TITLE: GCN CIRCULAR NUMBER: 14289 SUBJECT: GRB 130310A: optical observations DATE: 13/03/12 08:00:05 GMT FROM: Antonino Cucchiara at UCSC/UCO Lick A. Cucchiara (UCSC/UCO Lick Observatory), S. B. Cenko (UC Berkeley), D. Perley (Caltech) report on behalf of a large collaboration: "On March 12.4 UT we observed the field of the short-hard GRB 130313A (GCN 14282, 14283, 14284, 14285 and 14288) with the Gemini-South telescope equipped with the GMOS camera. We obtained 5x180s exposures, for a total integration time of 15 minutes (T_mid = T0+1.22 days). A snapshot of our imaging campaign can be seen here: https://www.dropbox.com/s/jqt714c44b7ngei/0310A_rband.jpeg We note the presence of two irregular objects (marked as "G1" adn "G2") within the current XRT error circle (3.6 arcsec radius, GCN 14288). The coordinates of this objects are: "G1" RA: 09:27:36.34 (J2000) Dec: -17:06:18.92 (J2000) "G2" RA: 09:27:36.46 (J2000) Dec: -17:06:13.80 (J2000) Using 3 USNO-B1 stars we estimate a preliminary brightness for "G1" of r' = 25.05 +- 0.15 and for "G2" r'=23.80 +- 0.10. At this point the nature of these objects as well as the relation with GRB 130313A afterglow is still uncertain. Further observations are encouraged. We thank the Gemini staff for performing this observations, in particular J. Thomas-Osip"