Gamma-ray Burst 080725

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Jul 08 10:34:00 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     317888,   Seg_Num: 0
GRB_RA:          121.715d {+08h 06m 52s} (J2000),
                 121.814d {+08h 07m 15s} (current),
                 121.133d {+08h 04m 32s} (1950)
GRB_DEC:         -13.990d {-13d 59' 23"} (J2000),
                 -14.015d {-14d 00' 53"} (current),
                 -13.845d {-13d 50' 40"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4316 [cnts]    Image_Peak=172 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   157     E_range: 50-350 keV
BKG_INTEN:       23975 [cnts]
BKG_TIME:        37557.03 SOD {10:25:57.03} UT
BKG_DUR:         8 [sec]
GRB_DATE:        14672 TJD;   207 DOY;   08/07/25
GRB_TIME:        37574.63 SOD {10:26:14.63} UT
GRB_PHI:         -134.67 [deg]
GRB_THETA:        38.01 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     21.97 [sigma]
IMAGE_SIGNIF:    7.58 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +3  +7 -100  +1 -83  +1 
SUN_POSTN:       125.14d {+08h 20m 33s}  +19.52d {+19d 31' 14"}
SUN_DIST:         33.69 [deg]   Sun_angle= 0.2 [hr] (West of Sun)
MOON_POSTN:       24.54d {+01h 38m 10s}  +15.57d {+15d 34' 08"}
MOON_DIST:       100.56 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:      234.24,  9.72 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      127.65,-33.38 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
COMMENTS:        This Notice was delayed by more than 60 sec past the end of the trigger integration interval;  
COMMENTS:        probably due to it occurring during a Malindi downlink session.  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 12.64,-2.09 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Jul 08 10:34:29 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     317888,   Seg_Num: 0
GRB_RA:          121.715d {+08h 06m 52s} (J2000),
                 121.814d {+08h 07m 15s} (current),
                 121.133d {+08h 04m 32s} (1950)
GRB_DEC:         -13.990d {-13d 59' 23"} (J2000),
                 -14.015d {-14d 00' 53"} (current),
                 -13.845d {-13d 50' 40"} (1950)
GRB_DATE:        14672 TJD;   207 DOY;   08/07/25
GRB_TIME:        37574.63 SOD {10:26:14.63} UT
TRIGGER_INDEX:   157
GRB_PHI:         -134.67 [deg]
GRB_THETA:        38.01 [deg]
DELTA_TIME:      0.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     21.97 [sigma]
IMAGE_SIGNIF:    7.58 [sigma]
LC_URL:          sw00317888000msb.lc
SUN_POSTN:       125.14d {+08h 20m 33s}  +19.52d {+19d 31' 14"}
SUN_DIST:         33.69 [deg]   Sun_angle= 0.2 [hr] (West of Sun)
MOON_POSTN:       24.55d {+01h 38m 11s}  +15.57d {+15d 34' 15"}
MOON_DIST:       100.56 [deg]
MOON_ILLUM:      54 [%]
GAL_COORDS:      234.24,  9.72 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      127.65,-33.38 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Lightcurve.  
COMMENTS:           
COMMENTS:        The next comments were copied from the BAT_POS Notice:  
COMMENTS:        This is a rate trigger.  
COMMENTS:        A point_source was found.  
COMMENTS:        This does not match any source in the on-board catalog.  
COMMENTS:        This does not match any source in the ground catalog.  
COMMENTS:        This is a GRB.  
COMMENTS:        This trigger occurred at longitude,latitude = 12.64,-2.09 [deg].

GCN Circular #8014
H. A. Krimm (CRESST/GSFC/USRA), W. H. Baumgartner (GSFC/UMBC), A. P. Beardmore (U Leicester), P. A. Evans (U Leicester), S. D. Hunsberger (PSU), S. Immler (CRESST/GSFC/UMD), J. Mao (INAF-OAB), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), D. M. Palmer (LANL), D. Perez (U Leicester), B. Preger (ASDC), R. L. C. Starling (U Leicester), G. Stratta (ASDC) and L. Vetere (PSU) report on behalf of the Swift Team:
At 10:26:14 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 080725 (trigger=317888). The BAT on-board calculated location is RA, Dec 121.715, -13.990 which is
```
   RA(J2000) = 08h 06m 52s
   Dec(J2000) = -13d 59' 23"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a double-peaked structure with a duration of about 60 sec. The peak count rate was ~2800 counts/sec (15-350 keV), at ~3 sec after the trigger.
Due to proximity to the Sun, Swift cannot slew to the BAT position. The source will not be observable until September. There will thus be no XRT or UVOT data for this trigger.
Burst Advocate for this burst is H. A. Krimm (krimm AT milkyway.gsfc.nasa.gov). 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.)
GCN Circular #8016
P. D'Avanzo, D. Fugazza, L.A. Antonelli, L. Calzoletti, S. Campana, G. Chincarini, S. Covino, M.L. Conciatore, S. Cutini, V. D'Elia, F. D'Alessio, F. Fiore, P. Goldoni, D. Guetta, C. Guidorzi, G.L. Israel, E. Maiorano, N. Masetti, A. Melandri, E. Meurs, L. Nicastro, E. Palazzi, E. Pian, S. Piranomonte, L. Stella, G. Stratta, G. Tagliaferri, G. Tosti, V.Testa, S.D. Vergani, F. Vitali report on behalf of the REM team:
The robotic 60-cm REM telescope located at La Silla (Chile) observed automatically the field of the GRB 080725 (Krimm et al. GCN 8014) on July 25 starting at 10:34:23 UT (about 8 minutes after the burst, 23 second after the trigger). Observations were carried out during twilight and at high airmass. We do not identify any obvious afterglow candidate down to R > 16.1 and H > 14.5 (3sigma c.l.) inside the BAT error box.
GCN Circular #8019
T. Ukwatta (GWU), S. D. Barthelmy (GSFC), W. Baumgartner (GSFC/UMBC), J. Cummings (GSFC/UMBC), E. Fenimore (LANL), N. Gehrels (GSFC), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), K. McLean (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), (i.e. the Swift-BAT team):
Using the data set from T-240 to T+130 sec from the recent telemetry downlink, we report further analysis of BAT GRB 080725 (trigger #317888) (Krimm, et al., GCN Circ. 8014). The BAT ground-calculated position is RA, Dec = 121.699, -13.984 deg which is
```
   RA(J2000)  =  08h 06m 47.7s
   Dec(J2000) = -13d 59' 03.4"
```
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment). The partial coding was 42%.
The mask-weighted light curve starts with a short, faint precursor from T-105 to T-100 sec. The main emission peak begins at T-20 sec and rises to a peak at T+2 sec. There is a second peak at T+13 sec, and the emission falls to background levels by T+25 sec. T90 (15-350 keV) is 120 (+5, -75) sec (estimated error including systematics). The spacecraft slewed away from the burst location starting at T+100 sec, so there is no data beyond T+130 sec.
The time-averaged spectrum from T-105.5 to T+51.8 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.50 +- 0.10. The fluence in the 15-150 keV band is 3.7 +- 0.2 x 10-6 erg/cm2. The 1-sec peak photon flux measured from T+3.54 sec in the 15-150 keV band is 2.3 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/317888/BA/

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Jochen Greiner, last update: 25-Jul-2008 [Disclaimer]