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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…
A Study of the Young Massive Cluster N90 in the SMC
Thompson, I. B.; Hutchings, J. B.; Cartledge, S. +1 more
We present optical and UV spectra of O and B stars in the compact nebulous cluster Henize N90 in the SMC. The brightest stars are of type O and B, although our optical and UV classifications do not all agree closely. We discuss the spectra, effective temperatures, bolometric luminosities, extinction, stellar winds, and the evolutionary state of th…
UV Observations of the Cool DBQA5 White Dwarf LDS 678A: Limits on the Atmospheric Composition, Pressure Shift, and Gravitational Redshift Derived from C I 2479
Sion, Edward M.; Koester, Detlev; Liebert, James W. +5 more
A high-resolution ultraviolet spectrum of the helium-rich degenerate LDS 678A, obtained with the International Ultraviolet Explorer (IUE) satellite, is presented. LDS 678A is the coolest metallic line degenerate (DQ or DZ) yet observed with the IUE echelle. These observations provide a detailed line profile of the strong C I 2479 absorption line a…
On the Utility of Low Resolution IUE Spectroscopy of the 2800 A MG II Lines as a Stellar Chromosphere Indicator
Smith, Graeme H.; O'Connell, Robert W.; Burstein, David +2 more
Low resolution IUE spectroscopy of the 2800-A Mg II h and k lines is shown to provide a useful means for documenting chromospheric activity among relatively young dwarf stars. An index I(Mg II) has been defined which measures the integrated flux in the region 2784-2814 A relative to the flux interpolated from nearby comparison regions. Values of t…