HD 64535

Selection of standard stars for photometric observations with the 91-cm reflector at Okayama Not Available
The infrared light curve of U Geminorum IR observations of the dwarf nova U Geminorum show the periodic doublewave of an ellipsoidal variable, with an amplitude of 0.25 mag, which isreproduced in calculations of the rotational light curve of the tidallydistorted red dwarf star in the system. This star, which is required tofill U Geminorum's Roche lobe, exhibits a variation amplitude which isconsistent with (1) the expected geometrical elements of the system, (2)convective gravity darkening, and (3) a moderate degree of limbdarkening. Agreement with observations is improved by the reflectioneffect if only about 1/4 of the observed hot star luminosity is seen bythe cool star. The ellipsoidal variation marks the orbital conjunctionsfor reference with the times of the optical eclipse of the bright spot.The system's IR colors are those of a middle M dwarf star.
Three-Color Photometry of U Geminorum During an Outburst Not Available

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