[vsnet-grb-info 12635] GRB 121125A: LOAO Observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13995
SUBJECT: GRB 121125A: LOAO Observation
DATE:    12/11/25 16:47:57 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim at astro.snu.ac.kr>

M. Im (CEOU/SNU) and Y. Urata (NCU) on behalf of EAFON.

  We observed the field of GRB 121125A 
(Barlow et al., GCN 13993) in B and R filters using 
the 1-m telescope at Mt. Lemmon observatory in Arizona, US.

  The observation started at 2012-11-25 12:24:27 UT, 
or about 3.87 hours after the BAT alert, and continued for
about 30 min. We identify an object in stacked images of 
both B and R at

  RA=15:14:06.586, Dec=55:18:47.95 with rms error of 0.6".

  This is consistent with the UVOT coordinate of
the afterglow candidate reported in Barlow et al.
  The object has R-band magnitude of R = 19.29 +- 0.14 mag,
calibrated against R2 magnitude (16.13 mag) of a USNO-B1 star 
at RA=15:14:07.14, Dec=+55:18:40.30. Combined with the result
from Yurkov et al. (GCN 13994) and Barlow et al., our result
reveals a fading behavior of the object, thus we identify 
the object to be the afterglow of GRB 121125A.

  We thank the LOAO operator, Jae-Hyuk Yoon for performing 
the observation.