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Optical and UV Spectroscopy of the Black Hole Binary Candidate LMC X-1
Thompson, I. B.; Bianchi, L.; Hutchings, J. B. +2 more
Both further optical spectroscopy of the binary star identified with LMC X-1, obtained between 1983 and 1985, and a series of IUE UV spectra taken during a 5 day interval in 1984 are presented. The optical data are used to refine the orbital period to 4.2288 days, and improved orbital parameters are derived. The velocity of the optical emission li…
Morphology and Nuclear Spectroscopy of Markarian 231
Hutchings, J. B.; Neff, S. G.
Deep optical imaging of Mkn 231 reveals twin (tidal?) tails, a linear nuclear feature at green wavelengths, and a very blue region 4 arcsec south of the nucleus. Much of the central part of the galaxy is red, but there are complex areas of blue luminosity outside this, and a sharp edge to the luminosity at a distance of about 16 arcsec from the ce…
Chromospheric and Transition-Region Emission from Young Solar-Type Stars in Clusters, Kinematic Groups, and the Field
Soderblom, David R.; Clements, Sandra D.
We have examined the strength of chromospheric and transition-region emission in solar-type stars that have been suggested to be members of the Ursa Major Group and Hyades Group (originally selected on kinematic grounds), as well as stars in the Hyades Cluster and other young stars of the solar neighborhood. We find that indices of the Ca II (R'
The SN Stars: Magnetically Controlled Stellar Winds Among the Helium-Weak Stars
Shore, Steven N.; Brown, Douglas N.; Sonneborn, George
The authors report observations of magnetically controlled stellar mass outflows in three helium-weak sn stars: HD 21699 = HR 1063, HD 5737 = α Scl, and HD 79158 = 36 Lyn. IUE observations show that the C IV resonance doublet is variable on the rotational timescale but that there are no other strong-spectrum variations in the UV. Magnetic fields, …
Anomalous Dust in the Open Cluster Trumpler 37
Fitzpatrick, Edward L.; Clayton, Geoffrey C.
New IUE data were obtained towards stars in the open cluster Trumpler 37. Extinction curves derived from these data show that the anomalous dust detected towards HD 204827 and HD 210072 is not unique to those lines of sight but occurs generally in that region of the sky. The dust is apparently associated with the Trumpler 37 cluster, which forms t…
The Initial Mass Function for Early-Type Stars in Starburst Galaxies
Sekiguchi, Kazuhiro; Anderson, Kurt S.
The IMF slope of early-type stars in starburst galaxies is investigated using IUE observations and a technique that utilizes mass-linewidth relations for early-type stars. Fourteen low-resolution IUE spectra of eight starburst galaxies and three H II region galaxies are used to obtain line-strength ratios Si IV (λ1400)/C IV (λ1550). These are comp…
Chromospherically Active Stars. III. HD 26337 = EI Eri: an RS CVn Candidate for the Doppler-Imaging Technique
Fekel, Francis C.; Gillies, Kim; Quigley, Robert +1 more
The variable star HD 26337 = EI Eri is a chromospherically active G5 IV single-lined spectroscopic binary with a period of 1.94722 days. It has moderate strength Ca II H and K emission and strong ultraviolet emission features, while Hα is a weak absorption feature that is variable in strength. The inclination of the system is 46°±12°, and the unse…
Time-Resolved IUE Studies of Cataclysmic Variables. I. Eclipsing Systems of IP Peg, PG 1030 + 590, and V1315 AQL
Szkody, Paula
IUE time-resolved spectra of the high-inclination cataclysmic variables IP Peg, PG 1030+590, and V1315 Aql are analyzed in order to determine the characteristics of the disks, hotspots, and white dwarfs. The UV continuum flux distributions are generally flatter than systems of low inclination and high mass-transfer rate, and the white dwarfs/inner…
Mass to Line Strength Relations from IUE Spectra of Early-Type Stars
Sekiguchi, Kazuhiro; Anderson, Kurt S.
An extensive survey of the 1200 - 1900 Å region in OB type stellar spectra obtained from the IUE archives has been used to establish line-strength versus spectral-type relationships. One hundred and sixty-three low-resolution IUE spectra of 124 well-classified O3 to B5 stars were examined. The authors confirm earlier results that the equivalent wi…
Ultraviolet and Optical Observations of AG Draconis
Lutz, J. H.; Lutz, T. E.; Dull, J. D. +1 more
IUE satellite observations and ground-based spectroscopic observations of the yellow symbiotic star AG Dra obtained at irregular intervals from 1975 to 1984 are presented. No forbidden lnes are observed in the optical, indicating a high density. The hydrogen emission lines often show a second blueshifted component that is not as strong as the main…