[vsnet-grb-info 9443] GRB 100702A: Second epoch of Magellan near-IR observations and afterglow limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10921
SUBJECT: GRB 100702A:  Second epoch of Magellan near-IR observations and afterglow limits
DATE:    10/07/02 13:26:12 GMT
FROM:    Edo Berger at Harvard  <eberger at cfa.harvard.edu>

E. Berger, W. Fong, and M. Servillat (Harvard) report:

"We re-observed the location of the short GRB 100702A (GCN 10916) with
the PANIC infrared imager on the Magellan/Baade 6.5-m telescope
starting on 2010 July 2.290 UT (4.8 hours after our first observation,
which started 65 min after the burst; GCN 10919).  A total of 27 min
were obtained in the J-band with slightly worse seeing than in our
first epoch, 0.75 arcsec.  Digital image subtraction of the two epochs
using the ISIS package reveals no change in the flux of our
previously-identified sources S1 (source "B" of Malesani et al. GCN
100918), S2, or S3.  No other variable sources are detected within a
45x45 arcsec region centered on the XRT position to a 5-sigma limit of
J>22.1 mag (Vega).

We note, however, that the bright star at RA = 16:22:47.01, DEC = 
-56:31:53.5 (designated source "A" in GCN 10918) strongly contaminates 
the subtracted image over about 1/4 of the XRT error circle."