[vsnet-grb-info 11632] GRB 120308A: Further PAIRITEL NIR Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13027
SUBJECT: GRB 120308A: Further PAIRITEL NIR Observations
DATE:    12/03/09 23:18:17 GMT
FROM:    Adam Morgan at U.C. Berkeley  <qmorgan at gmail.com>

A. N. Morgan, and J. S. Bloom (UC Berkeley) report:

We continued to observe the field of GRB 120308A (Baumgartner et al.,
GCN 13017) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona.
The source faded significantly since our first epoch (Morgan et al.,
GCN 13020), suggesting a temporal decay index of approximately 1.0
during our observations.

The preliminary photometry yields:

post burst
t_mid (hr) exp.(hr) filt  mag    m_err
1.55       0.50     J     17.70  0.18
1.55       0.50     H     16.81  0.21
1.55       0.50     Ks    16.00  0.21
5.08       2.09     J     18.92  0.25
5.08       2.09     H     >18.2  3sigUL
5.08       2.09     Ks    >17.3  3sigUL

All magnitudes are given in the Vega system, calibrated to 2MASS. No
correction for Galactic extinction has been made to the above reported
values. No further observations are planned.