Gamma-ray Burst 110708A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Fri 08 Jul 11 04:43:54 UT
NOTICE_TYPE:    INTEGRAL Wakeup
TRIGGER_NUM:    6315,   Sub_Num: 1
GRB_RA:         340.0790d {+22h 40m 19s} (J2000),
                340.1966d {+22h 40m 47s} (current),
                339.5698d {+22h 38m 17s} (1950)
GRB_DEC:        +53.9481d {+53d 56' 53"} (J2000),
                +54.0084d {+54d 00' 30"} (current),
                +53.6868d {+53d 41' 12"} (1950)
GRB_ERROR:      2.93 [arcmin, radius, statistical only]
GRB_INTEN:      11.17 [sigma]
GRB_TIME:       17023.99 SOD {04:43:43.99} UT
GRB_DATE:       15750 TJD;   189 DOY;   11/07/08
SC_RA:          345.84 [deg] (J2000)
SC_DEC:          64.06 [deg] (J2000)
SUN_POSTN:      107.04d {+07h 08m 09s}  +22.51d {+22d 30' 47"}
SUN_DIST:        90.90 [deg]   Sun_angle= 8.5 [hr] (West of Sun)
MOON_POSTN:     191.67d {+12h 46m 40s}  -10.34d {-10d 20' 11"}
MOON_DIST:      129.66 [deg]
GAL_COORDS:     104.30, -4.11 [deg] galactic lon,lat of the burst
ECL_COORDS:      13.97, 55.24 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Possibly real GRB event

red DSS finding chart ps-file

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Fri 08 Jul 11 04:46:54 UT
NOTICE_TYPE:    INTEGRAL Refined
TRIGGER_NUM:    6315,   Sub_Num: 2
GRB_RA:         340.0816d {+22h 40m 20s} (J2000),
                340.1992d {+22h 40m 48s} (current),
                339.5724d {+22h 38m 17s} (1950)
GRB_DEC:        +53.9460d {+53d 56' 46"} (J2000),
                +54.0063d {+54d 00' 23"} (current),
                +53.6847d {+53d 41' 05"} (1950)
GRB_ERROR:      2.72 [arcmin, radius, statistical only]
GRB_INTEN:      15.95 [sigma]
GRB_TIME:       17054.81 SOD {04:44:14.81} UT
GRB_DATE:       15750 TJD;   189 DOY;   11/07/08
SC_RA:          345.84 [deg] (J2000)
SC_DEC:          64.06 [deg] (J2000)
SUN_POSTN:      107.04d {+07h 08m 10s}  +22.51d {+22d 30' 46"}
SUN_DIST:        90.90 [deg]   Sun_angle= 8.5 [hr] (West of Sun)
MOON_POSTN:     191.70d {+12h 46m 47s}  -10.35d {-10d 20' 49"}
MOON_DIST:      129.66 [deg]
GAL_COORDS:     104.30, -4.11 [deg] galactic lon,lat of the burst
ECL_COORDS:      13.97, 55.24 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       Possibly real GRB event

GCN NOTICE

TITLE:          GCN/INTEGRAL NOTICE
NOTICE_DATE:    Fri 08 Jul 11 07:12:33 UT
NOTICE_TYPE:    INTEGRAL Offline
TRIGGER_NUM:    6315,   Sub_Num: 3
GRB_RA:         340.1207d {+22h 40m 29s} (J2000),
                340.2383d {+22h 40m 57s} (current),
                339.6112d {+22h 38m 27s} (1950)
GRB_DEC:        +53.9597d {+53d 57' 35"} (J2000),
                +54.0200d {+54d 01' 12"} (current),
                +53.6983d {+53d 41' 54"} (1950)
GRB_ERROR:      1.60 [arcmin, radius, statistical only]
GRB_INTEN:      16.00 [sigma]
GRB_TIME:       17054.81 SOD {04:44:14.81} UT
GRB_DATE:       15750 TJD;   189 DOY;   11/07/08
SC_RA:          345.84 [deg] (J2000)
SC_DEC:          64.06 [deg] (J2000)
SUN_POSTN:      107.14d {+07h 08m 35s}  +22.50d {+22d 30' 05"}
SUN_DIST:        90.93 [deg]   Sun_angle= 8.5 [hr] (West of Sun)
MOON_POSTN:     193.06d {+12h 52m 14s}  -10.86d {-10d 51' 33"}
MOON_DIST:      129.59 [deg]
GAL_COORDS:     104.33, -4.11 [deg] galactic lon,lat of the burst
ECL_COORDS:      14.01, 55.23 [deg] ecliptic lon,lat of the burst
COMMENTS:       INTEGRAL GRB Coordinates.  
COMMENTS:       refined_coordinates_after_offline_analysis

