A possible optical counterpart for the triple pulsar system PSR B1620-26

We have searched deep optical images of the globular cluster M4 for a possible optical counterpart for the third body in the PSR B1620-26 system. We identify as a possible optical counterpart a star located within $0.3''$ of the nominal pulsar position with $Vapprox 20$. This magnitude is consistent with a main sequence cluster member with $Mapprox 0.45M_odot$. However, this star may be blended with fainter stars, and the probability of a chance superposition is non-negligible.Comment: 8 pages in uuencoded compressed postscript, to appear in ApJ Letters, Yale Preprint 25-07-9