GCN Circular 12760

GRB 111228A: PAIRITEL NIR Detection

A. N. Morgan (UC Berkeley) reports:

We observed the field of GRB 111228A (Ukwatta et al., GCN 12737
Not found
 
 
) with
the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began
at 2011-12-29 06:55:25 UT, ~15.2 hours after the Swift Trigger.  In
mosaics (effective exposure time of 0.46 hours) taken simultaneously
in the J, H, and Ks filters, we marginally detect a source at the
optical afterglow location (Ukwatta et al., GCN 12737
Not found
 
 
; Xin et al., GCN
12738
Not found
 
 
; Klotz et al., GCN 12742
Not found
 
 
; Pandey et al., GCN 12745
Not found
 
 
; Nascimbeni
et al., GCN 12748
Not found
 
 
; Xu et al. GCN 12750
Not found
 
 
; Nysewander et al., GCN 12751
Not found
 
 
;
Kuin & Ukwatta, GCN 12752
Not found
 
 
; Gorosabel et al., GCN 12753
Not found
 
 
; Hentunen et
al., GCN 12754
Not found
 
 
; Sinykov et al., GCN 12756
Not found
 
 
; Guelbenzu et al., GCN
12757
Not found
 
 
).

The preliminary photometry yields:

post burst
t_mid (hr) exp.(hr) filt  mag    m_err
15.56      0.46     J     18.3   0.2
15.56      0.46     H     17.8   0.3
15.56      0.46     Ks    16.2   0.3

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