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HS0907+1902: a new 4.2hr eclipsing dwarf nova

B. T. Gaensicke·R. E. Fried·H. -J. Hagen·K. Beuermann·D. Engels·F. V. Hessman·D. Nogami·K. Reinsch
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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.

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B. T. Gaensicke, R. E. Fried, H. -J. Hagen, K. Beuermann, D. Engels, F. V. Hessman, D. Nogami, K. Reinsch. 2000-03-22. HS0907+1902: a new 4.2hr eclipsing dwarf nova. https://arxiv.org/abs/astro-ph/0003325

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