[Previous] | [Session 54] | [Next]
P. M. Saz Parkinson, E. D. Bloom, D. Tournear, W. B. Focke (SLAC, Stanford University), P. S. Ray, M. T. Wolff, K. S. Wood (Naval Research Laboratory), J. D. Scargle (NASA/Ames Research Center)
We present an analysis of long term X-ray monitoring observations of Circinus X-1 (Cir X-1) made with four different instruments: Vela 5B, Ariel V ASM, Ginga ASM, and RXTE ASM, over the course of more than 30 years. We use Lomb-Scargle periodograms to search for the ~16.5 day orbital period of Cir X-1 in each of these data sets and from this derive a new orbital ephemeris based solely on X-ray measurements, which we compare to the previous ephemerides obtained from radio observations. We obtain dynamic periodograms (both Lomb-Scargle and PDM) of Cir X-1 during the RXTE era, showing the period evolution of Cir X-1, and also displaying some unexplained discrete jumps in the location of the peak power.
[Previous] | [Session 54] | [Next]
Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.