Exosat and IUE observations of SW UMa during superoutburst

Journal Article · Sun May 01 04:00:00 EDT 1988 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/166286· OSTI ID:6990906

Szkody, P; Osborne, J; Hassall, B J.M.

IUE and Exosat observations obtained during the March 1986 superoutburst of the SU UMa type dwarf nova SW UMa are presented. The observations show the presence of a hot, extensive, optically thick disk. The UV fluxes show an increase of 1000 over the quiescent values, implying a large increase in mass accretion rate. The Exosat obserations show an increase in the soft X-ray count rate by a factor of 44 over quiescence, while the medium-energy flux remains undetected. The most surprising result is that the softness ratio in superoutburst is similar to the quiescent value of 0.3. No variation at the orbital or spin periods or at the superhump period are evident in the superoutburst X-ray data. A transient variation is observed at 5.1 minutes similar to that observed in the optical a few days after the X-ray observations. 35 references.

• Research Organization: Washington Univ., Seattle (USA); EXOSAT Observatory, Noordwijk (Netherlands); Oxford Univ. (England)
• OSTI ID: 6990906
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 328; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOUNDARY LAYERS
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
DWARF STARS
ELECTROMAGNETIC RADIATION
ERUPTIVE VARIABLE STARS
IONIZING RADIATIONS
LAYERS
NOVAE
RADIATIONS
SOFT X RADIATION
SPECTRA
STAR ACCRETION
STAR EVOLUTION
STARS
ULTRAVIOLET SPECTRA
VARIABLE STARS
VARIATIONS
WHITE DWARF STARS
X RADIATION