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GCN Circular 13403

GRB 120630A: NOT optical source within the XRT error circle
2012-07-02T09:24:21Z (12 years ago)
Dong Xu at Weizmann Inst <>
D. Xu (WIS), L.-P. Xin (NAOC), D. Malesani, J. P. U. Fynbo (DARK/NBI),
S. Geier (NOT) report on behalf of a larger collaboration,

Using the 2.5m Nordic Optical Telescope (NOT) equipped with StanCam,
we observed GRB 120630A (distributed by Swift PI: Neil Gehrels) whose
initial XRT localization/position was determined as

RA(J2000) =    23h 29m 10.6s
Dec(J2000) =   42d 33m 14.1s

with an uncertainty of 10 arcsec radius. Observations started at
03:06:20 UT on 2012-07-02 (i.e., 27.8 hr since the BAT trigger) and
5x360s R-band frames were obtained.

Within the XRT error circle, an optical source is clearly detected in
the stacked image at coordinates

RA(J2000) =    23h 29m 10.23s
Dec(J2000) =   42d 33m 13.0s

with an uncertainty of 0.5 arcsec radius. The source had R=22.53 +/-
0.15 mag, calibrated with nearby USNO stars with R2 magnitudes.
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