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We present VLA images and HST/STIS spectra of sources within the center ofthe brightest cluster galaxy (BCG) in Abell 2261. These observations wereobtained to test the hypothesis that its extremely large, flat core reflectsthe ejection of its supermassive black hole. Spectra of three of the four mostluminous "knots" embedded in the core were taken to test whether one mayrepresent stars bound to a displaced massive black hole. The three knots haveradial velocity offsets dV < ~150 km/s from the BCG. Knots 2 and 3 showkinematics, colors, and stellar masses consistent with infalling low-massgalaxies or larger stripped cluster members. Large errors in the stellarvelocity dispersion of Knot 1, however, mean that we cannot rule out thehypothesis that it hosts a high-mass black hole. A2261-BCG has a compact, relicradio-source offset by 6.5 kpc (projected) from the optical core's center, butno active radio core that would pinpoint the galaxy's central black hole to atight 10 GHz flux limit <3.6 uJy. Its spectrum and morphology are suggestive ofan active galactic nucleus that switched off >48 Myr ago, with an equipartitioncondition magnetic field of 15 uG. These observations are still consistent withthe hypothesis that the nuclear black hole has been ejected from its core, butthe critical task of locating the supermassive black hole or demonstrating thatA2261-BCG lacks one remains to be done.

A Radio Relic and a Search for the Central Black Hole in the Abell 2261 Brightest Cluster Galaxy