HT-Cassiopeia is a U Geminorum-type variable star (a.k.a. dwarf nova), a close binary cataclysmic variable star system consisting of a white dwarf that accretes matter from its companion star. In addition, HT-Cas is an eclipsing binary with a very short orbital period (~106 min). Because of this, HT-CAs lends itself well to close examination of it's components via photometric and spectroscopic evaluation. (e.g. Eclipse mapping the flickering sources in the dwarf nova HT Cassiopeia1)).


Observation JD 2455504


This is a time series observation of HT Cas. Observation conditions were good and lasted from just after midnight until just before dawn. The accompanying image shows the star field with HT Cas labeled as “V” and the comparison stars marked as C1 and C2. HT Cas is at this time in Nova outburst with some very interesting super hump variations. Normally a 19th Magnitude star, HT Cas is currently varying between Mag. 13.37 and 12.17.

Notice that this light curve captures two complete orbital periods, demonstrating the period, and by examination of the super humps, the the inclination of the WD's accretion disk.


1) R. Baptista, B. Borges, V. Kolokotronis, O. Giannakis, C.J. Papadimitriou, May 2011,

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