Gamma-ray Burst 060804

(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 04 Aug 06 07:29:11 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     222546,   Seg_Num: 0
GRB_RA:          112.201d {+07h 28m 48s} (J2000),
                 112.268d {+07h 29m 04s} (current),
                 111.693d {+07h 26m 46s} (1950)
GRB_DEC:         -27.231d {-27d 13' 52"} (J2000),
                 -27.245d {-27d 14' 42"} (current),
                 -27.127d {-27d 07' 37"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       32949 [cnts]    Image_Peak=395 [image_cnts]
TRIGGER_DUR:     8.192 [sec] 
TRIGGER_INDEX:   336     E_range: 25-100 keV
BKG_INTEN:       242925 [cnts]
BKG_TIME:        26806.64 SOD {07:26:46.64} UT
BKG_DUR:         64 [sec]
GRB_DATE:        13951 TJD;   216 DOY;   06/08/04
GRB_TIME:        26899.82 SOD {07:28:19.82} UT
GRB_PHI:         -95.79 [deg]
GRB_THETA:        36.85 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     10.81 [sigma]
IMAGE_SIGNIF:    8.92 [sigma]
MERIT_PARAMS:     +1  +0  +0  +3  +2  +0  +0  +1 -65  +1 
SUN_POSTN:       134.26d {+08h 57m 02s}  +17.25d {+17d 14' 58"}
SUN_DIST:         49.34 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.34d {+16h 05m 20s}  -25.74d {-25d 44' 29"}
MOON_DIST:       107.81 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.26, -4.60 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      120.37,-48.36 [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 = 90.42,-13.85 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 04 Aug 06 07:30:30 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     222546,   Seg_Num: 0
POINT_RA:        112.210d {+07h 28m 50s} (J2000)
POINT_DEC:       -27.245d {-27d 14' 41"} (J2000)
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27021.26 SOD {07:30:21.26} UT,   121.4 [sec] since BAT Trigger Time
COUNTS:          4    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 04 Aug 06 07:33:09 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     222546,   Seg_Num: 0
GRB_RA:          112.201d {+07h 28m 48s} (J2000),
                 112.268d {+07h 29m 04s} (current),
                 111.693d {+07h 26m 46s} (1950)
GRB_DEC:         -27.231d {-27d 13' 52"} (J2000),
                 -27.245d {-27d 14' 42"} (current),
                 -27.127d {-27d 07' 37"} (1950)
GRB_DATE:        13951 TJD;   216 DOY;   06/08/04
GRB_TIME:        26899.82 SOD {07:28:19.82} UT
TRIGGER_INDEX:   336
GRB_PHI:         -95.79 [deg]
GRB_THETA:        36.85 [deg]
DELTA_TIME:      -38.00 [sec]
TRIGGER_DUR:     8.192 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     10.81 [sigma]
IMAGE_SIGNIF:    8.92 [sigma]
LC_URL:          sw00222546000msb.lc
SUN_POSTN:       134.26d {+08h 57m 03s}  +17.25d {+17d 14' 56"}
SUN_DIST:         49.34 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.37d {+16h 05m 30s}  -25.75d {-25d 44' 58"}
MOON_DIST:       107.83 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.26, -4.60 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      120.37,-48.36 [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 = 90.42,-13.85 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 04 Aug 06 07:33:52 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     222546,   Seg_Num: 0
POINT_RA:        112.210d {+07h 28m 50s} (J2000)
POINT_DEC:       -27.245d {-27d 14' 41"} (J2000)
POINT_ROLL:      28.212d
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27025.76 SOD {07:30:25.76} UT,   125.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.998
N_STARS:         190
X_OFFSET:        500 [pixels]
Y_OFFSET:        432 [pixels]
X_MAX:           1459 [pixels]
Y_MAX:           1391 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    9
SL_URL:          sw00222546000msufc0125.fits
SUN_POSTN:       134.26d {+08h 57m 03s}  +17.25d {+17d 14' 55"}
SUN_DIST:         49.35 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.38d {+16h 05m 31s}  -25.75d {-25d 45' 03"}
MOON_DIST:       107.82 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.28, -4.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.39,-48.37 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 04 Aug 06 07:36:01 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     222546,   Seg_Num: 0
POINT_RA:        112.210d {+07h 28m 50s} (J2000)
POINT_DEC:       -27.245d {-27d 14' 41"} (J2000)
POINT_ROLL:      28.212d
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27025.76 SOD {07:30:25.76} UT,   125.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.998
N_STARS:         190
X_OFFSET:        500 [pixels]
Y_OFFSET:        432 [pixels]
X_MAX:           1459 [pixels]
Y_MAX:           1391 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    9
SL_URL:          sw00222546000msufc0125.fits
SUN_POSTN:       134.26d {+08h 57m 03s}  +17.25d {+17d 14' 54"}
SUN_DIST:         49.35 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.40d {+16h 05m 36s}  -25.76d {-25d 45' 18"}
MOON_DIST:       107.83 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.28, -4.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.39,-48.37 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 04 Aug 06 07:36:11 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     222546,   Seg_Num: 0
