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GCN Circular 13911

GRB 121027A: nIR afterglow candidate with AAT
2012-10-27T20:11:13Z (12 years ago)
Rhaana Starling at U of Leicester <>
R.L.C. Starling (U. Leicester), A.J. Levan (U. Warwick), K. Wiersema (U. Leicester), A.R. Lopez-Sanchez (AAO/Macquarie
+University), N.R. Tanvir (U. Leicester), T. Young (ANU), L. Spitler (Macquarie University/AAO) and S. Lee (AAO) report:

We triggered near-infrared observations with IRIS2 on the Anglo-Australian Telescope for GRB 121027A, beginning ~3.5 hours
+after the Swift BAT trigger (Evans et al. GCN Circ. 13907).

The field was observed for 2x10 minutes in each of J, H and K bands. In a preliminary analysis of the K band data (beginning
+13:49 UT) we clearly detect a source within the enhanced XRT error circle ( at position:

RA   04 14 23.44
Dec -58 49 47.4 (J2000)

with approximate magnitude K(AB)=21.10 +/- 0.13.

The source is not discernable from the J and H band images. These, however, do not go as deep owing to variable weather
+conditions; the limiting magnitude in H(AB) is 21.3 (3-sigma, beginning 13:22 UT).

These data were obtained under programme AAT/12B/30.

[GCN OPS NOTE(28oct12): Per author's request, ALG was changed to ARL-S in the author list.]
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