THE STRANGE CASE OF THE X-RAY BINARY 2129+47

Spectroscopic and photometric observations of 2129 + 47 in its extended quiescent state confirm the lack of measurable ellipsoidal and radial-velocity variations of the F8 IV star which now dominates the optical light. A possible, low-amplitude velocity change in Hβ absorption might indicate that the secondary star in the 5.2 hr binary still contributes slightly to the spectrum. The distance of the F8 IV star is found to be ∼6-8 kpc, making the x-ray source considerably more luminous than previously estimated, if it is at the same distance (i.e., a physical companion).