We present a study of the long-term variability of Cyg X-1 using data from
the RXTE/ASM and the RXTE/PCA during the time between the two soft states of
1996 and 2001/2002. This period has been characterized by many short ASM
flaring episodes which we have identified as "failed state transitions". The
150 d period which has been seen before and shortly after the 1996 soft state
is not obviously present in the ASM rate during most of this time. Applying
selection criteria from our pointed RXTE/PCA observations to exclude the
flaring episodes we show that the 150 d period can indeed still be
significantly detected in the hard state. Furthermore, while the ~420 d
timescale associated with the flaring is reduced in the selected hard state
count rate, it is still pronounced in the temporal evolution of the
corresponding hardness ratios. The Ryle radio flux is also consistent with the
150 d period being present but distorted during this time.Comment: 4 pages, 6 figures, to appear in Proceedings of "X-ray Timing 2003:
Rossi and Beyond", ed. P. Kaaret, F.K. Lamb, & J.H. Swan
