GCN Circular 17120
Subject
GRB 141130A: Swift detection of a burst with an optical counterpart
Date
2014-11-30T23:26:54Z (10 years ago)
From
Scott Barthelmy at NASA/GSFC <scott@milkyway.gsfc.nasa.gov>
A. Vargas (PSU), S. D. Barthelmy (GSFC),
H. A. Krimm (CRESST/GSFC/USRA), D. Malesani (DARK/NBI),
F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL) and
B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:
At 23:10:56 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 141130A (trigger=620090). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 222.814, +47.300 which is
RA(J2000) = 14h 51m 15s
Dec(J2000) = +47d 17' 60"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve shows a single peak
structure with a duration of about 35 sec. The peak count rate
was ~1200 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 23:12:20.3 UT, 84.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source with an enhanced position: RA, Dec
222.8205, 47.3202 which is equivalent to:
RA(J2000) = 14h 51m 16.92s
Dec(J2000) = +47d 19' 12.7"
with an uncertainty of 2.8 arcseconds (radius, 90% containment). This
location is 74 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.82
x 10^20 cm^-2 (Willingale et al. 2013).
The initial flux in the 2.5 s image was 8.27e-10 erg cm^-2 s^-1 (0.2-10
keV).
UVOT took a finding chart exposure of nominal 150.000 seconds with the White
filter starting 93 seconds after the BAT trigger. There is a candidate
afterglow in the list of sources generated on-board at
RA(J2000) = 14:51:17.28 = 222.82199
DEC(J2000) = +47:19:07.5 = 47.31876
with a 90%-confidence error radius of about 1.10 arc sec. This position is 4.1
arc sec. from the center of the XRT error circle. The estimated magnitude is
18.74. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.02.
Burst Advocate for this burst is A. Vargas (avargas AT swift.psu.edu).
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)