TITLE:   GCN CIRCULAR
NUMBER:  17255
SUBJECT: GRB 141230A: Nanshan optical obsrvations
DATE:    14/12/30 15:36:22 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark@gmail.com>

D. Xu (DARK, NAOC), H.-B. Niu, A. Esamdin, L. Ma (XAO) report:

We observed the field of iPTF14jko (Singer et al., GCN 17254), a
candidate optical afterglow of GRB 141230A (Fermi trigger 441602665 /
bn141230142), using the 1m telescope located at Nanshan, Xinjiang,
China. We obtained 2x120s R-band images at 13:40 UT on 2014-12-30
(i.e., ~10.3 hr post-burst).

A source is detected at the iPTF14jko position with m(R)=19.53+/-0.28
(Vega), calibrated with nearby SDSS stars. The source basically
remains constant compared with the early (129.9 min post-burst)
measurement in GCN 17254, which indicates that it is unlikely the
optical afterglow of GRB 141230A, according to the decaying behavior
of conventional GRB optical light curves.