Messenger No. 40 (June 1985)
Radial velocities of stars in globular clusters - A look into Omega CEN and 47 TUC
Mayor, M.; Meylan, G.
AA(Geneve, Observatoire, Sauverny, Switzerland), AB(Geneve, Observatoire, Sauverny, Switzerland)
Kinematical data are presented from photoelectric cross-correlation studies of the globular clusters 47 Tuc and Omega Cen. The data were gathered on 298 stars in Omega Cen and 192 stars in 47 Tuc, distributed over 9.3 and 30.5 core radii, respectively. Radial velocities, velocity fields and dispersions, and the masses and mass-luminosity ratios are discussed with an eye to evidence for collapsed core remnants within the clusters.
Tentative Time-table of Council Sessions and Committee Meetings in 1985
R136a and the central object in the giant H II region NGC 3603 resolved by holographic speckle interferometry
Weigelt, G.; Baier, G.; Ladebeck, R.
AA(Erlangen-Nuernberg, Universitaet, Erlangen, West Germany), AB(Erlangen-Nuernberg, Universitaet, Erlangen, West Germany), AC(Erlangen-Nuernberg, Universitaet, Erlangen, West Germany)
Baier, G., Ladebeck, R., Weigelt, G.: 1985, Speckle interferometry of
the central object in the giant H11 region NGC 3603, submitted to
Cassinelli, J.P., Mathis, J.C., Savage, B.o.: 1981, Science 212,1497.
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1980,As~on.As~ophys. 84, 50.
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Astron. Soc. 200, 1 p.
Melnick, J.: 1983, The Messenger 32, 11.
Moffat, A.F.J., Seggewiss, W.: 1983, Astron. Astrophys. 125, 83.
Schmidt-Kaler, Th., Feitzinger, J.V.: 1981, in: The Most Massive Stars,
Proc. ESO workshop, eds. S. O'Odorico, O. Baade and K. Kjär,
Garching, Europ. Southern Obs., p. 105.
Walborn, N.R.: 1973, Astrophys. J. 182, L21.
Walker, A.R., O'Oonoghue, O.E.: R136: Multiple or Monster? in press.
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of High Angular Resolution at IR and Optical Wavelengths", eds.
M.H. Ulrich and K. Kjär, Garching, March 1981, p. 95.
Weigelt, G.: 1984, in Proc. of the lAU Colloquium No. 79: "Very Large
Telescopes, their Instrumentation and Programs, April 9-12, ESO,
Garching, p. 337.
Weigelt, G., Baier, G.: 1985, R136a in the 30 Oor nebula resolved by
holographic speckle interferometry, submitted to Astron. Astrophys.
Worley, C.E.: 1984, Astrophys. J. 278, L109.
Access to IRAS Data in ESO Member Countries
Nova-like objects and dwarf novae during outburst - A comparative study
Wargau, W. F.
AA(University of South Africa, Pretoria, Republic of South Africa)
Spectroscopic scans were made of two cataclysmic variables (CVs) containing dwarf stars in order to define a model for the observed burst phenomena. CVs have been classified into three groups according to their outburst periods: quick rises and falls, sustained peaks, and the presence of regular and superoutbursts. The present campaign covered the objects CPD-48 deg 1577 and HL CMa. Orbital period, spectral features, continuum distributions, and IR data are discussed. The two CVs had similar line features, line profile structures, and continuum shapes; however, no quiescent stage was observed for CPD-48 deg 1577, which also exhibited evidence for a magnetic field, an uncommon dwarf feature.
Two multi-object spectroscopic options at the ESO 3.6 m telescope.
In March, two instruments to obtain the spectra of several objects in a field in a single exposure were successfully tested at La Silla.
Submillimetre spectroscopy on La Silla.
Krügel, E.; Schulz, A.
AA(Max-Planck-Institut für Radioastronomie, Bonn) AB(Max-Planck-Institut für Radioastronomie, Bonn)
Who would play a Stradivari violin at a country dance? Or who would mix very old Scotch with Coca-Cola? Not uso But we do things that look equally improper in the eyes of many astronomers. We employ fine optical telescopes to observe at submillimetre wavelengths, although for our purposes the surface accuracy of the mirror could be 1,000 times worse. One excuse which we (and the ESO Observing Programmes Committee) can ofter is that at present there are no submillimetre telescopes that we could use instead of the optical ones. We believe that one can get information about starforming regions through submillimetre observations that cannot be obtained by other means. This article is an attempt to convince you that this is the case.
Spectroscopy of horizontal branch stars in NGC 6752
AA(CNR, Istituto di Astrofisica Spaziale, Frascati, Italy)
IUE spectra were obtained for the HB stars in the globular cluster NGC 6752 in an attempt to characterize the helium abundance in Pop II objects. The He abundance in globular clusters, which are situated in the galactic halo, is thought to be similar to the abundance in the first three minutes of the Big Bang. A lower limit of 0.14 for the mass was calculated. The value is lower than predicted for primordial He, which may indicate that sedimentation is occurring in the 16,000 K region observed.
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4. Caputo, F. 1985, Reports on Progress in Physics, in press.
5. Buonanno, R., Caloi, V., Castellani, V., Corsi, C. E., Fusi Pecci,
F. and Gratton, R. 1985, in preparation.
6. Caloi, V., Castellani, V., Danziger, J., Gilmozzi, R., Cannon, R. D.,
Hili, P. W. and Boksenberg, A 1985, preprint.
7. Heber, U., Kudritzki, R. P., Caloi, V., Castellani, V., Danziger, J.,
Gilmozzi, R. and Cannon, R. D. 1985, in preparation.
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List of ESO Preprints (March - May 1985)
Visible and infrared study of L.P.V. with the 1 M telescope
Bouchet, P.; Le Bertre, Th.
AA(European Southern Observatory, La Silla, Chile), AB(European Southern Observatory, La Silla, Chile)
Long-period variables (LPVs) were studied photometrically with the 1 m telescope at La Silla. LPVs are characterized by luminosity variations lasting 100-2000 days, low temperature giant or supergiant central stars, and carbon or oxygen overabundance. Most are surrounded by gas and dust shells. Star and shell data, including the distance, shell expansion velocity, central star effective temperature, optical depth of the dust shell, condensation temperature, mass loss rate, and total luminosity are provided. The survey covered IRC-30021, GL 3068, IRC-30023, and OH 353.60 - 0.23. Recent data for R For and IRC-30023 are discussed in detail.
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Neugebauer, G. and Leighton, R. B.: 1969, NASA SP-3047.
Salpeter, E. E.: 1974, Astrophys. J. 193,579.
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