Search Publications
Studies of Yellow Semiregular(SRd) Variables
Percy, John R.; Kolin, David L.
We have used the Hipparcos database of epoch photometry to study the variability of several yellow semiregular(SRd) variables. For some of the stars (V847 Cas, RW Cep, BM Sco, CE Vir), the results were inconclusive. For SX Lac and TY Vir, the periods found were consistent with the General Catalogue of Variable Stars (190 and 50 days respectively).…
Period Changes in Population II Cepheids: TX Del and W Vir
Percy, John R.; Hoss, Jonathan X.
We have used the Hipparcos database of epoch photometry to study the variability of two Population II Cepheids: TX Del and W Vir. We have constructed (O-c) diagrams for these stars, using the new data and data from the literature. The period of TX Del is decreasing, at a rate which is consistent with evolutionary predictions. THe periodchange of W…
The Rotation Rate and the Surface Temperature of the Hot, Accreting White Dwarf in the Dwarf Nova RX Andromadae
Szkody, P.; Cheng, F. H.; La Dous, C. +3 more
We obtained Hubble GHRS phase-resolved spectroscopic observations of the dwarf nova RX Andromadae at three times in its outburst cycle: (1) near the end of an extraordinarily deep and long dwarf nova quiescence, 3 months after the last previous outburst; (2) during the rise to outburst; and (3) near the end of a decline from outburst. The spectral…