Messenger No. 28 (June 1982)

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1-3 (PDF)
B. E. Westerlund
The ESO Observing Programmes Committee

ADS BibCode:
1982Msngr..28....1W
Author(s)/Affiliation(s):
Westerlund, B. E.
AA(Astronomical Observatory, Uppsala, Chairman of the OPC)
Abstract:
Since 1978 the ESO Observing Programmes Committee (OPC) has "the function to inspect and rank the proposals made for observing programmes at La Silla, and thereby to advise the Director General on the distribution of observing time". The members (one from each member country) and their alternates are nominated by the respective national committees for five-year terms (not immediately renewable). The terms are staggered so that each year one or two persons are replaced. The Chairman is appointed annually by the Council. He is invited to attend Council meetings and to report to its members.
1-1 (PDF)
ESO
ITALY, Member of ESO

ADS BibCode:
1982Msngr..28....1.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
On May 24, 1982, the Italian Ambassador in Paris deposited the instrument of accession with the Ministry of Foreign Affairs of the French Republic, as foreseen by Art. 13 of the ESO Convention. With this act Italy has become a member of ESO.
3-3 (PDF)
ESO
The Proceedings of ESO Symposium Evolution in the Universe

ADS BibCode:
1982Msngr..28....3.
Author(s)/Affiliation(s):
ESO
AA(ESO)
4-7 (PDF)
P. E. Nissen
Age and metal abundance of a globular cluster, as derived from Stromgren photometry

ADS BibCode:
1982Msngr..28....4N
Author(s)/Affiliation(s):
Nissen, P. E.
AA(Aarhus Universitet, Aarhus, Denmark)
Abstract:
The results of a photoelectric uvby-beta survey of turnoff stars in globular clusters to improve the accuracy of the lower limits to estimates of the age of the Universe are reported. Emphasis is placed on observations of stars in the 8-11 mag range in the second-nearest globular cluster, NGC 6397. Only objects in the outer regions were studied, due to the density of the stars in the center of the cluster. A color excess within 0.02 of 0.14 was found, along with a metal abundance within 0.2 of -1.6, with a Z of 0.0004. The age of NGC 6397 is calculated to have a lower limit of 16 billion yr., which agrees with a Hubble constant of 52 if the density parameter is less than 0.2.
References:
Aaronson, M., Mould, J., Huehra, J., Sullivan, W.T., Sehommer, RA,Sothun, G.D.: 1980, Astrophys. J. 239, 12.
Aleaino, G., Liller, W.: 1980, Astron. J. 85, 680.
Carney, SW.: 1979, Astrophys. J. 233,211.
Crawford, D.L.: 1975, Astron. J. 80, 955.
Crawford, D.L., Mandwewala, N.: 1976, PAS.P. 88,917.
Hejlesen, P.M.: 1980, Astron. Astrophys. Suppl. 39,347.
Nissen, P.E.: 1981, Astron. Astrophys. 97, 145.
Sandage, A., Tammann, GA: 1981, ESO Sei. Preprint No. 174.
7-8 (PDF)
ESO
Second ESO Infrared Workshop

ADS BibCode:
1982Msngr..28....7.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
About 70 external participants in addition to ESO staff met from 20th-23rd April 1982 to discuss a variety 01 topics ranging lrom the infrared work going on at major ground-based observatories to proposals lor luture space missions. Although mainly devoted to technical aspects, the rapid progress in instrumentation and lacilities made in recent years was best demonslrated by Ihe sampie of aslronomical resulls oblained al Calar Allo, CFHT, ESO, TIRGO, UKIRT and wilh ai rcraft and balloon-borne lelescopes which were reviewed by some of Ihe inviled speakers. The major Irend in future instrumentation was evidenl from Ihe large number of presentalions on array deteclors and Iheir applicalion in infrared imaging, speclroscopy and speckle inlerferomelry. An impressive illustration that these devices are already beginning 10 revolutionize observational possibilities came in Ihe form of 20 "pholographs" al 10 ~m shown of such old infrared favouriles as the BN/KL complex in the Orion Nebula and NGC 7027
8-9 (PDF)
C. Fehrenbach et al.
Study of the Large Magellanic Cloud with the Fehrenbach Objective Prism

