| Summary table |
|---|
| Variable |
Value |
Source |
| T0 |
13:23:45 UTC |
GCN_circulars,INTEGRAL |
| ra |
255.2708° |
IPN |
| decl |
-40.5167° |
IPN |
| pos_error |
3.33e-02° |
IPN |
| GBM_located |
False |
|
| mjd |
56160.55815972222 |
GCN_circulars,INTEGRAL |
| IPN table |
|---|
| GRB_name |
GRB120821A |
| ra |
255.2708° |
| decl |
-40.5167° |
| pos_error |
3.33e-02° |
| GCN 13696 table |
|---|
| GRB_name |
GRB120821A |
| GCN_number |
13696 |
| Detection_method |
INTEGRAL |
| t_trigger |
13:23:45 UTC |
| ra |
255.2692° |
| decl |
-40.5212° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 13696
SUBJECT: GRB 120821A: a long GRB detected by INTEGRAL
DATE: 12/08/21 14:47:21 GMT
FROM: Sandro Mereghetti at IASF/CNR
S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, R.Boissay
(ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of the IBAS
Localization Team report:
a long gamma ray burst lasting about 12 s has been detected by IBAS in the
IBIS/ISGRI data at 13:23:45 UT of August 21
Its refined coordinates (J2000) are:
RA: 255.2692 [degrees]
DEC: -40.5212 [degrees]
with an uncertainty of 2 arcmin (90% c.l.).
The burst has a fluence of about 3e-7 erg/cm2 (20-200 keV)
A plot of the light curve will be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html
=====================================================================
Sandro Mereghetti INAF - Istituto di Astrofisica Spaziale
e Fisica Cosmica - Milano
Tel. +39-02-23699323
Fax +39-02-2666017 via Bassini 15, I-20133 Milano, ITALY
sandro@iasf-milano.inaf.it
http://www.iasf-milano.inaf.it/~sandro/personal.html
===========================================================================
|
| GCN 13697 table |
|---|
| GRB_name |
GRB120821A |
| GCN_number |
13697 |
| Detection_method |
GROND |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 13697
SUBJECT: GRB 120821A: GROND upper limits
DATE: 12/08/22 09:47:54 GMT
FROM: Patricia Schady at MPE/Swift
P. Schady (MPE Garching), S. Klose (TLS Tautenburg) and J. Greiner (MPE
Garching) report on behalf of the GROND team:
We observed the field of GRB 120821A (INTEGRAL trigger #6266; Mereghetti
et al., GCN #13696) simultaneously in g'r'i'z'JHK with GROND (Greiner et
al. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La
Silla Observatory (Chile).
Observations started at 23:47 UT, 10.4 hours after the GRB trigger. They
were performed at an average seeing of 1.1" and at an average airmass of
1.0.
The GROND JHK observations fully covered the INTEGRAL error circle,
whereas the g'r'i'z observations covered ~60% of the error circle. We do
not detect any obvious new source brighter than the detection limits of
DSS2 and 2MASS within the area covered by the 2arcmin INTEGRAL error
circle.
|
| GCN 13698 table |
|---|
| GRB_name |
GRB120821A |
| GCN_number |
13698 |
| Detection_method |
Swift-UVOT Other |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 13698
SUBJECT: GRB 120821A: Swift/UVOT Upper Limits
DATE: 12/08/22 11:38:06 GMT
FROM: Samantha Oates at MSSL
S. R. Oates (MSSL-UCL) and P. D'Avanzo (INAF-OAB)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 120821A
15ks after the INTEGRAL trigger (Mereghetti et al., GCN Circ. 13696).
No optical afterglow consistent with the INTEGRAL position
(Mereghetti et al., GCN Circ. 13696) 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 initial exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
u 17059 17241 179 >20.92
w1 16153 17053 886 >21.7
m2 15246 16146 886 >21.6
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 25.4 in the direction of the burst
(Schlegel et al. 1998).
|
| GCN 13699 table |
|---|
| GRB_name |
GRB120821A |
| GCN_number |
13699 |
| Detection_method |
Swift-XRT Other |
| ra |
255.2576° |
| decl |
-40.5136° |
| Circular_text |
TITLE: GCN CIRCULAR
NUMBER: 13699
SUBJECT: GRB 120821A: Swift/XRT observations
DATE: 12/08/22 12:05:46 GMT
FROM: Paolo D'Avanzo at INAF-OAB
P. D'Avanzo, A. Melandri, S. Campana (INAF-OAB) report on behalf of the
Swift team:
The Swift XRT observed the error circle of the INTEGRAL-detected GRB
120821A (Mereghetti et al, GCN Circ. 13696) from 15.2 to 17.2 ks after the
trigger. The data comprise 2.0 ks of Photon Counting (PC) mode data. No
clear afterglow candidate is detected. We note however the presence of a
very faint and low-significance source within the INTEGRAL error circle
(Mereghetti et al, GCN Circ. 13696) at the following position: RA, Dec
=255.25762, -40.51365 which is equivalent to:
RA (J2000): 17h 01m 01.83s
Dec (J2000): -40d 30' 49.1"
with an uncertainty of 6.7 arcsec (radius, 90% confidence).
The source has a count rate of (4.5 +/- 2.1) x 10^-3 cts/s. This
corresponds to an observed 0.3-10 keV flux of (2.7 +/- 1.2) x 10^-13
erg/cm2/s (assuming a typical GRB spectrum with photon spectral index of
2). If we consider the Galactic absorption in this direction (1.1 x 10^22
cm^-2; Kalberla et al. 2005) this corresponds to an unabsorbed flux of
(5.5 +/- 2.5) x 10^-12 erg/cm2/s. Given the limited statistics, it is not
possible to determine whether the source is fading.
|