Gamma-ray Burst 060825

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:00:16 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     226382,   Seg_Num: 0
GRB_RA:           18.102d {+01h 12m 24s} (J2000),
                  18.204d {+01h 12m 49s} (current),
                  17.337d {+01h 09m 21s} (1950)
GRB_DEC:         +55.805d {+55d 48' 18"} (J2000),
                 +55.840d {+55d 50' 25"} (current),
                 +55.540d {+55d 32' 24"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       8422 [cnts]    Image_Peak=950 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       35502 [cnts]
BKG_TIME:        10782.59 SOD {02:59:42.59} UT
BKG_DUR:         8 [sec]
GRB_DATE:        13972 TJD;   237 DOY;   06/08/25
GRB_TIME:        10797.70 SOD {02:59:57.70} UT
GRB_PHI:         106.79 [deg]
GRB_THETA:        12.17 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     54.01 [sigma]
IMAGE_SIGNIF:    20.09 [sigma]
MERIT_PARAMS:     +1  +0  +0  +1  +2 +17  +0  +1 +24  +1 
SUN_POSTN:       153.80d {+10h 15m 11s}  +10.84d {+10d 50' 14"}
SUN_DIST:        103.79 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.68d {+11h 10m 43s}   +6.14d {+06d 08' 09"}
MOON_DIST:       113.11 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.90, -6.95 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       42.48, 43.58 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT-BAT GRB Coordinates.  
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 = 81.80,15.15 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:01:19 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     226382,   Seg_Num: 0
POINT_RA:         18.121d {+01h 12m 29s} (J2000)
POINT_DEC:       +55.809d {+55d 48' 33"} (J2000)
IMG_START_DATE:  13972 TJD;   237 DOY;   06/08/25
IMG_START_TIME:  10863.30 SOD {03:01:03.30} UT,   65.6 [sec] since BAT Trigger Time
COUNTS:          7    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:03:30 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     226382,   Seg_Num: 0
GRB_RA:           18.102d {+01h 12m 24s} (J2000),
                  18.204d {+01h 12m 49s} (current),
                  17.337d {+01h 09m 21s} (1950)
GRB_DEC:         +55.805d {+55d 48' 18"} (J2000),
                 +55.840d {+55d 50' 25"} (current),
                 +55.540d {+55d 32' 24"} (1950)
GRB_DATE:        13972 TJD;   237 DOY;   06/08/25
GRB_TIME:        10797.70 SOD {02:59:57.70} UT
TRIGGER_INDEX:   146
GRB_PHI:         106.79 [deg]
GRB_THETA:        12.17 [deg]
DELTA_TIME:      -70.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     54.01 [sigma]
IMAGE_SIGNIF:    20.09 [sigma]
LC_URL:          sw00226382000msb.lc
SUN_POSTN:       153.80d {+10h 15m 11s}  +10.84d {+10d 50' 11"}
SUN_DIST:        103.79 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.70d {+11h 10m 49s}   +6.12d {+06d 07' 24"}
MOON_DIST:       113.13 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.90, -6.95 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       42.48, 43.58 [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 = 81.80,15.15 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:04:49 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     226382,   Seg_Num: 0
POINT_RA:         18.123d {+01h 12m 29s} (J2000)
POINT_DEC:       +55.810d {+55d 48' 35"} (J2000)
POINT_ROLL:      44.955d
IMG_START_DATE:  13972 TJD;   237 DOY;   06/08/25
IMG_START_TIME:  10869.48 SOD {03:01:09.48} UT,   71.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.047
N_STARS:         111
X_OFFSET:        373 [pixels]
Y_OFFSET:        565 [pixels]
X_MAX:           1332 [pixels]
Y_MAX:           1524 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00226382000msufc0071.fits
SUN_POSTN:       153.80d {+10h 15m 12s}  +10.84d {+10d 50' 10"}
SUN_DIST:        103.78 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.71d {+11h 10m 51s}   +6.12d {+06d 07' 05"}
MOON_DIST:       113.13 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.91, -6.94 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       42.50, 43.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:05:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     226382,   Seg_Num: 0
