TITLE: GCN CIRCULAR NUMBER: 6368 SUBJECT: GRB070429B: possible host galaxy detection DATE: 07/04/30 01:16:44 GMT FROM: Antonino Cucchiara at PSU Cucchiara A. (PSU), D. B. Fox, S. B. Cenko, E. Berger: We observed the refined XRT error circle of GRB 070429B (GCN 6360) with GMOS on the Gemini-South telescope for a total of 900 sec in r-band starting on 2007 April 29 at 07:59:55 UT (~ 4 hr after the burst). Within the XRT error circle we find a single faint object located at: RA = 21:52:03.96 (J2000) DEC = -38:49:42.79 (J2000) The object appears to be extended and we cannot determine a possible fading at the moment. The r magnitude is 23.18 +- 0.15 calibrated using four stars from USNOB1 catalogue. We thank the Gemini-South staff for their support.