GCN Circular 9093
Subject
GRB 090404: NOT observations
Date
2009-04-05T03:21:10Z (16 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@astro.ku.dk>
D. Malesani, J.P.U. Fynbo (DARK/NBI), P. Jakobsson (Univ. Iceland), A.J.
Levan (Univ. Warwick), T. Liimets (Tartu Obs. and NOT), and Z. Banhidi
(NOT), report on behalf of a larger collaboration:
We observed the field of GRB 090404 (Ziaeepour et al., GCN 9086) with
the NOT equipped with StanCam. Observations were carried out in the R
and I bands, starting on 2009 Apr 5.035 UT (8.89 hr after the GRB). A
total of 20 min exposure per filter were secured.
We do not detect any object inside the revised XRT error circle
(Beardmore et al., GCN 9088), down to limiting magnitudes R > 23.5, I >
22.3, assuming R = 19.19 and I = 18.84 for the USNO-B1 star 1255-0233978
at RA = 15:57:00.24, Dec = +35:31:28.0.
We note the presence of a faint object (R = 22.8), possibly extended,
just outside the XRT circle, at coordinates (J2000):
RA = 15:56:57.72
Dec = +35:30:58.2
This position is 2.4" away from the XRT error circle center, which has
currently an error radius of 1.4" (from
http://www.swift.ac.uk/xrt_positions/index.php). We cannot state whether
this object is related to GRB 090404. Further observations are ongoing.
[GCN OPS NOTE(06may09): Per author's request, the institutional
affiliation of Banhidi was changed to NOT.]