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The Luminosity of the Classical Cepheid T VUL
Evans, Nancy R.
The classical Cepheid T Vul has been discovered to have a hot companion on International Ultraviolet Explorer satellite spectra. The companion has a spectral type of A0.8 V. The absolute magnitude of the Cepheid determined from the companion is Mv = -3.43 mag. Because the companion is significantly fainter and less massive than the Ceph…
Detection of a White Dwarf in a Visual Binary System
Boehm-Vitense, Erika
The F6 giant HD 160365 was detected to have a white dwarf companion about 8 arcsec south of the star. The UV energy distribution observed with IUE shows that the white dwarf has an effective temperature of 23,000 +/- 2000 K. If log g = 8 the Lya profile indicates an effective temperature around 24,500 K. Using the theoretical models by Wesemael et…
Ultraviolet Emission in the Dark Cloud Toward HD 62524
O'Donnell, James E.; Cardelli, Jason A.; Churchwell, Ed
We have obtained low resolution IUE short wavelength spectra at several positions within a ridge of molecular gas within the Gunn Nebula. Optical absorption line measurements toward HD 62542 indicate moderately high densities within the ridge. The physical appearance of the ridge, along with H-alpha and IRAS images of the nebula, suggest that wind…
PG 0027+260: an Example of a Class of Cataclysmic Binaries With Mysterious, But Consistent, Behavior
Thorstensen, John R.; Schmidt, Gary D.; Ringwald, F. A. +2 more
This paper reports extensive optical observations on the PG0027 + 260 binary, carried out on August 1984 with the 1.3 McGraw-Hill telescope and Mark II spectrometer at Michigan-Dartmouth-MIT Observatory on Kitt Peak. It is shown that this object is an eclipsing novalike variable with an orbital period of 3.51 hr. The PG0027 + 260 displays several …
On the Nature of the Symbiotic Binary CI Cygni
Stencel, R. E.; Kenyon, S. J.; Garcia, M. R. +4 more
An analysis of ultraviolet and optical spectroscopy is presented for the symbiotic binary CI Cyg. This system contains an M5 II asymptotic branch giant Mg of about 1.5 solar mass, transfering material at a few times 0.00001 solar mass/yr into a large accretion disk surrounding a main-sequence star with Mh of about 0.5 solar mass. A boundary layer …
Absolute Extinction and the Influence of Environment: Dark Cloud Sight Lines Toward VCT 10, 30, and Walker 67
Clayton, Geoffrey C.; Cardelli, Jason A.
The range of validity of the average absolute extinction law (AAEL) proposed by Cardelli et al. (1988 and 1989) is investigated, combining published visible and NIR data with IUE UV observations for three lines of sight through dense dark cloud environments with high values of total-to-selective extinction. The characteristics of the data sets and…
Hubble Space Telescope Imaging of Eta Carinae
Lauer, Tod R.; Currie, Douglas G.; Groth, Edward J. +5 more
New high spatial resolution observations of the material around Eta Carinae, obtained with the Hubble Space Telescope Wide Field/Planetary Camera, are presented. The star Eta Carinae is one of the most massive and luminous stars in the Galaxy, and has been episodically expelling significant quantities of gas over the last few centuries. The morpho…
Chromospherically active stars. IX. HD 33798 = V390 Aurigae: a lithium-rich rapidly rotating single giant.
Fekel, Francis C.; Marschall, Laurence A.
Results are presented of spectroscopic observations of HD 33798 obtained to determine if this star is a short-period binary and to examine its evolutionary status. Analysis of 40 radial velocities indicates no periodic velocity variations, suggesting that the star is single, so its rapid rotation is highly unusual. This rotation is inconsistent wi…
The current ability of HST to reveal morphological structure in medium-redshift galaxies.
Bershady, Matthew A.; Seitzer, Patrick; Keel, William C. +6 more
The capabilities of the Faint Object Camera (FOC) and the Wide Field Camera (WFC) are assessed on the basis of a brief program of single-orbit images of medium-faint galaxies. The FOC yielded a good resolved image of a compact galaxy at a blue magnitude J of 20.5 in a single-orbit exposure. WFC images have a survey capability that can include many…
H-Beta Photometry of V1010 Ophiuchi
Corcoran, M. F.; Guinan, E. F.; Siah, M. J.
An analysis is presented of previously unpublished intermediate and narrow band H-beta light curves of the short period eclipsing binary V1010 Oph. The temperature of the primary is determined directly by comparing the UV continuum with Kurucz model atmospheres and solve the broadband lightcurve using the Wilson-Devinney program. The present solut…