Messenger No. 11 (December 1977)
1-2 (PDF)
Variable Stars in IC 5152
ADS BibCode:
1977Msngr..11....1L
Author(s)/Affiliation(s):
Laustsen, S.; Tammann, G.
AA(Scientific Group, ESO/Geneva) AB(Scientific Group, ESO/Geneva)
Abstract:
One of the best methods to determine the distance to a (nearby) galaxy is to measure the periods and magnitudes of the so-called cepheids in the galaxy. The cepheids are variable stars and they are found by comparing photographic plates of the galaxy from different nights. Drs. Svend Laustsen and Gustav Tammann from the Scientific Group at ESO/Geneva have just analysed such plates of the IC 5152 galaxy:
2-3 (PDF)
The Satellites of Uranus and Neptune: A New Astrometrie Programme
ADS BibCode:
1977Msngr..11....2R
Author(s)/Affiliation(s):
Ratier, G.; Calame, O.
AA(Pic-du-Midi Observatory in the French Pyrenees) AB(Pic-du-Midi Observatory in the French Pyrenees)
Abstract:
Observations are now being obtained at La Silla of the outer planets Neptune and Uranus. In order to determine exact positions of the satellites of these two giant planets, Drs. G. Ratier and O. Calame of the Pic-du-Midi Observatory in the French Pyrenees have recently used the ESO 1.5 m telescope. They give some preliminary information about their important programme:
3-4 (PDF)
The X-ray Cluster of Galaxies Klemola 44
ADS BibCode:
1977Msngr..11....3D
Author(s)/Affiliation(s):
Danks, Anthony C.
AA(ESO, Chile)
Abstract:
On October 17, 1977, three astronomers sat together at lunch on La Silla. One, Dr. Massimo Tarenghi - newcomer to the Scientific Group in Geneva - had just returned from the Interamerican Observatory on Gerro Tolo1o. Another, Dr. Anthony G. Danks, recently joined ESO/Ghile, and the third was the editor of this journal. By chance, Dr. Danks showedsome plates of the cluster of galaxies Klemola 44 which he had obtained a few nights before with the 3.6 m telescope. Dr. Tarenghi told that he had observed the same galaxies spectroscopically the night before at Tololo. An intense exchange of information resulted. The editor smiled happily and then made the inevitable suggestion ... So here is the essence of that discussion, summarized by Dr. Danks.
References:
Ghincarini G., Tarenghi M., Bettis C., 1977, Ap. J. (to be published).
; Maccacaro T., Cooke, B. A., Ward M. J., Penston M. V., Hayes R. F., 1977, M.N.R.A.S. 180, 465.
; Solinger A. B., Tucker W. M., 1972, Ap. J. 175, L107.
3-3 (PDF)
Optical Telescopes of the Future
ADS BibCode:
1977Msngr..11....3.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
The Organizing Committee informs us that the preparations for this ESO conference are proceeding weil. It will take place at CERN, Geneva, on December 12-15, 1977. Prospective participants who have notyet announced their arrival are requested to contact Dr. R. N. Wilson, ESO c/o CERN, CH-1211 Geneva 23, Switzerland, as soon as possible.
4-4 (PDF)
Reference Positions of Southern Stars: PERTH70
ADS BibCode:
1977Msngr..11....4H
Author(s)/Affiliation(s):
Hog, E.
AA(ESO)
Abstract:
A new catalogue, Perth70, containing one star per square degree has appeared: E. Hog and J. von der Heide, 1976, Abhandl. aus der Hamburger Sternwarte IX, and also available on magnetic tape from the Strasbourg Data Centre. The catalogue was observed about 1970 with a mean error 0".17 and contains approximate proper motions giving positional accuracy of ± 0".3 at the epoch 1980. The accuracy of the widely used SAO catalogue is about ± 1".
5-7 (PDF)
A Search for Beta Cephei Stars in the Southern Hemisphere
ADS BibCode:
1977Msngr..11....5S
Author(s)/Affiliation(s):
Sterken, C.; Jerzykiewicz, M.
AA(Landessternwarte Heidelberg-Königstuhl, FRG) AB(University of Wroclaw, Poland)
Abstract:
The present article is another illustration of new, exciting work in the southern hemisphere which is still largely unexplored when compared to the northern. Drs. Christiaan Sterken and Mikolaj Jerzykiewicz have during the past years been looking for new, relatively bright variable stars of the ß Cephei type south of -20°. The observations were made by Dr. Sterken, who was formerly with ESO in Chile, and who will spend another year at the Landessternwarte Heidelberg-Königstuhl, FRG, before he returns to his native Belgium. Dr. Jerzykiewicz made the reductions with the ODRA 1204 computer of the University of Wroclaw, Poland.
7-8 (PDF)
Vertical Extinction on La Silla
ADS BibCode:
1977Msngr..11....7T
Author(s)/Affiliation(s):
Tüg, H.