ADS BibCode:
1982Msngr..28....8F
Author(s)/Affiliation(s):
Fehrenbach, C.; Duflot, M.; Burnage, R.
AA(the radial velocities staff of the Marseille and HauteProvence Observataries) AB(the radial velocities staff of the Marseille and HauteProvence Observataries) AC(the radial velocities staff of the Marseille and HauteProvence Observataries)
Abstract:
The 40 cm Objeclive-Prism (GPO or Grand Prism Objeclif in French), now at La Silla, had first been used in the Southern Hemisphere, al Zeekoegat, in Soulh Africa. ESO, then looking for a site for its observatory, had accepted its inslallalion on one of the tested siles. It is Ch. Fehrenbach who, as early as in 1958, thought that the deteclion of the members of Ihe Large Magellanic Cloud (LMC) from their radial velocity (RV) would be weil suited to the GPO then operating at the Haute-Provence Observatory. Indeed, because of its velocity relative to the Galaxy and of its galactic longitude of about 280°, the stars of the LMC have a RV of the order of 250 km S-1, weil outside the range of RV of the galactic stars.
References:
M. Duflot, A. Duflot and Ch. Fehrenbach: 1964, Communication ESO 3.
Ch. Fehrenbach, M. Duflot and A. Duflot: 1965, Communication ESO 6.
Ch. Fehrenbach and M. Duflot: 1972, Astronomyand Astrophysics, 21,321.
G. de Vaucouleurs and K.C. Freeman: 1972, Vistas in Astronomy 14,163.
Ch. Fehrenbach, M. Duflot and A. Acker: 1976, Astronomy and Astrophysics Suppl. 24,379.
Ch. Fehrenbach, M. Duflot and A. Acker: 1978, Astronomy and Astrophysics Suppl. 33, 115.
9-11 (PDF)
P. D. Atherton et al.
TAURUS - The imaging Fabry-Perot at La Silla

ADS BibCode:
1982Msngr..28....9A
Author(s)/Affiliation(s):
Atherton, P. D.; Danziger, I. J.; Fosbury, R. A. E.; Taylor, K.
AA(Imperial College of Science and Technology, London, England), AB(European Southern Observatory, Garching, West Germany), AC(Royal Greenwich Observatory, Herstmonceux, Sussex, England), AD(Anglo-Australian Observatory, Sydney, Australia)
Abstract:
Design features and performance parameters of the TAURUS scanning Fabry-Perot system used in concert with an image photon counting system (IPCS) at La Silla are described. The TAURUS device was installed at the Cassegrain focus of a 3.6 m telescope, and will be used in studies where velocity data are needed as a function of the position of extended objects. The Fabry-Perot image is scanned by the IPCS, with each pixel mapping out a spectral line profile within limits of the blocking interference filter. A profile can therefore be constructed for each part of the object under examination. The angle dependence of the light passing through the grating allows analysis of individual wavelengths, which can be summed to yield equivalent narrow band interference pictures. Observations of active galaxies, SNR, and the velocity structures of emission line features are indicated.
12-13 (PDF)
C. Sterken, N. Vogt
Radial Velocity Observations with the 36-INCH Telescope at Cerro-San Santiago Chile

ADS BibCode:
1982Msngr..28...12S
Author(s)/Affiliation(s):
Sterken, C.; Vogt, N.
AA(Astrophysical Institute, Brussels) AB(Universitäts-Sternwarte, München)
Abstract:
Around the end of last eentury there was an urgent need for systematie determinations of radial veloeities of southern stars. WW. Campbell at Liek Observatory therefore organized an astronomieai expedition with the aim to install an observatory with a radial veloeity teleseope in Chile. 0.0. Mills provided the funds to make a repliea of the Liek Observatory 36" teleseope, and donated the dome and expedition eosts. A 850 m high hili in a ehain near Santiago was seleeted as observatory site, mainly for the adequate loeation and the presenee of logistie support from the town of Santiago. The expedition was initially planned for three years (1902-1905), but the interesting results prompted the initiators to keep the station funetioning until1928. The results were published in the famous radial veloeity eatalogues in the Liek Observatory Bulletins.
13-14 (PDF)
M. P. Veron et al.
A New and Interesting SEYFERT-2 Galaxy - NGC5728

