HS0907+1902: a new 4.2hr eclipsing dwarf nova

Authors :: Gaensicke, B. T.
Fried, R. E.
Hagen, H. -J.
Beuermann, K.
Engels, D.
Hessman, F. V.
Nogami, D.
Reinsch, K.
Publication Year :: 2000
Publisher :: arXiv, 2000.
Abstract: We report on follow-up spectroscopy and photometry of the cataclysmic variable candidate HS0907+1902 selected from the Hamburg Quasar Survey. B, V, and R photometry obtained during the first observed outburst of HS0907+1902 (V~13) reveals deep eclipses (DeltaV~2.1-2.8) and an orbital period Porb=4.2h with the eclipse depth decreasing to the red. The outburst eclipse profiles are symmetric, indicating an axisymmetrical brightness distribution in the accretion disc. We derive an inclination i~73deg-79deg from the eclipse duration. The quiescent spectrum obtained with the Hobby-Eberly Telescope shows double peaked emission lines of HI, HeI and FeI,II and clearly identifies the system as a dwarf nova. Absorption features of the secondary star are detected at red wavelengths from which a spectral class M3+-1.5 and a distance of d=320+-100pc are derived.<br />Comment: 4 pages A&A-PSLatex, 5 Figures, accepted for publication in A&A Letters