Messenger No. 22 (December 1980)

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1-4 (PDF)
J. Audouze et al.
The Dwarf Blue Compact Galaxies

ADS BibCode:
1980Msngr..22....1A
Author(s)/Affiliation(s):
Audouze, J.; Dennefeld, M.; Kunth, D.
AA(Institut d'Astrophysique du CNRS, Paris) AB(Institut d'Astrophysique du CNRS, Paris) AC(Institut d'Astrophysique du CNRS, Paris)
Abstract:
Among the very different types of galaxies which can be analysed, the dwarf blue compact galaxies have been first recognized as a class by Sargent and Searle (1970: Astrophysical Journal. 162,455). Some important properties let them be priceless tools to enlighten many basic astrophysical problems, such as the primordial nucleosynthesis and cosmology, the chemical evolution of galaxies and the theories of star formation. These galaxies are generally dwarf irregular objects with low mass but the bulk of the luminosity is in the blue range. Their spectra look strikingly like those of a giant H1I region. That is why they have been called extragalactic HII region by Sargent and Searle. From their emission lines it is rather straightforward to derive their He, N, 0, Ne and possibly S conten!. Some of these abundances, including some of our own results obtained at La Silla, are summarized in Section 3.
3-3 (PDF)
ESO
Tentative Time-table of Council Sessions and Committee Meetings in 1981

ADS BibCode:
1980Msngr..22....3.
Author(s)/Affiliation(s):
ESO
AA(ESO)
4-4 (PDF)
ESO
Personnel Movements

ADS BibCode:
1980Msngr..22....4.
Author(s)/Affiliation(s):
ESO
AA(ESO)
5-7 (PDF)
C. I. Lagerkvist
Physical Studies of Asteroids - an Observing Program at ESO

ADS BibCode:
1980Msngr..22....5L
Author(s)/Affiliation(s):
Lagerkvist, C. I.
AA(Astronomical Observatory, Uppsala)
Abstract:
The majority of the asteroids are small and tiny bodies orbiting the sun between Mars and Jupiter. One can estimate the total number of asteroids with diameters greater than 1 km to be more than 700,000. Compared to the major planets, the thermal and geological evolution of the asteroids has been modest. Observing asteroids gives us thus not only clues to the origin and evolution of the asteroids, but also to that of the planetary system.
7-10 (PDF)
H. E. Schuster
Mapping the Southern Sky with the ESO 1-METER Schmidt Telescope

ADS BibCode:
1980Msngr..22....7S
Author(s)/Affiliation(s):
Schuster, H. E.
AA(ESO)
Abstract:
To any astronomer, professional or amateur, the Palomar Observatory Sky Survey (shortly POSS) is a well-known and usefultool. The whole northern sky is photographed' and prints from these photographs are available in the libraries of nearly all important observatories and astronomical institutes in the world.
7-7 (PDF)
ESO
Announcement of an ESO/ESA Workshop on 'Optical Jets in Galaxies'

ADS BibCode:
1980Msngr..22....7.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
Second ESO/ESA Workshop on the Use of the Space Telescope and Coordinated Ground-based Research
10-12 (PDF)
H. Drechsel et al.
Simultaneous Optical and Satellite Observations Provide New Understanding of a Famous Nova

ADS BibCode:
1980Msngr..22...10D
Author(s)/Affiliation(s):
Drechsel, H.; Rahe, J.; Holm, A.; Krautter, J.
AA(Remeis-Observatory Bamberg) AB(NASA-Goddard Space Flight Center, Greenbe/t, MD, USA) AC(Computer Seiences Corporation, Silver Spring, MD, 20910, USA) AD(Landessternwarte-Königstuhl, Heidelberg)
Abstract:
Most stars in our Galaxy appear to be stable and shine with essentially the same intensity over millions of years. Novae (and supernovae), on the other hand, suffer suddenly a gigantic explosion. Their brightness increases in only a day or two by more than several1 0,000 times, marking them often the brightest objects in the night sky, before they eventually fade in the course ofseveral years to theirformer relatively insignificant preoutburst brightness. These stars were called "novae" (which literally means "new stars"), long befare it was realized that they are not new at all, but existed already as stars long before their outburst. Nova Aquilae (1918) is actually one of the very few objects which had been known to exist before it turned into a "nova".
References:
Barnard, E. E.: 1919, Astrophysical Journal, 49, 199.
Clark, D. H. and Stephenson, F. R.: 1977, "The Historical Supernovae",
Pergamon Press, Oxford, New York.
Drechsel, H., Rahe, J., Holm, A. and Krautter, J.: 1980,Astronomyand
Astrophysics, submitted for publication.
Krafl, R. P.: 1964, Astrophysical Journal, 139,457.
Mustel, E. R. and Boyarchuk, A. A.: 1970, Astrophysics and Space
Sciences, 6, 183.
Payne-Gaposchkin, C.: 1957, "The Galactic Novae", Norlh-Holland
Pub!. Company, Amsterdam.
Rahe, J., Boggess, A., Drechsel, H., Holm, A. V., and Krautter, J.:
1980, Astronomy and Astrophysics. Letters, 88, L9.
Williams, R. E.: 1980, private communicalion.
13-14 (PDF)
M. P. Veron, P. Veron
The Density of the Broad-Line Emission Region in SEYFERT-1 Galaxies