ADS BibCode:
1982Msngr..28...13V
Author(s)/Affiliation(s):
Veron, M. P.; Veron, P.; Tarenghi, M.; Grosbol, P.
AA(ESO) AB(ESO) AC(ESO) AD(ESO)
Abstract:
NGC 5728 is an SBb galaxy; its galactocentric radial velocity is 2,710 km S-1; with Ho = 50 km S-1 Mpc-1, its distance is 54 Mpc and 1" = 262 pc. The central structure of NGC 5728 is curiously asymmetric; a high luminosity nucleus sits within a high-surface brightness ring (dimensions 7"5 x 10"0 or 2.0 x 2.6 kpc); but the nucleus is displaced from the centre towards the east (Sandage and Brucato 1979, Astronomica/ Journa/84, 472; Rubin 1980, Astrophysica/ Journa/238, 808).
14-14 (PDF)
ESO
List of Preprints Published at ESO Scientific Group

ADS BibCode:
1982Msngr..28...14.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
191. R. M. West and A. Kruszewski: Distant Clusters 01 Galaxies in the Southern Hemisphere. A Status Report. Irish Astronomical Journal. March 1982.
15-18 (PDF)
F. van Leeuwen, P. Alphenaar
Variable K-type stars in the Pleiades cluster

ADS BibCode:
1982Msngr..28...15V
Author(s)/Affiliation(s):
van Leeuwen, F.; Alphenaar, P.
AA(Royal Greenwich Observatory, Herstmonceux, Sussex, England), AB(Leiden, Rijksuniversiteit, Sterrewacht, Leiden, Netherlands)
Abstract:
Photometric observations of three late G and 16 early K stars in the Pleiades cluster in 1980-81 are reported. Light curves similar to BY Dra stars were observed and sorted by period. Spectroscopic data were also obtained for the stars Hz 1883 and Hz 3163, and rotational velocities of 150 and 75 km/sec, respectively, were detected, high for K-stars. Observed variations in the photometric and rotational periods are discussed in terms of rotational modulation signaled by inhomogeneous luminosity distribution over the stellar surface. Deformation of the stars into triaxial ellipsoids due to their fast rotation could produce light curves with two maxima and minima, which were recorded. Further theoretical work on the model for nonaxial symmetry for fast rotating stars is indicated, particularly in the case of binaries.
18-19 (PDF)
ESO
A New Large Telescope for German Astronomers

ADS BibCode:
1982Msngr..28...18.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
On 9 March 1982 the largest telescope hitherto built in Germany was presented by Carl Zeiss to the public. It is the 3.5 m telescope of the Max-Planck Institute for Astronomy, which will be the center piece of the German-Spanish Observatory at Calar Alto in Southern Spain.
19-21 (PDF)
C. Madsen
Photographic Image Manipulation

ADS BibCode:
1982Msngr..28...19M
Author(s)/Affiliation(s):
Madsen, C.
AA(ESO)
Abstract:
The Messenger No. 25 contained a short, general description of the non-atlas work being done in the Sky Atlas Laboratory. Briefly mentioned in the article were contrast manipulating methods ranging from masking-to reduce the contrast of a picture--to contrast enhancing methods used to obtain printable negatives (or positives). Here the procedure, the advantages and the problems connected with masking and image amplification, will be described in some detail.
References:
Malin, D. F., AAS Photo-Bul/etin No. 16, 1977.
Malin, D. F., Anglo-Australian Observatory Preprint, 1981.
Saxby, R. and Dumoulin, S., The Messenger, December 1977.
21-22 (PDF)
ESO
ESO Workshop on Groundbased Observations of Halley's Comet

ADS BibCode:
1982Msngr..28...21.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
The ESO Workshop on "Ground-based Observations of Halley's Comet" took place at the Institut d'Astrophysique de Paris on 29 and 30 April 1982. The aim of the workshop was to encourage cooperation between theoreticians and observers to get the best from all available observing facilities during the next apparition of comet Halley in 1985-1986 and especially of the optical telescopes on La Silla.
22-25 (PDF)
Y. Andrillat
Near infrared observations of O stars

ADS BibCode:
1982Msngr..28...22A
Author(s)/Affiliation(s):
Andrillat, Y.
AA(Haute-Provence, Observatoire, Saint-Michel-l'Observatoire, Alpes-de-Haute-Provence, France)
Abstract:
Observations of O stars using a reticon (Si detector) to examine emission features in the near-IR are described. Particular note is made of studies of the He and C lines in terms of formation processes. The results of a survey of the He I 10830 A line in 67 northern O stars are outlined, with mention made of a correlation between the mass loss rate and the intensity of the He I band. No 10830 emission was seen in the four very hot supergiants surveyed. Increases in the 10830 A emission feature are suggested to be caused by an envelope comprising a large mass of material surrounding a core at temperatures from 30,000-40,000 K. The reticon permitted accurate intensity measurements, with allowances made for atmospheric absorption. Other line excesses were inventoried for the 67 stars, and the presence of C III gamma gamma 9701-9715 lines is discussed. A link is indicated between the late-type O-stars and transition Wolf-Rayet stars, with both types losing mass through a stellar wind effect.
22-22 (PDF)
ESO
Personnel Movements