POINT_RA:        112.210d {+07h 28m 50s} (J2000)
POINT_DEC:       -27.245d {-27d 14' 41"} (J2000)
ROLL:            28.212d
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27025.76 SOD {07:30:25.76} UT,   125.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     176369427
X_OFFSET:        819 [pixels]
Y_OFFSET:        751 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       979
Y_GRB_POS:       911
BINNING_INDEX:   1
IM_URL:          sw00222546000msuni0125.fits
SUN_POSTN:       134.26d {+08h 57m 03s}  +17.25d {+17d 14' 54"}
SUN_DIST:         49.35 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.40d {+16h 05m 37s}  -25.76d {-25d 45' 19"}
MOON_DIST:       107.83 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.28, -4.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.39,-48.37 [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 04 Aug 06 07:37:39 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     222546,   Seg_Num: 0
POINT_RA:        112.210d {+07h 28m 50s} (J2000)
POINT_DEC:       -27.245d {-27d 14' 41"} (J2000)
ROLL:            28.212d
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27025.76 SOD {07:30:25.76} UT,   125.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     176369427
X_OFFSET:        819 [pixels]
Y_OFFSET:        751 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       979
Y_GRB_POS:       911
BINNING_INDEX:   1
IM_URL:          sw00222546000msuni0125.fits
SUN_POSTN:       134.26d {+08h 57m 03s}  +17.25d {+17d 14' 53"}
SUN_DIST:         49.35 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.42d {+16h 05m 40s}  -25.76d {-25d 45' 30"}
MOON_DIST:       107.84 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.28, -4.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.39,-48.37 [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:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 04 Aug 06 07:48:08 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     222546,   Seg_Num: 0
POINT_RA:        112.208d {+07h 28m 50s} (J2000)
POINT_DEC:       -27.247d {-27d 14' 50"} (J2000)
POINT_ROLL:      28.212d
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27131.04 SOD {07:32:11.04} UT,   231.2 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        4.341
N_STARS:         190
X_OFFSET:        500 [pixels]
Y_OFFSET:        432 [pixels]
X_MAX:           1459 [pixels]
Y_MAX:           1391 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    10
SL_URL:          sw00222546000msufc0231.fits
SUN_POSTN:       134.27d {+08h 57m 05s}  +17.25d {+17d 14' 46"}
SUN_DIST:         49.36 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.52d {+16h 06m 05s}  -25.78d {-25d 46' 45"}
MOON_DIST:       107.89 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.28, -4.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.39,-48.37 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 04 Aug 06 07:49:10 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     222546,   Seg_Num: 0
POINT_RA:        112.208d {+07h 28m 50s} (J2000)
POINT_DEC:       -27.247d {-27d 14' 50"} (J2000)
ROLL:            28.212d
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27131.04 SOD {07:32:11.04} UT,   231.2 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     176369532
X_OFFSET:        819 [pixels]
Y_OFFSET:        751 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       979
Y_GRB_POS:       911
BINNING_INDEX:   1
IM_URL:          sw00222546000msuni0231.fits
SUN_POSTN:       134.27d {+08h 57m 05s}  +17.25d {+17d 14' 45"}
SUN_DIST:         49.36 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.53d {+16h 06m 07s}  -25.78d {-25d 46' 53"}
MOON_DIST:       107.89 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.28, -4.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.39,-48.37 [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 04 Aug 06 07:50:08 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     222546,   Seg_Num: 0
POINT_RA:        112.208d {+07h 28m 50s} (J2000)
POINT_DEC:       -27.247d {-27d 14' 50"} (J2000)
POINT_ROLL:      28.212d
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27131.04 SOD {07:32:11.04} UT,   231.2 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        4.341
N_STARS:         190
X_OFFSET:        500 [pixels]
Y_OFFSET:        432 [pixels]
X_MAX:           1459 [pixels]
Y_MAX:           1391 [pixels]
DET_THRESH:      17
PHOTO_THRESH:    10
SL_URL:          sw00222546000msufc0231.fits
SUN_POSTN:       134.27d {+08h 57m 05s}  +17.25d {+17d 14' 45"}
SUN_DIST:         49.36 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.54d {+16h 06m 09s}  -25.78d {-25d 47' 00"}
MOON_DIST:       107.90 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.28, -4.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.39,-48.37 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Source List.  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 04 Aug 06 07:50:22 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     222546,   Seg_Num: 0
POINT_RA:        112.208d {+07h 28m 50s} (J2000)
POINT_DEC:       -27.247d {-27d 14' 50"} (J2000)
ROLL:            28.212d
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27131.04 SOD {07:32:11.04} UT,   231.2 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     176369532