POINT_RA:         18.123d {+01h 12m 29s} (J2000)
POINT_DEC:       +55.810d {+55d 48' 35"} (J2000)
POINT_ROLL:      44.955d
IMG_START_DATE:  13972 TJD;   237 DOY;   06/08/25
IMG_START_TIME:  10869.48 SOD {03:01:09.48} UT,   71.8 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.047
N_STARS:         111
X_OFFSET:        373 [pixels]
Y_OFFSET:        565 [pixels]
X_MAX:           1332 [pixels]
Y_MAX:           1524 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00226382000msufc0071.fits
SUN_POSTN:       153.80d {+10h 15m 12s}  +10.84d {+10d 50' 09"}
SUN_DIST:        103.78 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.72d {+11h 10m 52s}   +6.12d {+06d 06' 59"}
MOON_DIST:       113.13 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.91, -6.94 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       42.50, 43.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:06:49 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     226382,   Seg_Num: 0
POINT_RA:         18.123d {+01h 12m 29s} (J2000)
POINT_DEC:       +55.810d {+55d 48' 35"} (J2000)
ROLL:            44.955d
IMG_START_DATE:  13972 TJD;   237 DOY;   06/08/25
IMG_START_TIME:  10869.48 SOD {03:01:09.48} UT,   71.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     178167670
X_OFFSET:        692 [pixels]
Y_OFFSET:        884 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       852
Y_GRB_POS:       1044
BINNING_INDEX:   1
IM_URL:          sw00226382000msuni0071.fits
SUN_POSTN:       153.80d {+10h 15m 12s}  +10.84d {+10d 50' 08"}
SUN_DIST:        103.78 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.73d {+11h 10m 55s}   +6.11d {+06d 06' 37"}
MOON_DIST:       113.14 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.91, -6.94 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       42.50, 43.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:07:02 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     226382,   Seg_Num: 0
POINT_RA:         18.123d {+01h 12m 29s} (J2000)
POINT_DEC:       +55.810d {+55d 48' 35"} (J2000)
ROLL:            44.955d
IMG_START_DATE:  13972 TJD;   237 DOY;   06/08/25
IMG_START_TIME:  10869.48 SOD {03:01:09.48} UT,   71.8 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     178167670
X_OFFSET:        692 [pixels]
Y_OFFSET:        884 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       852
Y_GRB_POS:       1044
BINNING_INDEX:   1
IM_URL:          sw00226382000msuni0071.fits
SUN_POSTN:       153.80d {+10h 15m 12s}  +10.84d {+10d 50' 08"}
SUN_DIST:        103.78 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.73d {+11h 10m 55s}   +6.11d {+06d 06' 34"}
MOON_DIST:       113.14 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.91, -6.94 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       42.50, 43.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:07:24 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     226382,   Seg_Num: 0
POINT_RA:         18.125d {+01h 12m 30s} (J2000)
POINT_DEC:       +55.810d {+55d 48' 37"} (J2000)
POINT_ROLL:      44.956d
IMG_START_DATE:  13972 TJD;   237 DOY;   06/08/25
IMG_START_TIME:  10975.17 SOD {03:02:55.17} UT,   177.5 [sec] since BAT Trigger Time
FILTER:          4, UVM2
BKG_MEAN:        0.067
N_STARS:         15
X_OFFSET:        373 [pixels]
Y_OFFSET:        565 [pixels]
X_MAX:           1332 [pixels]
Y_MAX:           1524 [pixels]
DET_THRESH:      3
PHOTO_THRESH:    2
SL_URL:          sw00226382000msufc0177.fits
SUN_POSTN:       153.80d {+10h 15m 12s}  +10.84d {+10d 50' 07"}
SUN_DIST:        103.78 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.73d {+11h 10m 56s}   +6.11d {+06d 06' 29"}
MOON_DIST:       113.14 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.91, -6.94 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       42.50, 43.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:07:52 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     226382,   Seg_Num: 0
POINT_RA:         18.125d {+01h 12m 30s} (J2000)
POINT_DEC:       +55.810d {+55d 48' 37"} (J2000)
POINT_ROLL:      44.956d
