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GCN Circular 11519

GRB 101225A: Host galaxy
2011-01-05T13:44:53Z (13 years ago)
Dong Xu at Weizmann Inst <>
D. Xu (Weizmann Inst.), D. Malesani, J.P.U. Fynbo, J. Hjorth
(DARK/NBI), P. Jakobsson (U. Iceland), T. Augusteijn (NOT), report on
behalf of a larger collaboration:

We imaged the field of GRB 101225A (Racusin et al., GCN 11493) at the
Nordic Optical Telescope (NOT) equipped with ALFOSC. We obtained 6x600
s R-band images with a good seeing ~0.7" and little cloud cover.
Observations started at 20:55:25 UT on 2011 Jan 4 (i.e., 10.1 days
after the BAT trigger).

The optical counterpart of the burst (Xu et al., GCN 11495) has faded
further and it is detected in the stacked image with R = 24.1+/-0.1,
calibrated against the USNO-B1 star #1345-0000324. The object is now
significantly extended along the northwest-southeast direction,
indicating a significant contribution from the underlying host galaxy.

Further observations are encouraged, especially in the NIR.
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