TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2456 SUBJECT: GRB031111A, prompt optical observations DATE: 03/11/28 12:41:15 GMT FROM: Rene Hudec at AIO Martin Jelinek, Petr Kubanek, Martin Nekola, Rene Hudec & BART team, Astronomical Institute Ondrejov, report: Robotic system BART (Ondrejov Observatory) observed the error box of GRB031111A (HETE 2924) using its two WF cameras only 30s after receiving the coordinates. Overall time since GRB was 70 minutes. Most of the obtained images were overexposed due to nearby moon, but at images taken at 2003 Nov 11, 3h20, 3h56, 4h02, 4h08 and 4h14 after burst, no new object in comparison with GSC was identified; we estimate the limiting magnitude I about 13 within the combined HETE/IPN error box (cf. GCN 2443). The corresponding image is posted at http://lascaux.asu.cas.cz/~mates/031111A.jpg