Back
GCN Circular 20615

Subject
GRB 170205A: Swift/UVOT Detection of a Fading Afterglow
Date
2017-02-06T16:33:17Z (7 years ago)
From
Sam Emery at MSSL-UCL <samuel.emery.15@ucl.ac.uk>
S.W.K. Emery (UCL-MSSL), E. Troja (NASA/GSFC/UMCP) and A.A. Breeveld (UCL-MSSL)  
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 170205A
314 s after the BAT trigger (Troja et al., GCN Circ. 20603Not found
 
 
).
A source consistent with the XRT position
(Beardmore et al. GCN Circ. 20610Not found
 
 
) and also detected by
Guidorzi et al. GCN 20605Not found
 
 
, Butler et al. GCN 20609Not found
 
 
 and Kruehler et al. GCN 20612Not found
 
 

is detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  17:28:40.69 = 262.16955 (deg.)
    Dec (J2000) = -00:03:47.3  =  -0.06313 (deg.)
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).

Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:

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

white(FC)       314             464           147        17.52 +/- 0.04
u(FC)                520             540             19        17.30 +/- 0.22
white             4361           4561          197         20.84 +/- 0.33
v                         619        17292        1101        >20.3
b                         545             565             19         17.79 +/- 0.24
u                      3951        12169          785         20.65 +/- 0.33
w1                     496        10592          924        >20.6
m2                  6287        17909          741        >20.6
w2                  4567        16378        1082        >21.1

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.35 in the direction of the burst
(Schlegel et al. 1998).