
Altcode:
No abstract at ADS
Title: Resignation from the Secretaryship
Authors: Thackeray, A. D.
Bibcode: 1943MNRAS.103....2T
Altcode:
No abstract at ADS
Title: Short-lived H alpha prominences observed on the Sun's disk
Authors: Thackeray, A. D.
Bibcode: 1942Obs....64..204T
Altcode:
No abstract at ADS
Title: Convective equilibrium and solar limb darkening-a correction
Authors: Thackeray, A. D.
Bibcode: 1942MNRAS.102..272T
Altcode:
No abstract at ADS
Title: Colour temperatures of convective stars
Authors: Tai, W. S.; Thackeray, A. D.
Bibcode: 1942MNRAS.102..268T
Altcode:
No abstract at ADS
Title: Comparison of hydrogen and helium radiation in solar
prominences
Authors: Thackeray, A. D.
Bibcode: 1941Obs....64..169T
Altcode:
No abstract at ADS
Title: Astrophysics 1930-1940
Authors: Thackeray, A. D.
Bibcode: 1940Obs....63..311T
Altcode:
No abstract at ADS
Title: Convective equilibrium and solar limb darkening
Authors: Thackeray, A. D.
Bibcode: 1940MNRAS.100..614T
Altcode:
No abstract at ADS
Title: Neutral barium in the Sun?
Authors: Thackeray, A. D.
Bibcode: 1940Obs....63..160T
Altcode:
No abstract at ADS
Title: Dispersion in estimates of spectral type
Authors: Butler, H. E.; Thackeray, A. D.
Bibcode: 1940MNRAS.100..450B
Altcode:
No abstract at ADS
Title: Solar physics
Authors: Thackeray, A. D.
Bibcode: 1940RPPh....7..160T
Altcode:
No abstract at ADS
Title: The temperature scale of late-type giants and dwarfs
Authors: Thackeray, A. D.
Bibcode: 1939Obs....62..155T
Altcode:
No abstract at ADS
Title: On the intensity of Mg 5183 in K-type stars
Authors: Thackeray, A. D.
Bibcode: 1939MNRAS..99..492T
Altcode:
No abstract at ADS
Title: Wave-lengths of blended absorption lines
Authors: Thackeray, A. D.
Bibcode: 1938Obs....61..287T
Altcode:
No abstract at ADS
Title: Two solar eruptions
Authors: Dobbie, J. C.; Moss, W.; Thackeray, A. D.
Bibcode: 1938MNRAS..98..606D
Altcode:
No abstract at ADS
Title: The Excitation of Emission Lines in Late-Type Variables
Authors: Thackeray, A. D.
Bibcode: 1937ApJ....86..499T
Altcode:
Twelve bright lines observed in Me variables are attributed to resonance
excitation, chiefly by lines in the ultraviolet. In particular, Mg II
2795 and 2802 will account for Fe 4202, 4308, 3852, and Ti 4372. The
appearance of a bright line A 39o7 is attributed to excitation by
a bright K line at low levels which is masked by an upper layer of
absorption. Five other lines are attributed to intercombination lines
of Fe ii. The Mg ii lines can be readily excited by chemiluminescence
in the formation of H2, the most abundant molecule
Title: Bright lines in a non-pulsating star
Authors: Thackeray, A. D.
Bibcode: 1937Obs....60..327T
Altcode:
No abstract at ADS
Title: 1936 June 19, Wave-lengths and intensities in the flash
spectrum
Authors: Thackeray, A. D.
Bibcode: 1937MNRAS..97..672T
Altcode:
No abstract at ADS
Title: Note on incomplete Multiplets in the Spectra of Long-Period
Variables
Authors: Merrill, P. W.; Thackeray, A. D.
Bibcode: 1937PASP...49..120M
Altcode:
No abstract at ADS
Title: Anomalous multiplet intensities in late-type stars
Authors: Thackeray, A. D.
Bibcode: 1937Obs....60...45T
Altcode:
No abstract at ADS
Title: No. 580. The excitation of emission lines in late-type
variables.
Authors: Thackeray, A. D.
Bibcode: 1937CMWCI.580....1T
Altcode:
No abstract at ADS
Title: The Blending of H and Hɛ in the Spectrum of α Lyrae
Authors: Wilson, O. C.; Thackeray, A. D.
Bibcode: 1936PASP...48..329W
Altcode:
No abstract at ADS
Title: Chromospheric Emission within H and K
Authors: Thackeray, A. D.
Bibcode: 1936PASP...48..330T
Altcode:
No abstract at ADS
Title: The Excitation of Certain Emission Lines in the Spectra of
Long-Period Variable Stars
Authors: Thackeray, A. D.; Merrill, P. W.
