Rotational and Cyclical Variability in γ Cas

نویسندگان

  • Myron A. Smith
  • Ethan Vishniac
چکیده

γ Cas is an unusual classical Be star for which the optical-band and hard X-ray fluxes vary on a variety of timescales. We report results of a nine-year monitoring effort on this star with a robotic ground-based (APT) telescope in the B, V filter system as well as simultaneous observations in 2004 November with this instrument and the Rossi X-ray Timing Explorer (RXTE) telescope. Our observations disclosed no correlated optical response to the rapid X-ray flares in this star, nor did the star show any sustained flux changes any time during two monitored nights in either wavelength regime. Optical light curves obtained in the APT program revealed, consistent with an earlier study by Robinson et al., that γ Cas undergoes ∼3%-amplitude cycles with lengths of 60–90 days. Our observations in 2004 showed a similar optical cycle. Over the nine days

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تاریخ انتشار 2006