[vsnet-grb-info 15494] GRB 140903A: NOT optical and NIR observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16783
SUBJECT: GRB 140903A: NOT optical and NIR observations
DATE:    14/09/05 14:11:50 GMT
FROM:    Dong Xu at DARK/NBI  <dong.dark at gmail.com>

D. Xu (DARK/NBI), S. Geier (NOT), D. Malesani, J. P. U. Fynbo
(DARK/NBI), J. Harmanen (NOT), A. J. Levan (U. Warwick), P. Jakobsson
(U. Iceland) report on behalf of a large collaboration:

We observed the field of the short GRB 140903A (Cummings et al., GCN
16763) using the 2.5m Nordic Optical Telescope (NOT) equipped with
StanCam and NOTCam. We observed for a total of 20 and 30 min in the R-
and H- bands, respectively. The middle times of the observations are
29.898 hr and 30.315 hr after the BAT trigger, respectively.

The previously reported object (Capone et al., GCN 16769; Cenko  et
al., GCN 16770;  Fruchter, GCN 16776; Dichiara et al., GCN 16781) is
clearly detected in our R- and H-band stacked images. We found
R=20.1+/-0.5 mag calibrated with nearby SDSS stars and H=16.1+/-0.3
mag calibrated with the nearby 2MASS stars.

Note that a fuzzy source is present at the same position in the SDSS
field, especially in z-band. Together with the pre- and post-burst
observations, the optical brightness of the object either varies
slowly or remains constant (see also Fruchter, GCN 16776), which
implies that what we're observing in optical is basically the host
galaxy of the burst.