TITLE: GCN CIRCULAR NUMBER: 10410 SUBJECT: GRB 100206A: Second epoch Gemini-north observations and afterglow limits DATE: 10/02/13 21:24:47 GMT FROM: Edo Berger at Harvard E. Berger and R. Chornock (Harvard) report on behalf of a larger collaboration: "We obtained a second epoch of i-band imaging of the short GRB 100206A (GCN 10376) with GMOS on the Gemini-North 8-m telescope starting on 2010 Feb 12.28 UT. Digital image subtraction of the new observation relative to our previous i-band epoch from 2010 Feb 7.23 UT (GCN 10395) using the ISIS software package does not reveal any fading sources to a 3-sigma limit of i>24.7 mag within the XRT error circle (GCN 10378), in coincidence with the nearby bright galaxy at z=0.41 (GCN 10389), or in coincidence with the nearby fainter galaxy (GCNs 10386,10395). We therefore place a limit of i>24.7 mag on the brightness of the optical afterglow at 15.7 hours after the burst."