IMG_START_DATE:  13972 TJD;   237 DOY;   06/08/25
IMG_START_TIME:  10975.17 SOD {03:02:55.17} UT,   177.5 [sec] since BAT Trigger Time
FILTER:          4, UVM2
BKG_MEAN:        0.067
N_STARS:         15
X_OFFSET:        373 [pixels]
Y_OFFSET:        565 [pixels]
X_MAX:           1332 [pixels]
Y_MAX:           1524 [pixels]
DET_THRESH:      3
PHOTO_THRESH:    2
SL_URL:          sw00226382000msufc0177.fits
SUN_POSTN:       153.80d {+10h 15m 12s}  +10.84d {+10d 50' 07"}
SUN_DIST:        103.78 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.74d {+11h 10m 57s}   +6.11d {+06d 06' 23"}
MOON_DIST:       113.14 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.91, -6.94 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       42.50, 43.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_srclist.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:08:49 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     226382,   Seg_Num: 0
POINT_RA:         18.125d {+01h 12m 30s} (J2000)
POINT_DEC:       +55.810d {+55d 48' 37"} (J2000)
ROLL:            44.956d
IMG_START_DATE:  13972 TJD;   237 DOY;   06/08/25
IMG_START_TIME:  10975.17 SOD {03:02:55.17} UT,   177.5 [sec] since BAT Trigger Time
FILTER:          4, UVM2
EXPOSURE_ID:     178167776
X_OFFSET:        692 [pixels]
Y_OFFSET:        884 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       852
Y_GRB_POS:       1044
BINNING_INDEX:   1
IM_URL:          sw00226382000msuni0177.fits
SUN_POSTN:       153.80d {+10h 15m 12s}  +10.84d {+10d 50' 06"}
SUN_DIST:        103.78 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.74d {+11h 10m 59s}   +6.10d {+06d 06' 09"}
MOON_DIST:       113.15 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.91, -6.94 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       42.50, 43.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:09:07 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     226382,   Seg_Num: 0
POINT_RA:         18.125d {+01h 12m 30s} (J2000)
POINT_DEC:       +55.810d {+55d 48' 37"} (J2000)
ROLL:            44.956d
IMG_START_DATE:  13972 TJD;   237 DOY;   06/08/25
IMG_START_TIME:  10975.17 SOD {03:02:55.17} UT,   177.5 [sec] since BAT Trigger Time
FILTER:          4, UVM2
EXPOSURE_ID:     178167776
X_OFFSET:        692 [pixels]
Y_OFFSET:        884 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       852
Y_GRB_POS:       1044
BINNING_INDEX:   1
IM_URL:          sw00226382000msuni0177.fits
SUN_POSTN:       153.80d {+10h 15m 12s}  +10.83d {+10d 50' 06"}
SUN_DIST:        103.78 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.75d {+11h 10m 59s}   +6.10d {+06d 06' 05"}
MOON_DIST:       113.15 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.91, -6.94 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       42.50, 43.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        If you have elected to receive attachments:  
COMMENTS:        The uvot_catalog_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 25 Aug 06 03:25:46 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     226382,   Seg_Num: 0
GRB_RA:           18.1209d {+01h 12m 29.0s} (J2000),
                  18.2230d {+01h 12m 53.5s} (current),
                  17.3562d {+01h 09m 25.4s} (1950)
GRB_DEC:         +55.7961d {+55d 47' 45.9"} (J2000),
                 +55.8313d {+55d 49' 52.5"} (current),
                 +55.5309d {+55d 31' 51.3"} (1950)
GRB_ERROR:       5.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      5.00 [sigma]
IMG_START_DATE:  13972 TJD;   237 DOY;   06/08/25
IMG_START_TIME:  10863.29 SOD {03:01:03.29} UT,   65.6 [sec] since BAT Trigger Time
TAM[0-3]:        327.61 237.19 261.35 242.66
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       153.81d {+10h 15m 15s}  +10.83d {+10d 49' 52"}
SUN_DIST:        103.80 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      167.87d {+11h 11m 28s}   +6.04d {+06d 02' 12"}
MOON_DIST:       113.26 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:      125.91, -6.95 [deg] galactic lon,lat of the burst
ECL_COORDS:       42.49, 43.57 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values are not valid.