X_OFFSET:        819 [pixels]
Y_OFFSET:        751 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       979
Y_GRB_POS:       911
BINNING_INDEX:   1
IM_URL:          sw00222546000msuni0231.fits
SUN_POSTN:       134.27d {+08h 57m 05s}  +17.25d {+17d 14' 44"}
SUN_DIST:         49.36 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.54d {+16h 06m 10s}  -25.78d {-25d 47' 01"}
MOON_DIST:       107.90 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.28, -4.60 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      120.39,-48.37 [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:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 04 Aug 06 07:55:53 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     222546,   Seg_Num: 0
GRB_RA:          112.2079d {+07h 28m 49.8s} (J2000),
                 112.2749d {+07h 29m 05.9s} (current),
                 111.6999d {+07h 26m 47.9s} (1950)
GRB_DEC:         -27.2160d {-27d 12' 57.6"} (J2000),
                 -27.2299d {-27d 13' 47.5"} (current),
                 -27.1119d {-27d 06' 42.8"} (1950)
GRB_ERROR:       3.6 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      15.00 [sigma]
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27031.50 SOD {07:30:31.50} UT,   131.7 [sec] since BAT Trigger Time
TAM[0-3]:        327.61 237.19 261.35 242.66
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       134.28d {+08h 57m 06s}  +17.24d {+17d 14' 41"}
SUN_DIST:         49.33 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.59d {+16h 06m 23s}  -25.79d {-25d 47' 41"}
MOON_DIST:       107.95 [deg]
MOON_ILLUM:      69 [%]
GAL_COORDS:      241.25, -4.59 [deg] galactic lon,lat of the burst
ECL_COORDS:      120.38,-48.34 [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 #5394
H. Z. Ziaeepour (UCL-MSSL), S. D. Barthelmy (GSFC), D. N. Burrows (PSU), J. R. Cummings (NASA/UMD), N. Gehrels (NASA/GSFC), C. Guidorzi (Univ Bicocca&INAF-OAB), J. A. Kennea (PSU), C. B. Markwardt (GSFC/UMD), M. J. Page (UCL-MSSL), K. L. Page (U Leicester), D. M. Palmer (LANL), G. Sato (GSFC/ISAS), M. Stamatikos (NASA/ORAU) and G. Tagliaferri (INAF-OAB) report on behalf of the Swift Team:
At 07:28:19 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 060804 (trigger=222546). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 112.201, -27.231 {07h 28m 48s, -27d 13' 52"} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 10 sec. The peak count rate was ~600 counts/sec (15-350 keV), at ~5 sec after the trigger.
The XRT began taking data at 07:30:21 UT, 121 seconds after the BAT trigger. Although the XRT on-board centroid algorithm did not find a source in the image, ground analysis revealed an uncatalogued point source at a position of RA(J2000) = 07h 28m 49.40s, Dec(J2000) = -27d 12' 58.9", with an estimated error of 3.9 arcsec radius (90% containment).
UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 128 seconds after the BAT trigger. A possible afterglow candidate is seen in the 2.7'x2.7' sub-image with an estimated magnitude of V=17 at position RA(J2000) = 07h 28m 49.36s Dec(J2000) = -27d 12' 56.7" with an estimated error of 1".
The Be star SPH 10 is in the BAT error circle. However, it is inconsistent with the XRT and UVOT source location (2 arcminutes) and is therefore unlikely to be associated with the burst.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 04 Aug 06 08:12:12 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     222546,   Seg_Num: 0
GRB_RA:          112.2056d {+07h 28m 49.34s} (J2000),
                 112.2726d {+07h 29m 05.41s} (current),
                 111.6976d {+07h 26m 47.41s} (1950)
GRB_DEC:         -27.2156d {-27d 12' 56.1"} (J2000),
                 -27.2295d {-27d 13' 46.1"} (current),
                 -27.1115d {-27d 06' 41.4"} (1950)
GRB_ERROR:       0.7 [arcsec radius, statistical only]
GRB_MAG:         18.00 +/- 1.00 [mag]
FILTER:          3, V
IMG_START_DATE:  13951 TJD;   216 DOY;   06/08/04
IMG_START_TIME:  27131.04 SOD {07:32:11.04} UT,   231.2 [sec] since BAT Trigger Time
SUN_POSTN:       134.29d {+08h 57m 09s}  +17.24d {+17d 14' 30"}
SUN_DIST:         49.33 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      241.75d {+16h 07m 01s}  -25.83d {-25d 49' 37"}
MOON_DIST:       108.03 [deg]
MOON_ILLUM:      70 [%]
GAL_COORDS:      241.25, -4.59 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      120.37,-48.34 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        UVOT magnitude is a rough estimate

GCN Circular #5395
J. Tueller (GSFC), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/ORAU), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), M. Koss (GSFC/UMD), C. Markwardt (GSFC/UMD), D. Palmer (LANL), A. Parsons (GSFC), T. Sakamoto (GSFC/ORAU), G. Sato (GSFC/ISAS), M. Stamatikos (GSFC/ORAU), H. Z. Ziaeepour (UCL-MSSL) on behalf of the Swift-BAT team:
Using the data set from T-240 to T+800 sec from recent telemetry downlinks, we report further analysis of BAT GRB 060804 (trigger #222546) (Ziaeepour, et al., GCN Circ. 5394). The BAT ground-calculated position is RA,Dec = 112.216, -27.228 deg {7h 28m 51.8s, -27d 13' 41.8"} (J2000) +- 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 18%.