ADS BibCode:
1982Msngr..28Q..22.
Author(s)/Affiliation(s):
ESO
AA(ESO)
22-22 (PDF)
ESO
The ESO / Uppsala Survey of the ESO / Atlas

ADS BibCode:
1982Msngr..28R..22.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
A systematic search for certain objects (NGC + IC galaxies, all galaxies with a diameter larger than about 1.0 arcmin, all disturbed galaxies, all star clusters in the Budapest Catalogue, and aillisted planetary nebulae) has been carried out by means of the ESO(B) Atlas, covering the southern sky from -90 to -17.5 degrees. A total of 18,438 objects is listed; of these, about 60% for the first time. Magnitudes and radial velocities are also given for a total of 2,102 galaxies.
25-28 (PDF)
D. Koester
White dwarfs - The dying stars

ADS BibCode:
1982Msngr..28...25K
Author(s)/Affiliation(s):
Koester, D.
AA(Kiel, Neue Universitaet, Institut fuer theoretische Physik und Sternwarte, Kiel, West Germany)
Abstract:
Observations and characteristics of white dwarf stars are described, with an emphasis on programs carried out at La Silla. White dwarfs are the end product of 90% of observable stars, with some exhibiting magnetic fields of up to 100 million gauss, and others associated with X ray emitting binaries. Having masses of 0.5 sun contained in a body the size of the earth, white dwarf stars do not feature nuclear reactions, but do possess gravitational energies and thermal reactions until totally cooled. Free electron pressure balancing gravitational forces prevents transition to neutron star status or collapse into a black hole. Estimation techniques for determining the critical star mass necessary for white dwarf formation are discussed. Observational programs to identify white dwarfs by Balmer hydrogen lines spread to 50 A width are noted, particularly the necessity of long integration times for photometric imagery when scanning the faint objects. The expected absolute magnitude of white dwarf stars has been calculated as about 20.
28-29 (PDF)
R. Louise, E. Maurice
High spectral resolution observations of forbidden S II lines in the planetary nebula IC 418 at the CES spectrograph

ADS BibCode:
1982Msngr..28...28L
Author(s)/Affiliation(s):
Louise, R.; Maurice, E.
AA(Marseille, Observatoire, Marseille, France), AB(European Southern Observatory, Garching, West Germany)
Abstract:
Preliminary observations of [S 11] lines at 6717 and 6731 Aof the planetary nebula IC 418 are presented. Observations are made with the ESO Coude Echelle Spectrometer (CES) and the Coude Auxiliary Telescope (CAT); the resolving power is 105, corresponding to a dispersion of 1.87 Amm-1 or a spectral resolution of 0.067 A. Both [S 11] lines present two weil separated components corresponding to a shell expanding at the velocity of 30.3 km S-1. It is shown that density and thickness of this shell, as observed on the line of sight at two diametrically opposite points, are similar, whereas the S+ concentration suggests a non-symmetricai ionization structure.
References:
Aller, L. H.: 1956, Gaseaus Nebulae, London, Chapman (Hall) p. 252.
Canlo, J., Elliol, K. H., Meaburn, J., Theckas, A. C.: 1980, Mon. Not. R. Astr. SOG. 193,911.
Czyzak, S. J., Aller, L. H.: 1979, Mon. Not. R. Astr. SOG. 188,229.
Enard, D.: 1981, The Messenger No. 26 (December 1981), 22.
Oslerbrock, D. E.: 1970, Astrophys. J. 159, 823.
Pradhan, A. K.: 1978, Mon. Not. R. Astr. SOG. 183, 89P.
Reay, N. K., Worswick, S. P.: 1979, Astron. Astrophys. 72,31.
Wilson, O. C.: 1950, Astrophys. J. 111,279.
Wilson, O. C.: 1953, Astrophys. J. 117, 264.
Wilson, O. C., Aller, L. H.: 1951, Astrophys. J. 114,421.
29-30 (PDF)
S. Dodorico, A. F. M. Moorwood
The fate of dust grains in a shock wave originated by a SN explosion

