GCN Circular 7984

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
Not found
 
 
) 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
Not found
 
 
) 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.