TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2498 SUBJECT: GRB 031220 : Kyoto Optical Observation DATE: 03/12/21 08:48:27 GMT FROM: Hitoshi Yamaoka at Kyushu U., VSNET-GRB collab. M. Uemura, R. Ishioka, T. Kato (Kyoto U.), C. Nakayama and H. Yamaoka (Kyushu U.) report on behalf of VSNET-GRB collaboration: "We observed the position of GRB 031220 (=H2976) starting at Dec. 20.39 UT (6.0 hours after burst) with the 0.25-m telescope (+unfiltered CCD) at Kyoto University. The stacked image (32 x 30s, during 09:43 - 10:07 UT) covers the central part (about 45%) of the entire SXC error box. Visual comparison of the stacked image to the DSS 2 red image shows no new object down to a limiting magnitude of about 17.8 (estimated with USNO-A2.0 red magnitudes of many field stars). This message can be cited."