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On the Nature of the Symbiotic Star BF Cygni
Kenyon, S. J.; Mikolajewska, J.; Mikolajewski, M.
Optical and ultraviolet spectroscopy of the symbiotic binary BF Cyg obtained during 1979-1988 is discussed. This system consists of a low-mass M5 giant filling about 50 percent of its tidal volume and a hot, luminous compact object similar to the central star of a planetary nebula. The binary is embedded in an asymmetric nebula which includes a sm…
Eclipsing Binary Stars as Tests of Gravity Theories: The Apsidal Motion of AS Camelopardalis
Guinan, Edward F.; Boyd, Patricia T.; Maloney, Frank P.
AS Camelopardalis is an 8th-magnitude eclipsing binary that consists of two main-sequence (B8 V and a B9.5 V) components in an eccentric orbit (e = 0.17) with an orbital period of 3.43 days. Like the eccentric eclipsing system DI Herculis, and a few other systems, AS Cam is an important test case for studying relativistic apsidal motion. In these …
The High-Resolution Spectrum of the Pulsating, Pre-White Dwarf Star PG 1159-035 (GW Vir)
Husfeld, D.; Sion, E. M.; Wesemael, F. +3 more
High-resolution and low-resolution UV spectra and a high-resolution optical spectrum were obtained for PG 1159-035, revealing apparent photospheric absorption features with defined cores from N V 1240 A, N IV 1270 A, O V 1371 A, and C IV 1550 A. The photospheric velocity derived using all of these lines except for C IV is about +35 km/s. Equivalen…
The Binary Companion of the Classical Cepheid AW Per
Evans, Nancy Remage
An analysis of IUE spectra of the companion of AW Per shows it to be an extreme BpSi/HeW star with a spectral type of B7 V to B8 V. The flux of the composite spectrum from 1200 A through V is found to be well matched by F7 Ib and B8 V standard stars with Delta M(V) = 3.1 mag. The results suggest that the mass of the Cepheid must be greater than 4.…
Chromospherically Active Stars. VI. HD 136901 = UV CrB: A Massive Ellipsoidal K Giant Single-Lined Spectroscopic Binary
Kirkpatrick, J. Davy; Fekel, Francis C.; Strassmeier, Klaus G. +1 more
The variable star HD 136901 = UV CrB is a chromospherically active K2 III single-lined spectroscopic binary with an orbital period of 18.665 days. It has modest-strength Ca H and K emission and UV features, while H-alpha is a strong absorption feature containing little or no emission. The inclination of the system is 53 + or - 12 deg. The v sin i …
The VV Cephei Star V641 Cassiopeiae
Guinan, Edward F.; Shaw, J. Scott
Ultraviolet spectra of the variable star V641 Cas taken with the IUE satellite have confirmed the VV Cephei nature of this object. The observations are consistent with the variable being a M3 I + B2 V-III system with E(B-V) = 0.55 mag lying in the Perseus arm of the Galaxy. In spite of V641 Cas having the largest light variation in the visible of …
IUE Spectra of HD 269665 (Sk -68 110), a Hot Subdwarf in the Direction of the Large Magellanic Cloud
Hill, Robert S.; Smith, Andrew M.
Comparison of high- and low-resolution IUE spectra of HD 269665 (Sanduleak -68 deg 110) show that the star is a subdwarf with a temperature in the range 30,000-50,000 K. The visual spectrum shows Balmer lines and weak He II 4686 A lines. Balmer-line width and a fit of the UV-visual flux distribution using the Blackwell-Shallis (1977) algorithm yie…
Effects of SN 1987A on the Interstellar Medium around it
Bohm-Vitense, Erika; Boggs, Don; Morgan, Siobahn
It is shown that the interstellar spectrum from SN 1987A in the LMC shows a rather strong component in C IV and Si IV, and possibly a weak component in N V, at a velocity of about 300 + or - 10 Km/s. In the spectra of the neighboring stars HD38268 and R123, a component at this velocity is only seen in low-ionization lines, not in the C IV, or N V …