GCN Circular #12112
D.Gotz (CEA-Saclay), S.Mereghetti, A.Paizis (IASF-Milano), J. Borkowski (CAMK, Torun), E. Bozzo, C.Ferrigno, M. Beck, V. Savchenko (ISDC, Versoix), on behalf of the IBAS Localization Team report:
a gamma ray burst lasting about 50 s has been detected by IBAS in the IBIS/ISGRI data at 04:43:22 U.T. of July 8.
Its refined coordinates (J2000) are:
```
   RA:  340.1208 [degrees]
   DEC: +53.9597 [degrees]
```
with an uncertainty of 1.6 arcmin (90% c.l.).
A preliminary analysis gives a 20-200 keV peak flux of about 0.8 ph/ cm2 s (2 s integration time), and a fluence of about 2e-6 erg/cm2.
A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html This message can be cited.
GCN Circular #12115
FROM: Valerio D'Elia at ASDC
V. D'Elia, G. Stratta (ASDC) and J. Cannizzo (GSFC) report, on behalf of the Swift team:
Swift XRT began a 5ks target of opportunity observation of the field =20 of INTEGRAL burst GRB 110708A (Gotz et al., GCN circ 12112) on 14:25:40 UT, 34.9 =20 ks after the burst trigger. In the first 4.6 ks of data, we detect a source, located at RA, Dec 340.11178, 53.96182 which is equivalent to:
```
 RA(J2000) = 22h 40m 26.82s
 Dec(J2000) = +53d 57' 42.5"
```
with an uncertainty of 5.7 arcseconds (radius, 90% containment). This location is 21 arcseconds from the INTEGRAL reported position, within =20 the INTEGRAL error box. The source count rate is 4.7E-03+/-1.2E-03 cts/s. At the present =20 stage, we cannot assess if the source is fading.
This circular is an official product of the Swift Team.
GCN Circular #12116
D. A. Perley, K. Clubb, M. Ganeshalingam, M. Ellison, D. Cohen, and J. S. Bloom (UC Berkeley) report:
We observed the position of INTEGRAL GRB 110708A (Gotz et al., GCN 12112) with the 1-meter Nickel telescope at Lick Observatory starting at 07:30:18 UT, 2.78 hours after the trigger. We acquired four exposures of 300 seconds each (20 minutes total integration) in the I-band filter.
The XRT position given by D'Elia et al. (GCN 12115) lies near the center of an asterism of five bright, nearby point-sources (one of which is inside the XRT error circle), all of which are also visible in USNO imaging and are likely Galactic stars. There is a possible, marginal detection of a fainter source within the XRT error circle at:
RA=22:40:27.33, dec=+53:57:42.8 (J2000)
The approximate magnitude of this object, if real, is I~20.5 (calibrated relative to USNO I-band). It is fainter than the DSS limit and also too faint to clearly detect in individual exposures, so we cannot conclusively associate it with GRB 110708A at this time.
We identify no other objects within the XRT error circle to a limiting magnitude of I > 20.3, although the limit is complicated due to crowding from the nearby stars.
GCN Circular #12117
Z. Cano (Liverpool JMU), C. Guidorzi (U. Ferrara), R.J. Smith (Liverpool JMU) report on behalf of a large collaboration:
On 2011 July 08 at 04:46:10 UT the 2-m Liverpool Telescope automatically began observing the INTEGRAL GRB 110708A (Gotz et al., GCN Circ. 12112) using the gri filters, corresponding to 168 s after the burst trigger time.
Inside the XRT error circle (D'Elia et al. GCN Circ. 12115) we do not detect any uncatalogued source. In particular, we do not detect the possible optical counterpart mentioned by Perley et al. (GCN Circ. 12116) down to the following limiting magnitudes:
```
Mid time from    Total Exp   Filter    Magnitude
trigger (min)    (s)
------------------------------------------------
20.1               30        i > 20.1
34.7              300        i > 20.4
33.0              360        r > 21.2
------------------------------------------------
```
Magnitudes have been calibrated from the nearby USNOB-1 star 1439-0418943 (RA=340.114656, Dec=+53.964514, R2=16.51 mag, I=15.85 mag).
GCN Circular #12121
T. A. Pritchard (PSU) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 110708A 34934 s after the INTEGRAL trigger (Gotz et al., GCN Circ. 12112). A faint detection of a source is detected inside of the Swift/XRT error circle (V. D'Elia et al., GCN Circ 12115) and is consistent with the position of the marginal detection by D. A. Perley et al., GCN Circ. 12116. The source appears to be of constant brightness across UVOT exposures Preliminary 3-sigma magnitudes using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the initial exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

v                34934        46819         1711         19.2 +/- 0.1
v                52022        58006         930          19.1 +/- 0.2
u                35462        53313         2220 >20.9
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.55 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #12145
J. Kelemen,(Konkoly Obs.) on behalf of the GRB OT observing program at the Konkoly Observatory.
We observed the field of INTEGRAL GRB 110708A (Gotz et al., GCN 12112) using the Swift-XRT position provided by Valerio D'Elia. (GCN 12115) with a 60/90 cm Schmidt telescope located at the Mountain Station of the Konkoly Observatory. We coadded 6 red sensitive CCD images without filter with 300 sec exposure time each. On the coadded frame we checked the position RA=22:40:27.33, dec=+53:57:42.8 (J2000) provided by Daniel Perley (GCN 12116). Very near to Perley's position, at RA=22:40:27.24, dec=+53:57:43.6 (J2000) we found a faint marginally visible source which can be identical to Perley's object. Due to the effect of the nearby dense asterism exact photometry was not possible. The brightness of this source according to our estimation (based on nearby UCAC-3 stars) is 23 +/-.5 magnitude in R the band. If Perley's and our object are identical we can suggest a fading nature for this source.
```
Time from
the trigger    magnitude       Band
----------------------------------------
154435 sec      23 +/- 0.5      R       marginal detection 
```

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Jochen Greiner, last update: 11-Jul-2011 [Disclaimer]