A Cessation of X‐Ray Dipping Activity in X1254−690

We present results from a campaign of simultaneous X-ray and opticalobservations of X1254-690 conducted using the Rossi X-ray Timing Explorer andthe CTIO 1.5m telescope. We find that the usually-observed deep X-ray dippingis not seen during the times of our observations, with an upper limit of ~2% onany X-ray orbital variation, and that the mean optical variability has declinedin amplitude from 0.40+-0.02 mag (in V) to 0.28+-0.01 mag. These findingsindicate that the vertical structure on the disk edge associated with theimpact point of the accretion stream has decreased in angular size from 17-25degrees to <10 degrees, and support the suggestions of previous modeling workthat the bulge provides 35-40% of the contribution to the overall opticalmodulation. The average optical and X-ray brightnesses are comparable to theirvalues during dipping episodes, indicating that the mean accretion rate anddisk radius remain unchanged.Comment: 6 pages, 3 figures, accepted for publication in Ap