1999/06/28 by Gabriel W. Pratt, G. W. Pratt, B. J. M. Hassall +4 · 20 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Astrophysics and Star Formation Studies #Dwarf nova #Eclipse #Flux (metallurgy) #Light curve #ROSAT #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.1999.02900.x
published in Monthly Notices of the Royal Astronomical Society 309(4), 847-861 (Oxford University Press) · 16 pages, 14 figures, accepted for publication in MNRAS
arxiv created 1999/06/28 · openalex publication_date 1999/11/11 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present ROSAT X-ray and optical light curves of the 1994 February superoutburst of the eclipsing SU UMa dwarf nova OY Carinae. There is no eclipse of the flux in the ROSAT HRI light curve. Contemporaneous ‘wide B’-band optical light curves show extensive superhump activity and dips at superhump maximum. Eclipse mapping of these optical light curves reveals a disc with a considerable physical flare, even three days into the superoutburst decline. We include a later (1994 July) ROSAT PSPC observation of OY Car that allows us to put constraints on the quiescent X-ray spectrum. We find that while there is little to choose between OY Car and its fellow high-inclination systems with regard to the temperature of the emitting gas and the emission measure, we have difficulties reconciling the column density found from our X-ray observation with the column found in Hubble Space Telescope UV observations by Horne et al. The obvious option is to invoke time variability.