Optical, IUE, and ROSAT Observations of the Eclipsing Nova-like Variable V347 Puppis (LB 1800)
Abstract
Using time-resolved optical spectroscopy and UBVRI and high-speed photometry obtained at Mount Stromlo Observatory, Mount John University Observatory, and the South African Astronomical Observatory; International Ultraviolet Explorer (IUE) ultraviolet spectroscopy; and Roentgen Satellite (ROSAT) survey X-ray fluxes, we present a study of the accretion disk, hot spot, and emission line regions in the bright eclipsing nova-like variable V347 Pup (LB 1800). In the optical and UV, V347 Pup is a strong emission line source with a continuum spectrum which is remarkably red for a high-M cataclysmic variable. Consistent with its high inclination, we interpret the continuum spectrum as the superposition of the spectrum of the cool (Teff approximately 7000 K) outer edge and the hot (Teff approximately 100,000 K) inner regions of a self-eclipsed accretion disk. For the assumed parameters, the model matches the level and shape of the observed spectrum for an inclination of approximately 88 and a distance of approximately 300 pc. The prominent hump in the optical and UV light curves just before eclipse manifests the presence of the hot spot where the accretion stream strikes the edge of the disk. The wavelength dependence of the amplitude of the hump is best modeled by a spot having an effective temperature of approximately 25,000 K and an area of approximately 3 x 1018 sq cm if the spot radiates like a blackbody, or an effective temperatue of approximately 14,000 K and an area of approximately 3 x 1019 sq cm if it radiates with a stellar spectrum. In either case, the hot spot produces only one-tenth of the predicted luminosity for the assumed mass-transfer rate of 10-8 solar mass/yr. Either the hot spot is 'buried' in the edge of the accretion disk, or a significant fraction of its luminosity is radiated away in lines. The difference in azimuth between the peak of the hump and the dynamically expected location of the hot spot suggests that the spot's emitting surface is rotated forward by approximately 36 deg relative to the edge of the disk.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1994
- DOI:
- 10.1086/173894
- Bibcode:
- 1994ApJ...424..347M
- Keywords:
-
- Accretion Disks;
- Cataclysmic Variables;
- Eclipsing Binary Stars;
- Ultraviolet Spectra;
- X Ray Spectra;
- Astronomical Photometry;
- Astronomical Spectroscopy;
- Emission Spectra;
- Iue;
- Rosat Mission;
- Astrophysics;
- STARS: BINARIES: ECLIPSING;
- STARS: NOVAE;
- CATACLYSMIC VARIABLES;
- STARS: INDIVIDUAL CONSTELLATION NAME: V347 PUPPIS;
- ULTRAVIOLET: STARS