Search Publications
Binary Star Orbits From Speckle Interferometry. V. A Combined Speckle/Spectroscopic Study of the O Star Binary 15 Monocertis
Gies, Douglas R.; Shara, Michael M.; Penny, Laura R. +7 more
We report on the discovery of a speckle binary companion to the O7 V (f) star 15 Monocerotis. A study of published radial velocities in conjunction with new measurements from Kitt Peak National Observatory (KPNO) and IUE suggests that the star is also a spectroscopic binary with a period of 25 years and a large eccentricity. Thus, 15 Mon is the fi…
PG 0308+096 and PG 1026+002: Two New Short Period Binary Stars Resulting From Common-Envelope Evolution
Green, Richard F.; Sion, Edward M.; Saffer, Rex A. +5 more
Ultraviolet spectroscopy, optical spectroscopy, and spectrophotometry have been used to study the excess UV stars PG 0308 + 096 and PG 1026 + 002. Both objects are short-period binary systems, each containing a DA white dwarf star and a dM star. Orbital periods of approximately 0.284 day for PG 0308 + 096, and aproximately 0.597 day for PG 1026, h…
Hubble Space Telescope / Faint Object Camera Observations of the Inner Regions of the Galactic Globular Cluster M15
Paresce, F.; Ferraro, F. R.
A set of high resolution images of the core of the Galactic Globular Cluster M15 (NGC 7078) were obtained for the first time with the Faint Object Camera on the HST through the f/48-F140W, f/48-F220W and f/96-F342W ultraviolet filters. Two UV-Color-Magnitude Diagrams are presented for the approximately 300 objects measured in the 22 arcsec x 22 ar…
Masses and Densities of Pluto and Charion
Null, G. W.; Owen, W. M.; Synnott, S. P.
We have analyzed HST Wide Field Camera CCD images of Pluto, Charon, and a background star to observe Pluto's barycentric motion and to determine the individual masses and bulk densities of Pluto and Charon. The most fundamental new result was an accurate solution for a previously undetermined parameter, the Charon/Pluto mass ratio q; the new solut…
IUE Temperatures for White Dwarf Stars in and Around the ZZ Ceti Instability Strip
Kepler, S. O.; Nelan, E. P.
We have analyzed all the archival IUE images of the DA4 and DA5 white dwarfs with model atmosphere fluxes incorporating the quasi-molecular opacities to obtain a consistent set of temperatures for both the variables and nonvariables in and around the ZZ Ceti instability strip. We have found four nonvariable stars inside the instability strip. Take…
NGC 4313. II. Hubble Space Telescope I-Band Surface Photometry of the Nuclear Region
Benedict, G. F.; Franz, O. G.; Hemenway, P. D. +11 more
We present a Hubble Space Telescope I-band Planetary Camera image of the nuclear region of NGC 4314. This is an anemic barred galaxy with recent star formation confined to a nuclear ring. These data resolve the nuclear ring into multiple sites of new star formation and resolve associated dust lanes into discrete clouds. Unsharp masking of a Lucy-R…
Imaging of the Gravitational Lens System PG 1115+080 With the Hubble Space Telescope
Holtzman, J. A.; Ewald, S. P.; Schneider, D. P. +14 more
This paper is the first of a series presenting observations of gravitational lenses and lens candidates, taken with the Wide Field/Planetary Camera (WFPC) of the Hubble Space Telescope (HST). We have resolved the gravitational lens system PG 1115+080 into four point sources and a red, extended object that is presumably the lens galaxy; we present …
RE 1016-053: A Pre-Cataclysmic Binary, and the First Extreme Ultraviolet and X-Ray Detections of DAO White Dwarf
Barstow, M. A.; Bergeron, P.; Holberg, J. B. +4 more
Photometric observations and analysis of the optical, UV, EUV, and X-ray spectra are presented for the EUV/X-ray source RE 1016-53. Multiwavelength observations of RE 1016-53 point out that it is a precataclysmic binary. Optical spectra exhibit the steep blue continuum and Balmer absorption typical of a hot white dwarf, but there are bright, narro…
Chromospherically active Stars. XI. Giants With Compact Hot Companions and the Barium Star Scenario
Henry, Gregory W.; Fekel, Francis C.; Busby, Michael R. +1 more
We have determined spectroscopic orbits for three chromsopherically active giants that have hot compact companions. They are HD 160538 (KO III + wd, P = 904 days), HD 165141 (G8 III + wd, P approximately 5200 days), and HD 185510 (KO III + sdB, P = 20.6619 days). By fitting an IUE spectrum with theoretical models, we find the white dwarf companion…
The Violent Interstellar Environment Around the Wolf-Rayet Star HD 192163
Nichols-Bohlin, Joy; Fesen, Robert A.
IRAS Skyflux IR images, high-dispersion IUE UV spectra, optical spectra, and optical interference filter images are used to investigate the nature of the interstellar environment around the Wolf-Rayet star HD 192163. IRAS images show an apparent 1.5 x 1.8 deg IR emission shell very nearly centered on HD 192163, which is designated G75.5+2.4. It is…