A Search for the Optical Counterpart of the Luminous X-Ray Source in NGC 6652

We examine images of the field of X1832-330, the luminous (Lx ~ 10^36 erg/s)X-ray burst source near the center of the globular cluster NGC 6652, in orderto identify the optical counterpart for further study. U and B ground-basedimages allow us to set a limit M_B > 3.5 for the counterpart at the time ofthose observations, provided that the color is (U-B)_0 ~ -1, similar to thesources known in other clusters. Archival Hubble Space Telescope observationssurvey most but not all of the 1 sigma X-ray error circle, and allow us to setlimits M_B > 5.9 and M_B > 5.2 in the WF/PC and WFPC2 regions, respectively. Inthe WF/PC images we do weakly detect a faint object with UV-excess, but it islocated 11.7'' from the ROSAT X-ray position. This considerable (2.3 sigma)discrepancy in position suggests that this candidate be treated with caution,but it remains the only reasonable one advanced thus far. We measure for thisstar m_439 = 20.2 +- 0.2, (m_336 - m_439) = -0.5 +- 0.2, and estimate M_B =5.5, (U-B)_0 = -0.9, similar to other known optical counterparts. If thiscandidate is not the identification, our limits imply that the truecounterpart, not yet identified, is probably the optically-faintest clustersource yet known, or alternatively that it did not show significant UV excessat the time of these observations. Finally, we assess the outlook for theidentification of the remaining luminous globular cluster X-ray sources.