Search Publications
Physical studies of asteroids. XXVIII. Lightcurves and photoelectric photometry of asteroids 2, 14, 51, 105, 181, 238, 258, 369, 377, 416, 487, 626, 679, 1048 and 2183
Erikson, A.; Albrecht, R.; Schober, H. J. +5 more
Photoelectric photometry of 15 mainbelt asteroids was carried out at ESO, La Silla, Chile with the 0.50 m ESO, the 0.60 m Bochum, the 0.90 m Dutch and 1.0 m ESO telescopes, at CTIO, Chile with the 0.60 m Lowell and 1.0 m telescopes, and at OHP, France with 1.0 m telescope at Mt. Chiran. We have derived new rotation periods and present composite li…
Detection of episodic mass outflow in the newly discovered hot DO white dwarf RE 0503-289.
Barstow, M. A.; Sion, E. M.
We report the unexpected detection of variable mass outflow from the very hot (Teff =70000 K), He-rich DOZ1 degenerate RE 0503-289. This detection is based upon our analysis of absorption-line core strength variations and blueward asymmetries in two lUE echelle high-dispersion images obtained 13 months apart. The oufflow has a terminal velocity of…
The HST Quasar Absorption Line Key Project. IX. an Emission-Line Study of PG 2251+113
Turnshek, David A.; Schneider, Donald P.; Savage, Blair D. +9 more
We present HST and quasi-simultaneous ground-based observations of the z = 0.3252 QSO PG 2251 + 113. We find a correlation between line widths and the critical density for de-excitation of the forbidden emission lines observed in this object. We can show that this correlation also applies to the semiforbidden and possibly also the permitted lines …
Planetary Camera Imaging of the Counter-Rotating Core Galaxy NGC 4365
Forbes, Duncan A.
We analyze F555 W(V) band Planetary Camera images of NGC 4365, for which ground-based spectroscopy has revealed a misaligned, counter-rotating core. Line profile analysis by Surma indicates that the counter-rotating component has a disk structure. After deconvolution and galaxy modeling, we find photometric evidence, at small radii to support this…
Infrared Observations of Comet Austin (1990 V) by the COBE/Diffuse Infrared Background Experiment
Reach, W. T.; Lisse, C. M.; Kelsall, T. +4 more
Comet Austin was observed by the Cosmic Background Explorer (COBE)/Diffuse Infrared Background Experiment (DIRBE) with broadband photometry at 1-240 micrometers during the comet's close passage by Earth in 1990 May. A 6 deg long (6 x 106 km) dust tail was found at 12 and 25 micrometers, with detailed structure due to variations in parti…
Hydrodynamic model of Kepler's supernova remnant constrained by EINSTEIN and EXOSAT X-ray spectra.
Ballet, J.; Rothenflug, R.; Magne, B. +1 more
We have used the EXOSAT spectrum of Kepler's supernova remnant (including the Fe K line and the high-energy continuum) to further constrain its models. On the basis of the large abundances of Si, S and Fe required by a Sedov model, we have focused on models of young supernova remnants in which the reverse shock (propagating into the stellar ejecta…
The AM CVn Systems: A Bibliographic Search for Clues to Their Cataclysmic Nature
Ulla, A.
The nature of AM CVn, GP Com, CR Boo, and V803 Cen is investigated in detail on the basis of a comprehensive review of all that to-date is known about these systems. They are classified as cataclysmic variables, within these forming the subclass of AM CVn systems; their distinguishing characteristic is an extreme H-deficiency. Besides, they are ve…
Highly Ionized Gas in the Galactic Disk: The L = 295 degrees , B = 0 degrees Interarm Direction
Sembach, Kenneth R.
I present new high-resolution measurements of ultraviolet interstellar absorption lines toward three distant stars in the Galactic disk in the general direction l = 295 deg, b = 0 deg. The high ionization lines of Si IV and C IV toward HD 100276, HD 103779, and HD 104705 show substantial variations on angular scales of less than 1 deg, or about 50…
Ultraviolet Observations of the Accretion Disk in LMC X-3
Hutchings, J. B.; Crampton, D.; Cowley, A. P. +1 more
We report information obtained from a series of IUE low-resolution spectra and two HST UV spectra of LMC X-3. The HST spectra are used to identify disk emission lines and interstellar absorptions as well as to fit continuum models, which indicate the presence of a hot disk component. The IUE observations, mainly taken over ~1.5 years, were intende…
Classification of the HIPPARCOS Input Catalogue Using the Kohonen Network
Hernandez-Pajares, M.; Floris, J.
The unsupervised classification with respect to stellar populations of 106 000 of the 118 000 Hipparcos input catalogue stars is presented, in terms of angular position and velocity, apparent magnitude and spectral type. The classification is performed first by merging the real data with a small sample of synthetic stars, which are representative …