TITLE: GCN CIRCULAR NUMBER: 14655 SUBJECT: GRB 130515A: GROND Observations DATE: 13/05/15 06:01:37 GMT FROM: Sebastian Schmidl at TLS Tautenburg S. Schmidl, D. A. Kann (both TLS Tautenburg) and J. Greiner (MPE Garching) report on behalf of the GROND team: We observed the field of the short GRB 130515A (Swift trigger 555880; Malesani et al., GCN 14650) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla Observatory (Chile). Observations started as soon as the position became visible above the pointing limit, at 02:12:08 UT on May 15th, 51 minutes after the BAT trigger. They were performed at an average seeing of 1".6 and at an average airmass of 2.4. Inside the 2".9 SPER XRT error circle (RA = 18:53:45.79, Dec. -54:16:45.2), we detect a faint source, and additionally a significantly brighter, possibly extended source on the western edge of the XRT error circle. We find the following positions (J2000) for these sources: In the error circle: RA = 18:53:45.79, Dec. = -54:16:47.3 On the western edge: RA = 18:53:45.24, Dec. = -54:16:44.5 with an error of 0".5 in each case. Based on an observation with 780 s integration time in g'r'i'z' and 720 s integration time in JHK, centered at 0.043586 days after the trigger, we estimate preliminary magnitudes 3-sigma upper limits (all in AB system) of g' > 23.86, r' = 22.55 +/- 0.15, z' = 21.17 +/- 0.11, J = 19.74 +/- 0.27, H > 19.4 and K > 19.1 for the object inside the error circle, and g' = 22.12 +/- 0.08., r' = 20.68 +/- 0.03., z' = 19.51 +/- 0.03., J = 18.50 +/- 0.09, H = 18.45 +/- 0.14 and K = 18.47 +/- 0.17 for the possible galaxy on the western edge. Given magnitudes are calibrated against GROND zero points (g'r'i'z') as well as 2MASS field stars (JHK) and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.07 mag in the direction of the burst (Schlegel et al. 1998).