AA(Astronomical Institute of the Ruhr University, Bochum, FRG)
Abstract:
Among the many tactors that determine the quality ot an observatory site, two are crucial. These are the seeing (how much the light trom a ce/estial object is spread out during the passage through the Earth's atmosphere) and the extinction (how much the light is weakened during the passage). It has long been known that La Silla is among the best sites in the world what concerns seeing but it is only recently that a major study has revealed that the La Silla extinction is very small on good nights. Dr. H. Tüg trom the Astronomical Institute ot the Ruhr University in Bochum, FRG, spent several months on La Silla in 1974-76 with his "black-body" platinum oven which will still be remembered as the "new star" next to the water tanks, where the Swiss telescope is now situated. As a result ot his work, we can now give quantitative tigures tor the extinction at ESO.
8-9 (PDF)
High-dispersion Investigation of the Nucleus of NGC 253
ADS BibCode:
1977Msngr..11....8U
Author(s)/Affiliation(s):
Ulrich, M.-H.
AA(Observatoire de Paris, France)
Abstract:
Dr. Marie-Helene Ulrich is a well-known authority on emission-line galaxies and comes originally trom the Observatoire de Paris, France. She has worked tor a long period in the USA, at the University ot Texas, Austin, and recently came back to Europe to join the ESO Scientific Group in Geneva. She here discusses the nearby galaxy NGC 253 and shows how optical, intrared and radio observations come together in a modelot this very interesting object.
10-11 (PDF)
Photometry of OB Stars in Carina
ADS BibCode:
1977Msngr..11...10W
Author(s)/Affiliation(s):
Wramdemark, S.
AA(Lund Observatory, Sweden)
Abstract:
The spiral structure of our Galaxy has for many years been mapped by radio observations of the hydrogen 21-cm line. Similar optical observations are severely influenced by the absorbing interstellar matter in the plane of the Milky Way and we know comparatively little about the distribution of stars beyond some kiloparsecs. However, investigations of faint (and therefore mainly distant) hot OB stars in the direction of the Carina spiral arm now give a more accurate picture of this feature. Dr. Stig Wramdemark of the Lund Observatory in Sweden last year published the results of earlier observations at La Silla. He here gives an up-to-date summary of his latest observations:
10-10 (PDF)
OH/IR Sources as an Example of a Successful Simultaneous Radio and Infrared Programme
ADS BibCode:
1977Msngr..11...10K
Author(s)/Affiliation(s):
Kreysa, E.; Schultz, G. V.; Sherwood, W.A.; Winnberg, A.
AA(Max-Planck-Institut für Radioastronomie (MPIfR), Bonn) AB(Max-Planck-Institut für Radioastronomie (MPIfR), Bonn) AC(Max-Planck-Institut für Radioastronomie (MPIfR), Bonn) AD(Max-Planck-Institut für Radioastronomie (MPIfR), Bonn)
Abstract:
Drs. E. Kreysa, G. V. Schultz, W.A. Sherwood and A. Winnberg from the Max-Planck-Institut für Radioastronomie (MPIfR) in Bonn have during the last two years simultaneously observed OH/IR sources atthe 100 m Effelsberg and the 1 m ESO telescopes. G. V. Schultz reports about the results which open the door to further exciting investigations:
11-12 (PDF)
Three New Comets
ADS BibCode:
1977Msngr..11...11.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
The ESO 1 m Schmidt telescope has been involved in the discovery of three new comets since the last issue of the Messenger. One, P/Comet Schuster (1977o) is a "real" ESO comet; the two others, P/Comet Chernykh (1977l) and P/Comet Sanguin (1977p) were confirmed with this telescope, after they first had been sighted in USSR and Argentina, respectively.
12-14 (PDF)
Those Troublesome Wolf-Rayet Stars
ADS BibCode:
1977Msngr..11...12L
Author(s)/Affiliation(s):
Lundström, I.; Stenholm, B.
AA(Lund Observatory) AB(Lund Observatory)
Abstract:
The Wolf-Rayet stars are among the more spectacular in our Galaxy. Not only are they some of the hottest and most massive stars known, but they also stand out as strong emission-line objects. With the aim of improving their usefulness for the study of the structure of the Galaxy, two Swedish astronomers, Drs. Ingemar Lundström and Björn Stenholm from the Lund Observatory, have initiated a study of the absolute magnitudes of WolfRayet stars. Dr. Stenholm writes about the observations at ESO and how it now appears that most (if not all) Wolf-Rayet stars are in fact double stars:
14-15 (PDF)
Where Stars are Born
ADS BibCode:
1977Msngr..11...14B
Author(s)/Affiliation(s):
Bernes, C.
AA(Stockholm Observatory)
Abstract:
Dr. Claes Bernes of the Stockholm Observatory has compiled a new catalogue of bright nebulosities in dense dust clouds. He found 160 such objects when searching on the Palomar and ESO (B) atlases. Many of these objects are stellar birth-centres and they will soon be studied by radio and infrared observations. Dr. Bernes reports:
15-16 (PDF)
Accurate Spectrophotometry of Early-type Spectrum Variable Stars
ADS BibCode:
1977Msngr..11...15P
Author(s)/Affiliation(s):
Pedersen, H.
