TITLE: GCN CIRCULAR NUMBER: 14173 SUBJECT: GRB 130131B: GROND Upper limits DATE: 13/02/01 14:07:31 GMT FROM: Karla Varela at MPE F.Knust, K.Varela, J.Greiner (all MPE Garching) report on behalf of the GROND team: We observed the field of GRB 130131B (Swift trigger 547420; Siegel et al., GCN 14159) simultaneously in g'r'i'z'JHK 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 at 04:00 UT on February 1st, 9 hrs after the GRB trigger, only 27 deg away from the moon. They were performed at an average seeing of 2.9��� and at an average airmass of 1.6. We do not detect a source within the Swift-XRT error circle reported by Goad et al. (GCN 14165) down to 3-sigma AB limiting magnitudes g' > 23.4, r' > 23.7, i' > 23.4, z' > 23.3, J > 21.2, H > 20.5 and K > 19.7 The given limits are derived based on calibrating the images against GROND zeropoints in g'r'i'z' and 2MASS field stars in JHK and are not corrected for the Galactic foreground extinction corresponding to a reddening of E_(B-V)= 0.03mag in the direction of the burst (Schlegel et al. 1998).