[vsnet-grb-info 9450] GRB 100615A: Additional Gemini/NIRI observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10928
SUBJECT: GRB 100615A: Additional Gemini/NIRI observations
DATE:    10/07/02 22:58:46 GMT
FROM:    Daniel Perley at U.C. Berkeley  <dperley at astro.berkeley.edu>

D. A. Perley, J. S. Bloom, S. B. Cenko, and N. R. Butler (UC Berkeley) 
report:

We again observed the field of GRB 100615A (D'Elia et al. 2010, GCN 
10841) using NIRI on Gemini-North between 06:06 and 07:03 on 2010-06-24 
UT, at moderately high airmass.  We acquired 45 images of 60 seconds 
each in the K' filter, a significantly deeper integration than our 
previous observation (Cenko et al., GCN 10861).

A faint object is detected slightly west of the latest online 
UVOT-enhanced XRT error circle, with an aperture magnitude of K' = 21.3 
+/- 0.3 mag.  However, the location of this object is not consistent 
with the improved X-ray localization provided by the Chandra 
observations (Butler et al., GCN 10915).

A very faint possible source is visible at the Chandra location, but it 
is not statistically significant (1.5-sigma).  The 3-sigma limit of the 
image is K' > 22.2 mag; forced photometry gives K' = 23.0 +/- 0.8 mag at 
this location.

An image of the field is posted to:
http://lyra.berkeley.edu/~dperley/100615a/100615a_niri.png