GCN Circular #5471
G. Sato (GSFC/ISAS), S. D. Barthelmy (GSFC), M. M. Chester (PSU), N. Gehrels (NASA/GSFC), S. T. Holland (GSFC/USRA), S. Immler (GSFC/USRA), J. A. Kennea (PSU), H. A. Krimm (GSFC/USRA), F. E. Marshall (NASA/GSFC), K. M. McLean (LANL/UTD), K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of the Swift Team:
At 02:59:57 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 060825 (trigger=226382). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 18.102, +55.805 {01h 12m 24s, +55d 48' 18"} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single bright peak with some structure and a duration of about 15 sec. The peak count rate was ~4000 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began taking data at 03:01:03 UT, 66 seconds after the BAT trigger. The XRT on-board centroid algorithm did not find a source in the image, however ground analysis of quicklook data reveals a faint uncatalogued point source at the following coordinates: RA(J2000) = 01h 12m 28.9s, Dec(J2000) = +55d 47m 46.4s with an error of 5.4 arcseconds radius (90% confidence). This position is 49 arcseconds from the BAT position.
UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 72 seconds after the BAT trigger. No afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 18.5 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.57.
GCN Circular #5472
A. de Ugarte Postigo, J.Gorosabel, M. Jelinek, R. Cunniffe, S. Vitek, A.J. Castro-Tirado (IAA-CSIC Granada),P. Kubanek (ASU AV CR Ondrejov & ISDC Versoix) and L.D. Sabau-Graziati (INTA Torrejon de Ardoz, Madrid) report
Main text: "The BOOTES-IR 0.6m telescope, located at IAA-CSIC Observatorio de Sierra Nevada in Granada (Spain), observed the SWIFT error box for GRB 060825 (Sato et al. GCNC 5471) starting at 03:26 UT in R-band.
We detect an object on the edge of the XRT error box at coordinates R.A.= 01:12:29.58, Dec. = +55:47:43.8 (J2000) with estimated uncertanity of 0.7 arcsec which might be present at the DSS2 image.
A finding chart will be soon available at: www.iaa.es/~deugarte/GRBs/060825/grb060825.gif
This message is quotable".
GCN Circular #5473
S. B. Cenko (Caltech) and D. B. Fox (Penn State) report on behalf of a larger collaboration:
We have imaged the field of GRB 060825 (Sato et al., GCN 5471) with the automated Palomar 60-inch telescope. Images consisted of 6 x 180 s exposures in the Kron R and Sloan i' filters taken at a mean epoch of approximately August 25.2 UT (~ 2 hr after the burst).
We clearly detect the object identified by de Ugarte Postigo et al. (GCN 5472) in both filters. The object has a magnitude R ~ 21.2, I ~ 19.5 in our images (measured with respect to the USNO-B catalog). However, as noted already, the object appears to be present in the DSS2 red plates.
We find no other objects inside the XRT error circle, to a limiting magnitude of approximately R > 22.0, I > 21.0. No values in this circular have been corrected for the large Galactic extinction along the line of sight.
GCN Circular #5474
Klotz, A. (CESR-OMP), Boer M. (OHP), Atteia J.L. (LATT-OMP) report:
We imaged the field of GRB 060825 detected by SWIFT (trigger 226382) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France.
First image was acquired 25.7s after the GRB trigger (7.1s after the notice). The field elevation decreased from 77 degrees above horizon and weather conditions were good.