ADS BibCode:
1982Msngr..28...29D
Author(s)/Affiliation(s):
Dodorico, S.; Moorwood, A. F. M.
AA(European Southern Observatory, Garching, West Germany), AB(European Southern Observatory, Garching, West Germany)
Abstract:
The results of a 10 and 12 micron IR survey of three supernova remnants (SNR) in the LMC in November 1982 are reported. The studies were undertaken to provide evidence for determining if in fact dust grains are present in SNR and are heated by passage of the supernova blast waves. The objects examined, N49, N63A, and N132D, are X ray sources, and have expansion velocities of 100-200 km/sec. A grain temperature of 80-300 K was calculated, but associated with a total grain mass too large to be correct. A flux of 50 mJy, however, does indicate a mass of 0.002 solar mass in a gas/dust ratio of 1000, which is an acceptable figure.
30-33 (PDF)
P. Ahlin, A. Sundman
A Long Period Eclipsing Binary Project - Five Years of Observations at ESO

ADS BibCode:
1982Msngr..28...30A
Author(s)/Affiliation(s):
Ahlin, P.; Sundman, A.
AA(Stockholms Observatorium) AB(Stockholms Observatorium)
Abstract:
The star HO 161387 first caught our eyes when we were reading an article on ~ Aurigae stars by K. O. Wright in Vistas in Astronomy No. 12. This was some 8 or 9 years ago. Aurigae stars are eclipsing binaries formed by a cool supergiant K star and a very much smaller and holter mainsequence (more or less normal) B star. Out of eclipse the B star dominates the blue spectral region, but a pure K-type spectrum is found in eclipse. The drastic spectral changes lor HO 161387 can be seen in Fig 1c and 1d. Periods for these binaries are in the range of 2 to 10 years. The general benefit 01 ~ Aurigae star studies is the possibility of direct determination 01 physical parameters of the components such as masses and radii. In practice, what one does observe is the change in radial velocity of the stars as they orbit around their common centre 01 gravity and the change in magnitude as the light from the B star is eclipsed by the K supergiant. There is also the possibility of studying the structure of the atmosphere of a K supergiant manifested by spectral changes occurring as the point light of the B star shines through the outer parts of the K star c1ose to the total eclipse. Besides Aurigae itsell only the stars 31 and 32 Cygni have been studied in greater detail.
33-34 (PDF)
R. Barbier
The Photometric Reduction Service on La-Silla

ADS BibCode:
1982Msngr..28...33B
Author(s)/Affiliation(s):
Barbier, R.
AA(ESO-La Silla)
Abstract:
Observing with a photometrie telescope needs interaction from the astronomer: he is the one who can exercise the soundest judgement on how to proceed with his programme. He will for instance decide to change instrumental parameters such as integration time, sequence of filters, diaphragm ..., or to reobserve a given object which was not measured accurately enough or which shows interesting variations.
34-35 (PDF)
J. Penafiel
Fire Brigade and Rescue Squad

ADS BibCode:
1982Msngr..28...34P
Author(s)/Affiliation(s):
Penafiel, J.
ESO
Abstract:
An emergency is defined as an unforeseen combination of circumstances which can lead to danger of human life and to damage of property, requiring immediate action. In order to be prepared for this "immediate action", two groups were formed by the safety engineer at La Silla: a fire brigade and a rescue squad. Whilst the tasks of the former group may be clear to everybody, the latter one's aim is to intervene in the case of technical accidents, e. g. a car accident.
35-36 (PDF)
J. Penafiel
Cuerpo de Bomberos y Grupo de Rescate

ADS BibCode:
1982Msngr..28...35P
Author(s)/Affiliation(s):
Penafiel, J.
AA(ESO)
Abstract:
Una emergencia es una combinacion imprevista de circunstancias que podrian dar por resultado peligro para la vida humana 0 dario a la propiedad, que requiere una accion inmediata.
35-35 (PDF)
ESO
Italia, pais miembro de la ESO

ADS BibCode:
1982Msngr..28...35.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
Con lecha 24 de Mayo de 1982 el embajador de Italia en Paris hizo entrega dei documento de afiliacion en el Ministerio de Relaciones Exteriores Frances, acto requerido segun el art. 13 de la Convencion de ESO, que atestigua la afiliacion de Italia como pais miembro.