GCN Circular 7984
Subject
GRB 080714: GROND confirmation of the optical/NIR afterglow
Date
2008-07-16T06:43:03Z (16 years ago)
From
Thomas Kruehler at MPE/MPI <kruehler@mpe.mpg.de>
T. Kruehler, J. Greiner, C. Clemens, A. Yoldas (all MPE Garching), A.
Kupcu Yoldas (ESO) and G. Szokoly (Eoetvoes Univ., Budapest) report on
behalf of the GROND team:
We observed the field of GRB 080714 (Swift trigger 316910; M. Perri et
al., GCN #7978) in two epochs, simultaneously in g'r'i'z'JHK with GROND
(Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m ESO/MPI telescope
at La Silla Observatory (Chile).
We detect the optical afterglow reported by Marshall & Perri (GCN #7982) at
RA (J2000.0) = 13h 32m 25.49s
DEC (J2000.0) = -60d 16' 39.3"
with an absolute uncertainty of 0.6".
Preliminary photometry yields the following magnitudes against USNO-B1 and
2MASS field stars in stacked images:
Band T_mid(h) Exp(min) Mag
g' 6.4058 50 > 24.3
g' 30.3847 32 > 23.4
r' 6.4058 50 22.76 +- 0.08
r' 30.3847 32 > 23.6
i' 6.4058 50 21.15 +- 0.07
i' 30.3847 32 22.68 +- 0.24
z' 6.4058 50 20.39 +- 0.06
z' 30.3847 32 21.82 +- 0.29
J 6.2827 40 18.58 +- 0.11
J 30.2958 30 20.00 +- 0.16
H 6.2827 40 17.25 +- 0.14
H 30.2958 30 18.52 +- 0.24
not corrected for the expected Galactic foreground reddening of around
E(B-V) = 1.15 mag (Schlegel et al., 1998).
Given the high foreground extinction, the non detection in g' is
consistent with the powerlaw slope of the broad band SED derived from r to
H and does not necessarily imply a high redshift.
Additionally, we note the presence of a nearby, faint (r'~ 24.1 +- 0.2)
source at
RA (J2000.0) = 13h 32m 25.60s
DEC (J2000.0) = -60d 16' 37.7"
roughly 1.8" away from the afterglow, which may influence the photometry
in the second epoch.