TITLE: GCN CIRCULAR NUMBER: 14634 SUBJECT: GRB 130514A: GROND optical-NIR afterglow discovery and photo-z DATE: 13/05/14 08:40:11 GMT FROM: Alexander Kann 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 GRB 130514A (Swift trigger 555821; E. Sonbas et al., GCN 14632) 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 at 07:15:31 UT on May 14th, 2 minutes after the SWIFT BAT trigger. They were performed at an average seeing of 1" and at an average airmass of 1.18. Inside the 2".6 refined XRT error circle, we detect a source not visible in the DSS or SDSS in all 7 bands. The GROND position for this source is: RA (J2000) = 19:45:07.90 Dec.(J2000) = -07:58:34.4 with an uncertainty of 0".3. Based on the first 4 min of total exposure we estimate preliminary magnitudes (all in AB system) of g' = 22.17 +- 0.09, r' = 19.98 +- 0.01, i' = 19.18 +- 0.02, J = 17.87 +- 0.03, H = 17.26 +- 0.03 and K = 16.81 +- 0.03 We propose this source to be the afterglow of GRB 130514A. Additional evidence is the power-law shape of the SED. The source shows a strong g'-band dropout, we derive a photometric redshift of z = 3.6 +/- 0.2, with an additional small line-of-sight extinction by SMC dust. Given magnitudes are calibrated against SDSS as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.23 mag in the direction of the burst (Schlegel et al. 1998).