Astronomy and Astrophysics – Astronomy
Scientific paper
Apr 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995mnras.273..772w&link_type=abstract
Monthly Notices of the Royal Astronomical Society, Volume 273, Issue 3, pp. 772-784.
Astronomy and Astrophysics
Astronomy
51
Accretion, Accretion Discs, Binaries: Eclipsing, Stars: Individual: Ht Cas, Novae, Cataclysmic Variables, X-Rays: Stars
Scientific paper
X-ray and optical observations of the dwarf nova HT Cas, some simultaneous, are presented. The X-ray light curve shows that the X-ray source is eclipsed and comes from the near vicinity of the white dwarf. It must therefore be a boundary layer. The X-ray flux (0.1-1.2 keV) is ~5x10^-13 erg s^-1. The spectrum is consistent with an absorbed thermal bremsstrahlung model with temperature kT~2.4 keV and hydrogen column density n_H~1.8x10^20 cm^-2. The low luminosity in the boundary layer, L~5x10^30 erg s^-1, may be caused by having a low mass-transfer rate on to the white dwarf, of ~1x10^-12 M_solar yr^-1, or perhaps the presence of a rapidly rotating white dwarf. The optical observations show that HT Cas has low states where the accretion rate in the disc is dramatically reduced from the usual quiescent level. The drop from a normal to a low state can occur in less than two weeks. The measured white dwarf fluxes in the low state show that the white dwarf has a temperature of ~13200K, cooler than the temperature determined from the normal state of 18700K. The cooling of the white dwarf must occur in less than two weeks. The ROSAT observations were obtained during a low state.
Hassall B. J. M.
Naylor Tim
Ramseyer Tod Forrest
Wood Janet H.
No associations
LandOfFree
The discovery of an X-ray eclipse during a low state of the dwarf nova HT Cassiopeiae does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The discovery of an X-ray eclipse during a low state of the dwarf nova HT Cassiopeiae, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The discovery of an X-ray eclipse during a low state of the dwarf nova HT Cassiopeiae will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1830353