TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1840 SUBJECT: GRB030131: Optical limit DATE: 03/01/31 14:53:46 GMT FROM: Derek Fox at CIT P.A. Price (RSAA/ANU) and D.W. Fox (Caltech) report on behalf of a larger collaboration: "We have imaged the full localization region of GRB030131 (GCN 1838) with the Palomar 48-inch Oschin Telescope + NEAT camera, in six 120s exposures over 10:42 UT to 11:31 UT. The summed image from these unfiltered exposures reaches a limiting magnitude of R~21 mag as estimated from the magnitude of several USNO-A2.0 stars in the image. We identify no new sources by reference to images from the Second Digitized Sky Survey. We estimate the magnitude of any new source to be R>20 mag at the mean epoch of our observations, 11:16 UT, which is 3.62 hours after the burst."