TITLE: GCN CIRCULAR NUMBER: 6122 SUBJECT: GRB 070220: ART-3 Optical and NIR limits DATE: 07/02/21 07:53:10 GMT FROM: Ken ichi Torii at Osaka U K. Torii, S. Tanaka, and H. Tsunemi (Osaka U.) report: The error region of GRB 070220 (Stamatikos et al. GCN 6114; Beardmore et al. GCN 6118) was observed with the 14 inch ART-3a and 0.35 m ART-3b, both located in Toyonaka, Osaka. The imaging started at 2007 Feb. 20, 09:27:03 UT (4.7 hours after the burst) in Ic band (ART-3a), and at 09:55:44 UT in J band (ART-3b equipped with thermoelectrically cooled InGaAs array). We do not detect neither optical nor near infrared counterpart for the X-ray afterglow (GCN 6114, 6118), and derive the following 3 sigma upper limits relative to USNO-B1.0 I2 and 2MASS J magnitudes. ----------------------------------------- StartUT Filter Limit Exposure ========================================= 09:53:18 Ic 19.4 60s x 75 09:55:44 J 14.4 20s x 200 11:12:03 Ic 19.4 60s x 100 =========================================