The mask-weighted lightcurve shows two overlapping peaks. The first starts at T-14 sec and peaking at T-10 sec. The second peaks at T+4 sec. T90 (15-350 keV) is 16 +- 2 sec (estimated error including systematics).
The time-averaged spectrum from T-12.3 to T+5.5 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.78 +- 0.28. The fluence in the 15-150 keV band is 5.1 +- 0.9 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+4.46 sec in the 15-150 keV band is 1.2 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
GCN Circular #5396
K.L. Page (U. Leicester) & H.Z. Ziaeepour (UCL-MSSL) report on behalf of the Swift-XRT team:
We have analysed the first 6 orbits of the XRT data obtained for GRB 060804 (trigger 222546). Using these 4340 seconds of data, we find a refined position of:
```
RA(J2000)  =  07 28 49.40
Dec(J2000) = -27 12 58.7
```
with an uncertainty of 3.6 arcsec (90% containment). This is 0.2 arcsec from the initial XRT position stated in GCN 5394 (Ziaeepour et al.) and 53.8 arcsec from the refined BAT position in GCN 5395 (Tueller et al.)
The X-ray afterglow was sufficiently faint for the XRT to collect data only in Photon Counting mode. During the first orbit, the count rate remained close to constant, at ~1.5 count s^-1. Orbits 2-6, however, show a power-law decay, with a slope alpha = 0.86 +/- 0.22.
There is no evidence for spectral evolution between the first orbit (where the light-curve is flat) and the later decay, with the spectrum being well fitted with a simple power-law of Gamma = 2.24 +/- 0.22, with the Galactic absorbing column of 5.34e21 cm^-2; no excess NH is required. Between 130 and 700 seconds after the burst, the 0.3-10 keV observed (unabsorbed) flux was 6.95e-11 (1.44e-10) erg cm^-2 s^-1.
If the afterglow continues to decay at the same rate, the count rate at 24 hours is predicted to be 0.012 count s^-1, corresponding to an observed (unabsorbed) flux of 6.02e-13 (1.25e-12).
This circular is an official product of the Swift-XRT team.
GCN Circular #5397
S. B. Pandey, M. De Pasquale, M. J. Page and H.Z. Ziaeepour (UCL-MSSL) report on behalf of the Swift/UVOT team:
The Swift UVOT began taking settled exposures on the field of the long duration GRB 060804 (BAT Trigger #222546), 128s after the BAT trigger (Ziaeepour et al., GCN Circ. 5394). The optical afterglow candidate (RA(J2000) = 07h 28m 49.36s Dec(J2000) = -27d 12' 56.7") reported by Ziaeepour et al. 2006 (GCN Circ. 5394) is clearly detected in early frames. The fading behaviour of the candidate before the later frames confirms that it is the afterglow of GRB 060804. Detections in the initial V and White images, and 3-sigma upper limits in the later, coadded images are listed below.
```
Filter  T_range(s)    Exposure (s)    Magnitude

White   126-225         98            17.9+-0.1
V       231-631         393           17.7+-0.1
```
```
Filter  T_range(s)    Exposure (s)    3-sigma UL

White   5211-12280      253           > 20.1
V       5621-5820       197           > 19.4
B       709-12219       944           > 20.5
U       685-18065       896           > 19.9
UVW1    661-15696       408           > 19.8
UVM2    637-6025        216           > 19.5
UVW2    5417-21845      747           > 19.7
```
T_range is calculated from the time of the trigger. We caution that photometry of this afterglow is complicated by the presence of a nearby source.
These measurements have not been corrected for the estimated Galactic reddening of E_(B-V) = 0.657 mag (Schlegel et al. 1998). We caution that the extinction estimate for this burst, which has |Galactic latitude| < 5 deg, is unreliable.

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Jochen Greiner, last update: 04-Aug-2006 [Disclaimer]