[vsnet-grb-info 12876] GRB 130215A: GROND Detection of the Optical/NIR Afterglow

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14221
SUBJECT: GRB 130215A: GROND Detection of the Optical/NIR Afterglow
DATE:    13/02/16 03:38:47 GMT
FROM:    Fabian Knust at MPE/GROND  <fabian.knust at hotmail.de>

F. Knust, K. Varela, J. Greiner (all MPE Garching), and D. A. Kann (TLS Tautenburg) report on behalf of the GROND team:

We observed the field of GRB 130215A (Swift trigger 548760; D'Elia et al., GCN 14204) 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 00:50 UT on 16.02.13, 23.3 hrs after the GRB trigger They were performed at an average seeing of 1".8 and at an average airmass of 1.98.

We detect a point source in most bands at position:

RA (J2000.0) = 02:54:00.70

Dec. (J2000.0) = +13:23:43.4

with an uncertainty of 0".4, close to the position reported by Zheng et al. (GCN 14205).

Based on the first 13 min of total exposures in g'r'i'z' and 14 min in JHK, we estimate preliminary magnitudes (all in AB system) of

g' = 21.0 +- 0.1 mag,

r' = 20.5 +-0.1 mag,

i' = 20.2 +- 0.1 mag,

z' = 19.9 +- 0.1 mag,

J = 19.4 +- 0.2 mag,

H = 19.0 +- 0.1 mag

and

K > 18.0 mag.

Given magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.16 mag in the direction of the burst (Schlegel et al. 1998).