Search Publications
The Nature of TT Hydrae
Etzel, Paul B.
Photometric solutions are made of previously published photoelectric light curves of TT Hydrae. The WINK model is employed to give radii of rA = 0.0894 and rB = 0.2431, and an orbital inclination of i = 84.4 deg. Spectrophotometry is presented and analyzed to give revised spectral types of B9.5 V and phase-variable G9 to K1 I…
The Companion of the White Dwarf G29-38 as a Brown Dwarf
Greenstein, Jesse L.
The strong infrared excess discovered by Zuckerman and Becklin (1987) in the white dwarf G29-38 (ZZ Psc) has been ascribed to a "brown dwarf". A variety of Palomar spectra of the white dwarf shows it to be an essentially normal DA4V, without spectral peculiarities that might have arisen from accretion or interaction with a close companion. The mul…
The Algol-like Binary TT Hydrae: The Stars, Circumstellar Matter, and Superionized Plasma
Plavec, Mirek J.
The characteristics of the eclipsing binary system TT Hydrae are now determined with a reliability surpassing many other Algol-like binaries. The primary component is a B9.5 V main-sequence star with a mass of 2.25 m_sun;, radius 1.9 R_sun;, effective temperature 9800K, and surface gravity log g = 4.23. The secondary star has a mass of 0.41 m_sun;…
A Spectrophotometric Study of IR GEM at Outburst and Quiescence
Garnavich, Peter; Szkody, Paula; Feinswog, Laurie
The authors present optical spectra with 2.5 Å resolution obtained throughout the orbit of the SU UMa cataclysmic variable IR Gem during a five day sequence beginning at an outburst state and ending at quiescence. In addition, B magnitude light curves and IUE spectra throughout other quiescent-state orbits are discussed. The broad absorption and n…
The Ultraviolet Spectra of M31 Globular Clusters
Cowley, A. P.; Burstein, D.
Ultraviolet spectra of 11 of the brightest globular clusters in M31 show that some exhibit residual flux below 3000 A, greater than that expected from the bright, evolved stars in the cluster. There seems to be no apparent correlation of the strength of this ultraviolet flux with parameters such as metallicity, U-B color, visual magnitude, x-ray e…
Ultraviolet and Optical Spectra of Broadline Radio Galaxies
Peterson, Bradley M.; Wagner, R. Mark; Crenshaw, D. Michael
Near-simultaneous ultraviolet and optical spectra of three broadline radio galaxies (3C 382, 3C 445, and PKS 2349 - 014) have been obtained, and the emission lines of Lyα, Hβ, and Hα have been deconvolved into narrow and broad components; published fluxes for 3C 390.3 are also included in this study. Although the broad Lyα/Hβ ratios in these objec…
The Spatial Distribution of Ultraviolet Line and Continuum Emission in Herbig-Haro Objects
Lee, M. G.; Raga, A. C.; Brugel, E. W. +4 more
Using archival IUE data and "monochromatic" CCD images in the optical range, the authors compare the spatial distribution of ultraviolet and optical emission in Herbig-Haro objects. Specifically, they consider the objects HH 1, HH 2, HH 24, HH 32, HH 43, and HH 47. Spatial distributions have been studied in the UV lines C IV 1550, C III] 1909, C I…
An Optical and UV Investigation of the IRAS Seyfert Galaxy 1319-164
Hutchings, J. B.; De Robertis, M. M.; Pitts, Ronald E.
We present optical and UV spectroscopy, and optical-imaging observations of the bright IR-selected Seyfert galaxy 1319 - 164. We find that the nucleus is reddened by E_B-V_ = 0.3 mag, both in the lines and continuum. The galaxy is large and contains little, if any, spiral structure. There are low-brightness structures at about 5" from the nucleus,…
Chromospherically Active Stars. IV. HD 178450=V478 LYR: an Early-Type BY Draconis Type Binary
Fekel, Francis C.
The variable star HD 178450 = V478 Lyr is a chromospherically active G8 V single-lined spectroscopic binary with a period of 2.130514 days. This star has strong ultraviolet emission features and a filled-in Hα absorption line which is variable in strength. It is classified as an early-type BY Draconis system and is similar in many respects to the …
Hot White Dwarfs, OB Subdwarfs, and Dark Clouds
Bessell, M. S.; Wickramasinghe, D. T.; Wegner, Gary +1 more
The authors describe a method of using UBV photographic photometry to survey obscured regions in the Galactic plane for hot white dwarfs and OB subdwarfs. From an initial survey of two regions, the first towards the Coalsack, and the second covering part of the Scorpius-Centaurus cloud, the authors have found at least six white dwarfs, one probabl…