Bibcode: 1936PASP...48..331T
Altcode:
No abstract at ADS
Title: Intensities of Blended Absorption Lines
Authors: Thackeray, A. D.
Bibcode: 1936ApJ....84..433T
Altcode:
Intensities of nine solar mukiplets, including fourteen lines
lying in IIie wings of the H and K lines, have been measured from
plates taken with the 75-foot spectrograph of the 150-foot tower
telescope. Exposures were taken at the center of the disk, at the limb,
and over a sun-spot. The lines, measured relative to the blending wing,
show a progressive weakening as the blending increases. The intensities
are roughly proportional to the intensity within the neighboring
calcium wing. The central intensities of the blended lines remain
practically constant irrespective of the blending. Rowland intensities
are shown to depend primarily on the intensity of the core of the
line. Eddinglon's theory of the formation of absorption lines depending
on the two param- eters ~ and ~ is developed for the case of two blended
lines. A similar weakening is found which agrees with that observed,
especially when a correction is applied to allow for the fact that
blended lines are formed in higher layers of the atmosphere where i~
is larger. Severely blended lines, particularly Fe 3969, show an excess
weakening which is partially accounted for by introducing the factor e,
involving collisions or electron captures. The remainder may be due
to interlocking. It is found that the blending of Fe 3969 with the
H line has little effect on the number of atoms in the upper state,
i.e., on the intensities of other related lines, except in the higher
chromospheric layers
Title: A Comparison of Sun-Spot, Limb, and Disk Spectra
Authors: Thackeray, A. D.
Bibcode: 1936PASP...48..119T
Altcode:
No abstract at ADS
Title: No. 555. Intensities of blended absorption lines.
Authors: Thackeray, A. D.
Bibcode: 1936CMWCI.555....1T
Altcode: 1936QB4.M93n555....
No abstract at ADS
Title: The long-period variables
Authors: Thackeray, A. D.
Bibcode: 1935Obs....58..285T
Altcode:
No abstract at ADS
Title: The Emission Line λ 4511 IN Late-Type Variables
Authors: Thackeray, A. D.
Bibcode: 1935ApJ....81..467T
Altcode:
The appearance in emissioii in M and S variables of the line X 4511
(previously identi- fied as the indium resonance line X 4511.31) is
suggested as due to the coincidence in wave-length of H~ (X 4101.75)
with the other In resonance line (X 4101.72). The behavior of X 4511
relative to Ho during the cycle of variation is not at variance with
the hypothesis provided either that ionization at light-maximum is
sufficient to remove most of the In atoms out of the neutral state or
that atoms in the metastable state 2p3 are more likel
Title: Chromospheric Emission in the Wings of H and K
Authors: Thackeray, A. D.
Bibcode: 1935ApJ....81..338T
Altcode:
Certain lines near the centers of the H and K Fraunhofer lines appearing
in emission near the solar limb extend abnormally far into the disk,
as noted by Evershed, in some cases reappearing in absorption at
the center. The phenomenon is explained as a lack of radiation to
be absorbed, the atoms being able to reach the upper state prior to
emission by absorption of other wave-lengths outside H and K. Two lines
are identified as due to Nd~ and Ce~, indicating that these atoms emit
and absorb mainly above the layers in which Ca~ absorption takes place
Title: Observed central intensities of the Fraunhofer lines
Authors: Thackeray, A. D.
Bibcode: 1935MNRAS..95..293T
Altcode:
No abstract at ADS
Title: No. 517. The emission line λ 4511 in late-type variables.
Authors: Thackeray, A. D.
Bibcode: 1935CMWCI.517....1T
Altcode:
No abstract at ADS
Title: No. 516. Chromospheric emission in the wings of H and K.
Authors: Thackeray, A. D.
Bibcode: 1935CMWCI.516....1T
Altcode: 1935QB4.M93n516....
No abstract at ADS
Title: Sodium and magnesium in stellar spectra
Authors: Thackeray, A. D.
Bibcode: 1934MNRAS..94..538T
Altcode:
No abstract at ADS
Title: Anomalous multiplet intensities in stellar spectra and sunspots
Authors: Thackeray, A. D.
Bibcode: 1933MNRAS..94...99T
Altcode:
No abstract at ADS
Title: The central intensities of the Fraunhofer lines
Authors: Thackeray, A. D.
Bibcode: 1933Obs....56..276T
Altcode:
No abstract at ADS
Title: The central intensities of the Fraunhofer lines
Authors: Thackeray, A. D.
Bibcode: 1933Obs....56..228T
Altcode:
No abstract at ADS