[vsnet-grb-info 20049] GRB 171120A: Swift/UVOT Upper Limits

GCN Circulars gcncirc at capella2.gsfc.nasa.gov
Wed Nov 22 06:21:44 JST 2017


TITLE:   GCN CIRCULAR
NUMBER:  22144
SUBJECT: GRB 171120A: Swift/UVOT Upper Limits
DATE:    17/11/21 21:21:20 GMT
FROM:    Jeffrey Gropp at PSU  <jdg44 at psu.edu>

J. D. Gropp (PSU) and A. Tohuvavohu (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 171120A
99 s after the BAT trigger (Tohuvavohu et al., GCN Circ. 22133).
No optical afterglow consistent with the refined XRT position
(Evans et al. GCN Circ. 22135)
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            99          249          147         >19.9
u_FC               311          561          246         >19.7
white               99         5989          560         >21.1
v                  640         6399          413         >19.1
b                  566         5784          413         >20.9
u                  311        11713          811         >20.7
w1                5174        11532         1082         >21.0
m2                9724        10624          886         >21.0
w2                4559         6194          393         >21.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).



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