AA(Danish astronomer, Astronomical Institute of the Arhus University)
Abstract:
A Danish astronomer, Dr. Holger Pedersen trom the Astronomical Institute ot the Arhus University, has recently used a novel instrument, ELlS, to measure the intensity (equivalent width) ot the He I 4026 line in earlytype stars. The accuracy is impressive and Dr. Pedersen has tound several new spectrum variable stars. The observations were carried out at the ESO and CARSO observatories and are here summarized by Dr. Pedersen:
16-18 (PDF)
Optical Radiation Found in the Radio Lobes of Double Radio Galaxies
ADS BibCode:
1977Msngr..11...16C
Author(s)/Affiliation(s):
Grane, Philippe; Saslaw, William G.
AA(ESO Scientific Group, Geneva) AB(Institute of Astronomy, Cambridge, U.K., AND University of Virginia, Charlottesville, USA)
Abstract:
Pushing the largest telescopes to their faintest limits is certainly not easy, but often extremely rewarding. The discovery of optical objects associated with powerful double radio sources (for which only the central galaxy was known before) will undoubtedly have a great impact on the study of the physics of radio galaxies. Two of the codiscoverers, Dr. Philippe G. Grane of the ESO Scientific Group in Geneva (formerly Princeton University) and Dr. William G. Saslaw, Institute of Astronomy, Gambridge, U.K., and University of Virginia, Gharlottesville, USA, here review the new, fascinating discoveries- for the first time outside the professional journals.
18-20 (PDF)
Peculiar A-type Stars at ESO
ADS BibCode:
1977Msngr..11...18M
Author(s)/Affiliation(s):
Maitzen, H.-M.; Weiss, W. W.
AA(Figl-Observatorium für Astrophysik, Vienna) AB(Figl-Observatorium für Astrophysik, Vienna)
Abstract:
The study of peculiar Astars is a fascinating chapter of modern astronomy. It combines measurements of light variability, variable spectrallines and magnetic fields. This review article by two Austrian astronomers, Ors. H.-Michael Maitzen and Werner W. Weiss from the Figl-Observatorium für Astrophysik (Vienna) discusses not only the observations, but also the attempts to explain theoretically the Ap phenomenon. It is probably true to say that the stellar models still are somewhat uncertain, but new and improved observational methods continuously refine the interpretation. The authors are frequent observers on La Silla.
20-20 (PDF)
Planetary Nebula NGC 3132
ADS BibCode:
1977Msngr..11Q..20.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
Planetary Nebula NGC 3132
20-20 (PDF)
The Cluster of Galaxies STR 2232-380
ADS BibCode:
1977Msngr..11R..20.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
The Cluster of Galaxies STR 2232-380
20-20 (PDF)
The Sagittarius Dwarf Irregular Galaxy (SagDIG)
ADS BibCode:
1977Msngr..11S..20.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
The Sagittarius Dwarf Irregular Galaxy (SagDIG)
21-21 (PDF)
Printing High-contrast Astronomical Plates
ADS BibCode:
1977Msngr..11...21.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
Most photographic emulsions currently used in astronomy are rather contrasty, for instance Illa-J and Illa-F (formerly 127-04). This is a great advantage for reaching faint objects, but it turns into a problem when pri nts are made from the original plate. Photographic paper can only hold a limited range of densities and the prints therefore tend to beCome very unsatisfactory; either the high densities show no detail or the faint structures are lost in the background.
22-23 (PDF)
The Coude Echelle Spectrometer
ADS BibCode:
1977Msngr..11...22.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
The coude echelle spectrometer of the ESO 3.6 m telescope is designed to reach a very high resolution (typically higher than 100,000) with a good photometric accuracy. The spectrometer will work in two possible modes. The first is a scanning mode where an alternatively rotatable echelle 200 x 400 mm moves the spectrum with regard to a fixed slit, the photon flux being detected by a high quantum efficiency cooled photomultiplier. In order to get a higher accuracy, the beam passes, in fact, twice on the grating. The dispersion is doubled and the beam focused on an intermediate slit, the instrumental profile, i. e. the system response to a perfect spectral line being made as pure as possible. Any wings and ghosts given by the grating or the optics are removed.
23-23 (PDF)
Algunos Resumenes
ADS BibCode:
1977Msngr..11Q..23.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
Extincion en La Silla; Estrellas variables en IC 5152
23-23 (PDF)
Further Observations 01 ESO 113-IG45
ADS BibCode:
1977Msngr..11R..23.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
Further Observations 01 ESO 113-IG45
23-23 (PDF)
Personnel Movements
24-24 (PDF)
A Quasar in a Galaxy!
ADS BibCode:
1977Msngr..11...24.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
Astronomers have observed quasars since 1963. More than 600 are now catalogued, but we still know relatively little about them. Most scientists believe that they are at "cosmological" distances, i. e. that their redshifts reflect the expansion of the universe, and that they therefore are very distant and very luminous objects.