TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2486 SUBJECT: GRB 031203: SMARTS optical monitoring DATE: 03/12/11 21:50:29 GMT FROM: Charles Bailyn at Yale/Astro C. Bailyn, P. van Dokkum, M. Buxton, B. Cobb (Yale) and J. S. Bloom (Harvard/CfA) report continued monitoring of the galaxy near the position of GRB 031203 (GCN 2482) with the SMARTS 1.3m telescope + ANDICAM instrument at CTIO: "We have continued SMARTS/ANDICAM observations of the galaxy coincident with the radio position (GCN 2473) of GRB 031203. We are obtaining 42m of exposure time in I and J each night. Our recent I-band data suggest that the galaxy has brightened by 0.09 +/- 0.03 magnitudes over the past 2 nights, reaching I=19.13 in observations beginning Dec. 11 UT=5:27 (in addition to the error in the differential magnitude, there is also an uncertainty of ~0.05 in the absolute magnitude scale). This brightening may mark the emergence of an underlying supernova, so we urge continued observation of this source in all wavelengths."