Date of trigger : t0 = 2006-08-25T02:59:57.408
First image is 60.0 exposure trailed. No OT is visible: t0+25.7s to t0+85.7s : R > 14.9
Second image is 30.0 exposure. No OT is visible: t0+93.5s to t0+123.5s : R > 15.8
We co-added a series of exposures. No OT is visible: t0+93.5s to t0+377.7s : R > 18.4
We do not detect the candidate of de Ugarte Postigo et al. (GCNC 5472).
Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon=125.8970 lat= -6.9459 and the galactic extinction in R band is 0.7 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S.
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GCN Circular #5475
P. D'Avanzo, S. Covino (INAF-OABrera), L. A. Antonelli (INAF-OAR) on behalf of a larger collaboration and A. Magazzu` (INAF-TNG), report:
We observed the field of GRB 060825 (Sato et al., GCN 5471) with the italian 3.6m TNG telescope, sited in Canary Island, Spain. A set of BVRI images have been collected, with a seeing of 1.3". The mean epoch of observations is Aug 25.22 UT. We clearly see the DSS object reported by de Ugarte Postigo et al. (GCN 5472) and Cenko et al. (GCN 5473).
No new object is seen inside the XRT error box , to a limiting magnitude of R > 23.9 (3sigma level).
We thank TNG staff for their support.
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GCN Circular #5476
A. Gomboc reports on behalf of the Liverpool GRB group:
The 2-m Liverpool Telescope (La Palma, Canary Islands) robotically followed-up GRB060825 (SWIFT trigger 226382, Sato et al. GCN 5471) starting 2.6 min after the GRB trigger time. We do not find an optical counterpart in 6 x 10s co-added images at the mean time 5.7 min after the trigger to a limiting magnitude of R~18.3.
Limiting magnitude has been derived with reference to USNOB1.
GCN Circular #5478
E. Fenimore (LANL), L. Barbier (GSFC), S. Barthelmy (GSFC), J. Cummings (GSFC/ORAU), N. Gehrels (GSFC), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), on behalf of the Swift-BAT team:
Using the data set from T-240 to T+614 sec from the recent telemetry downlink, we report further analysis of Swift GRB 060825 (trigger #226382) (Sato, et al., GCN Circ. 5471). The BAT ground-calculated position is (RA,Dec) = 18.130, 55.796 deg {1h 12m 31.3s, 55d 47' 44.7"} (J2000) +- 0.7 arcmin, (radius, sys+stat, 90% containment). The partial coding was 90%.
The mask-weighted light curve shows a single broad peak from T-4 sec to T+7 sec T90 (15-350 keV) is 8.1 +- 1 sec (estimated error including systematics).
The time-averaged spectrum from T-4.2 to T+7.0 is best fit by a power law with an exponential cutoff. This fit gives a photon index 1.11 +- 0.32, and Epeak of 73 +- 18 keV (chi squared 54.91 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 9.8 +- 0.5 x 10^-7 erg/cm2 and the 1-sec peak flux measured from T+0.07 sec in the 15-150 keV band is 2.7 +- 0.2 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.71 +- 0.07 (chi squared 67.23 for 57 d.o.f.). All the quoted errors are at the 90% confidence level.
GCN Circular #5479
A.P. Beardmore, K.L. Page (U. Leicester) & G. Sato (GSFC/ISAS) report on behalf of the Swift-XRT team:
We have analysed the first 4 orbits of Swift-XRT data obtained for GRB 060825 (trigger 226382). From 3660 seconds of data, we find a refined position of:
```
RA(J2000)  =   01 12 29.00
Dec(J2000) =  +55 47 46.5
```
with an uncertainty of 4.1 arcsec (90% containment). This is 0.8 arcsec from the XRT position reported in GCN Circ. 5471 (Sato et al.), and 18.6 arcsec from the refined BAT position in GCN Circ. 5478 (Fenimore et al.).
