GCN Circular 9338
Subject
GRB 090510: NOT afterglow confirmation
Date
2009-05-10T10:30:19Z (15 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@astro.ku.dk>
G. Olofsson, M. Ergon (Univ. Stockholm), D. Malesani, J.P.U. Fynbo
(DARK/NBI), P. Jakobsson (Univ. Iceland), N.R. Tanvir, K. Wiersema
(Univ. Leicester), A.J. Levan (Univ. Warwick), report on behalf of a
larger collaboration:
We observed the field of short Swift/Fermi GRB 090510 (Hoversten et al.,
GCN 9331; Ohno & Pelassa, GCN 9334; Guiriec et al., GCN 9336) with the
Nordic Optical Telescope equipped with ALFOSC. Observations were carried
out in twilight and at high airmass (~3).
The candidate afterglow (Marshall & Hoversten, GCN 9332) is clearly
detected in a stack of our images taken at a mean epoch May 10.215 UT
(4.7 hr after the GRB). Calibrating against closeby USNO stars (R1
magnitudes), we get R ~ 21.2. Comparing this value with the magnitude
reported by Marshall & Hoversten (GCN 9332) indicates fading, thus
confirming that this object is the afterglow of GRB 090510.
Astrometry of the field yields the following coordinates for the
afterglow (0.4" error):
RA(J2000) = 22:14:12.64
Dec(J2000) = -26:35:02.8
which is consistent with the UVOT position. We note the presence of a
fainter source ~1" East of the afterglow. A finding chart is posted at
the following URL:
http://www.astro.ku.dk/~malesani/GRB/090510/090510_finder.png
We acknowledge the observiers at the NOT for carrying out this difficult
observation.
[GCN OPS NOTE(10may09): The authors point out that there is a correction
to the coordinates given above (see GCN Circ 9340).]
