TITLE:   GCN CIRCULAR
NUMBER:  13893
SUBJECT: GRB 121024A: PAIRITEL NIR Detection
DATE:    12/10/24 19:52:45 GMT
FROM:    Adam Morgan at U.C. Berkeley  <qmorgan@gmail.com>

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

We observed the field of GRB 121024A (Pagani et al., GCN 13886) with
the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began
at 2012-Oct-24 07h31m47s UT, ~4.6 hours after the Swift Trigger.  In
mosaics (effective exposure time of 0.46 hours) taken simultaneously
in the J, H, and K filters, we detect a source at the optical
afterglow location (Pagani et al., GCN 13886; Klotz et al., GCN 13887;
Jelinek et al., GCN 13888; LaCluyze et al., GCN 13889; Knust et al.
GCN 13891).

The preliminary photometry yields:

post burst
t_mid (hr) exp.(hr) filt  mag    m_err
6.06       0.46     J     >18.4  3sig
6.06       0.46     H     17.1   0.2
6.06       0.46     Ks    >16.2  3sig

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