GCN Circular 16872
J. Graham (MPE Garching), A. Nicuesa Guelbenzu (TLS Tautenburg), J. Bolmer and J. Greiner (both at MPE Garching) report on behalf of the GROND team: We observed the field of GRB 140930B (Swift trigger 614094; De Pasquale et al., GCN #16857) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at La Silla Observatory (Chile). Observations started at 02:25 UT on 1 October 2014, around 7 hours after the GRB trigger. They were performed at an average seeing of 1.4" and at an average airmass of 1.9. We detect the afterglow candidate reported by Tanvir et al. (GCN #16861) and confirmed by Fong et al. (GCN #16863). At a midtime of 03:00 UT we measure a preliminary AB magnitude of r' = 23.2 +/- 0.2 mag. The analysis of the other GROND photometric bands is still on-going. We note that the photometry is slightly affected by a bright star next to the afterglow. The given magnitude is calibrated against SDSS field stars and not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.04 mag in the direction of the burst (Schlegel et al. 1998).