ADS BibCode:
1980Msngr..22...13V
Author(s)/Affiliation(s):
Veron, M. P.; Veron, P.
AA(ESO) AB(ESO)
Abstract:
One of the characteristics of Seyfert 1 nuclei and quasars is the presence in their spectrum of broad permitted Iines or broad wings to the permitted lines. The forbidden lines show no such wings. Because broad He I and He Illines appear in the spectra of quasars and Seyfert 1 galaxies, it seems very likely that ions such as 0+, 0++ or Ne" actually do exist in the broad-line region and that the forbidden lines are suppressed by collisional de-excitation in a region with electron densities Ne > 107 -10+8 cm-3 (Souffrin, 1969, Astronomy and Astrophysics, 1, 305; Anderson 1970, Astrophysical Journal, 162, 743). Some class 1 Seyfert 1 galaxies and low redshift quasars exhibit an anomalously strong Hel A 5876 Aline; this has been believed to show an unusually large helium-to-hydrogen abundance ratio; however, in a high-density nebula, the He I triplet line intensities are significantly enhanced by electron collisional excitation. Theoretical and observational evidence shows that the gas which gives rise to the broad He Ilines is characterized by Ne- 5 x 109 cm -3 and T - 15,000°Kwith normal abundance (Netzer 1978, Ap. J, 219,822; Feldman and MacAlpine 1978, Ap. J, 221, 486).
13-13 (PDF)
ESO
List of Preprints Published at ESO Scientific Group

ADS BibCode:
1980Msngr..22R..13.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
118. M. Azzopardi, J. Breysaeher and G. Muralorio: Speetroseopy 01 the Small Magellanie Cloud Emission Line Star Hen S 18. Astronomy and Astrophysics, Research Note. Oelober 1980.
13-13 (PDF)
ESO
ESO Council Decisions

ADS BibCode:
1980Msngr..22Q..13.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
At its last meeting on November 26, 1980, the ESO Council took a number of decisions; among them we note:
13-13 (PDF)
ESO
Announcement - ESO Conference - Scientific Importance of High Angular Resolution at Infrared and Optical Wavelengths

ADS BibCode:
1980Msngr..22S..13.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
Announcement of an ESO Conference in Garching 24-27 March 1981
14-16 (PDF)
H. Schleicher, H. W. Yorke
Optical and Ultraviolet Spectroscopy of the Nuclei of Seyfert Galaxies

ADS BibCode:
1980Msngr..22...14S
Author(s)/Affiliation(s):
Schleicher, H.; Yorke, H. W.
AA(Universitäts-Sternwarte, Göttingen) AB(Universitäts-Sternwarte, Göttingen)
Abstract:
The launching of the International Ultraviolet Explorer (IUE) in 1978 has made the ultraviolet sky in the wavelength region from 1150 A to 3200 Aaccessible to detailed spectroscopic study. The IUE is a satellite in a geosynchronous orbit, equipped with a 45 cm telescope with two spectrographs. For a more detailed description of this satellite, the interested reader is referred to the article by A. Heck et al. (Messenger No. 15, Oec. 1978). Although the diameter of the IUE telescope is quite small-its size is more typical of an amateur telescope than of a scientific instrument-it has been used successfully even for extragalaclic spectroscopy.
16-17 (PDF)
H. Pedersen
Fast Photometry - New Facilities at La-Silla

ADS BibCode:
1980Msngr..22...16P
Author(s)/Affiliation(s):
Pedersen, H.
AA(ESO)
Abstract:
The standard photometric equipment at La Silla has 1 second of time as the shortest integration time. This is fully sufficient for most observing programmes. There are, however, several kinds of phenomena which have timescales of about a second or shorter. Among the fastest phenomena, one could mention the optical outbursts of the X-ray bursters (see The Messenger No. 18,34) or occultations of stars by objects in the solar system.
17-18 (PDF)
A. B. Muller
Pointing of the 3.6-METER Telescope

ADS BibCode:
1980Msngr..22...17M
Author(s)/Affiliation(s):
Muller, A. B.
AA(ESO)
Abstract:
The pointing of a telescope on a certain celestial object is achieved when the object is acquired in the field of view of the telescope and on the centre of a cross-wire system or any marking that indicates the centre of this field. Star acquisition with the 3.6 m telescope is computer-controlled. However, the behaviour of the telescope, mainly concerning f1exures in the telescope structure, misalignments in the telescope axes and optics, must be known in detail. To find the different contributions to the total pointing error, a pointing programme was developed at the Anglo-Australian Observatory by P. Wallace for the pointing of the Anglo-Australian telescope, and this programme was made available to the author, thanks to Donald Morton, Director of the AAO, and P. Wallace.
18-19 (PDF)
A. B. Muller
The ESO 1-METER Telescope Equipped with a Racine Wedge

ADS BibCode:
1980Msngr..22...18M
Author(s)/Affiliation(s):
Muller, A. B.
AA(ESO)
Abstract:
Since November 1980 a Racine wedge can be used in photometric programmes with the ESO Schmidt telescope.
19-20 (PDF)
ESO
Algunos Resumenes

ADS BibCode:
1980Msngr..22...19.
Author(s)/Affiliation(s):
ESO
AA(ESO)
Abstract:
EI "Palomar Observatory Sky Survey" es un medio auxiliar bien conocido y ütil para los astronomos. Todo el cielo dei hemisferio Norte esta captado en lotografias, cuyas reproducciones se encuentran archivadas en las bibliotecas de casi todos los observatorios importantes dei mundo.