GCN Circular 14086

Subject

GRB 121209A: Swift/UVOT Upper Limits

Event

Date

2012-12-14T17:19:02Z (13 years ago)

From

Stefan Immler at NASA/GSFC <stefan.m.immler@nasa.gov>

S. Immler (NASA/CRESST/GSFC) and A. Maselli (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 121209A
96 s after the BAT trigger (Maselli et al., GCN Circ. 14045Loading...
 
 ).
No optical afterglow consistent with the optical position (Kruehler
et al. GCN Circ. 14049Loading...
 
 ) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            96          246          147         >21.4
white               96        12808         1217         >21.7
v                 5857        35749         1967         >20.3
b                 5241        24926         1784         >21.1
u                  308        30697         1959         >21.6
w1                6267        29936         1968         >21.5
m2                6062        36468         2314         >22.3
w2                5652        34835         1968         >21.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).