The Swift Gamma-Ray Burst Mission Italian site U.K. site

GRB 120811A

Redshift:
Host Galaxy:
Other Observatory Detections:

Time: 02:35:18
Trigger Number: 530581
Burst Advocate: Binbin Zhang

Burst Alert Telescope (BAT):

RA
(J2000)
Dec
(J2000)
90% Error a
Radius
T90 b Fluence c
(15-150 keV)
1-sec Peak d
Photon Flux
(15-150 keV)
Photon Index e
(15-150 keV)
257.184
17:08:44.2
-22.735
-22:44:06.0
2.6 166 11 (1) 1.0 (0.1) 1.95, PL (0.20)

90% error in parentheses,
a arcmin; b seconds; c 10-7 erg/cm2; d ph/cm2/sec; e PL = simple power-law, CPL = cutoff power-law

X-Ray Telescope (XRT):

RA
(J2000)
Dec
(J2000)
90% Error a
Radius
Time to First b
Observation
Early Flux c
(0.3-10 keV)
11 Hour Flux c
(0.3-10 keV)
24 Hour Flux c
(0.3-10 keV)
Initial d
LC Index
Spectral
Index
(Gamma)
Column e
Density
(NH)
17:08:39.70 -22:42:38.0 2.8 n/a n/a 0.08926366 0.052599426 -0.6779 1.99897 8.66874

a arcsec; b seconds; c 10-11 erg/cm2/s; d temporal; e 1021 cm-2

Note: Please be aware that only the very basic temporal and spectral quantities are reported here. You are strongly encouraged to see the referenced GCN circulars for full details.

» XRT GRB Live Catalogue
» XRT Light Curves
» XRT Spectra

UltraViolet/Optical Telescope (UVOT):

RA
(J2000)
Dec
(J2000)
90% Error a
Radius
Time to First b
Observation
Magnitude Other Filter
Magnitudes
n/a n/a n/a 5627 V>19.1 B>20.2
U>20.0
UVW1>19.9
UVW2>19.8
White>20.7

a arcsec; b seconds

Comments:

While the BAT lightcurve and spectral results are consistant with a GRB origin for this trigger, given that the galactic coordinates are (lon,lat)=(0.6,10.3) deg, we cannot rule out a galactic source origin.
XRT: The fact that the XRT source is fading suggests that Swift trigger 530581 is most likely a GRB.
UVOT: no detection

References:

BAT: GCN 13618; GCN 13633
XRT: GCN 13641; Evans et al., 2009, MNRAS, 397, 1177
UVOT: GCN 13641
Radio:
Redshift:
Host:
Other: GCN Report 413.1

BAT Light Curve:

BAT Light Curve for GRBblc/120811A.png