TITLE:   GCN CIRCULAR
NUMBER:  10861
SUBJECT: GRB 100615A: Gemini/NIRI Observations
DATE:    10/06/16 17:04:00 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko@srl.caltech.edu>

S. B. Cenko, D. A. Perley (UC Berkeley), N. R. Tanvir (U. Leicester), A.
J. Levan (U. Warwick), J. S. Bloom, B. E. Cobb (UC Berkeley), K. Wiersema
(U. Leicester) report on behalf of a larger collaboration:

We have imaged the field of GRB100615A (D'Elia et al., GCN 10841) with the
Near InfraRed Imager on the 8-m Gemini North telescope.  Observations were
obtained in the J and K filters beginning at 7:36 UT on 15 June 2010 (~
5.5 hours after the trigger).

We find no sources inside the revised XRT error circle (Goad et al., GCN
10848) to limiting magnitudes of J > 22.1, K > 20.9 (Vega, calibrated with
respect to 2MASS).  Combined with additional limits from other facilities
(Dhillon et al., GCN 10842; Morgan et al., GCN 10843; Nicuesa et al., GCN
10844; Holland and D'Elia, GCN 10856), and the large excess X-ray column
derived from XRT observations (Margutti et al., GCN 10847), we conclude
that GRB100615A is likely a highly extinguished event.