The X-ray afterglow is faint, initially only 0.8 count/s, 74s after the BAT trigger, decaying with a slope of alpha = 0.87 +/- 0.09 out to 20ks. There is, however, a small flare centred at 220s, where the count rate rises to 1.2 count/s.
The X-ray spectrum from the first four orbits can be well fitted by an absorbed power-law, with a photon index of Gamma = 1.64 +/- 0.29 absorbed by the Galactic column density of 3.0e21 cm^-2. The early time unabsorbed flux (between 74 - 189s after the trigger) was 3.57e-11 erg cm^-2 s^-1 over the 0.3-10 keV band.
Providing the source decays at the same rate then the count rate is predicted to be ~0.002 count/s 24 hr after the trigger, which corresponds to an observed 0.3-10keV flux of 1.20e-13 erg cm^-2 s^-1, or an unabsorbed flux of 1.58e-13 erg cm^-2 s^-1.
This circular is an offical product of the Swift-XRT team.
GCN Circular #5483
A. Pelangeon & J-L. Atteia (LATT-OMP) report:
We have used the spectral parameters of GRB 060825 provided by Fenimore et al. (GCNC 5478) to compute the spectral pseudo-redshift** of this burst detected by SWIFT-BAT (Sato et al., GCNC 5471).
We find a pseudo-redshift pz= 2.0 +/- 0.6
** cf. http://www.ast.obs-mip.fr/grb/pz
GCN Circular #5484
P. Chandra (UVA/NRAO) and D. A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration:
"We observed the field centered on the BAT position of the Swift burst GRB 060825 (GCN#5472) using the VLA at a frequency of 8.46 GHz at 2 epochs. There is no detection of the GRB at both the epochs.
```
Date        UT    rms(microJy)    2-sigma upper limit
2006-08-27    9.36    45        < 90 microJy
2006-08-29    8.23    47        < 94 microJy
```
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN Circular #5571
Gaug M. and Garczarczyk M., Bastieri D., Fagiolini M., Galante N., Longo F., Mizobuchi S., Picciolini A., Scampin V. and Stamerra A. report for the MAGIC collaboration:
The MAGIC Imaging Atmospheric Cherenkov Telescope performed a follow-up observation of the SWIFT-BAT burst GRB060825 (GCN circular 5478, Fenimore E. et al.). We received the GCN alert at T0+19s. The telescope slewed fast to the GRB sky coordinates and started data taking 38s after the alert, at T0+57s. In total 33min of data from the GRB sky coordinates were accumulated. Due to the short duration of the burst (T90 = 8.8s), only the early afterglow phase was observed. The observation overlapped with the small x-ray flare detected by SWIFT-XRT (GCN circular 5479, Beardmore A.P. et al.), centered at T0+220s.
No evidence for VHE emission above the analysis threshold of 90GeV was found. A preliminary analysis, for the hypothesis of steady emission and assumption of a differential photon spectral index of -2.5, yields the following 95% CL differential flux upper limits (inc. 30% systematic error on the absolute flux level):
```
E(80-125 GeV)   : 1.8 x 10^(-10) erg/cm^2/s
E(125-175 GeV)  : 1.9 x 10^(-10) erg/cm^2/s
E(175-300 GeV)  : 1.2 x 10^(-10) erg/cm^2/s
E(300-1000 GeV) : 0.6 x 10^(-10) erg/cm^2/s
```
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GCN Circular #5727
J. Haislip, G. Spear, T. Graves, M. Nysewander, D. Reichart, K. Ivarsen, A. Foster, A. LaCluyze, J. A. Crain report:
Skynet observed the localization of GRB 060825 (Sato et al., GCN 5471) with the GLAST Optical Robotic Telescope (GORT) in California beginning 1.1 hours after the burst in BVRI.
No new source is detected within the XRT error circle to a 3-sigma limiting magnitude of R > 21.0 at a mean time of 5.4 hours after the burst.

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Jochen Greiner, last update: 13-Oct-2006 [Disclaimer]