Gamma-ray Burst 060908

(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 08 Sep 06 08:57:36 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     228581,   Seg_Num: 0
GRB_RA:           31.835d {+02h 07m 20s} (J2000),
                  31.920d {+02h 07m 41s} (current),
                  31.193d {+02h 04m 46s} (1950)
GRB_DEC:          +0.370d {+00d 22' 14"} (J2000),
                  +0.402d {+00d 24' 08"} (current),
                  +0.133d {+00d 07' 59"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       6439 [cnts]    Image_Peak=240 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   147     E_range: 25-100 keV
BKG_INTEN:       41524 [cnts]
BKG_TIME:        32230.56 SOD {08:57:10.56} UT
BKG_DUR:         8 [sec]
GRB_DATE:        13986 TJD;   251 DOY;   06/09/08
GRB_TIME:        32242.34 SOD {08:57:22.34} UT
GRB_PHI:          89.29 [deg]
GRB_THETA:        26.39 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     16.52 [sigma]
IMAGE_SIGNIF:    8.73 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +2 +11  +0  +0 +70  +1 
SUN_POSTN:       166.72d {+11h 06m 53s}   +5.69d {+05d 41' 09"}
SUN_DIST:        134.46 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.39d {+23h 37m 32s}   -2.63d {-02d 37' 40"}
MOON_DIST:        37.65 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.59,-57.00 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       29.80,-11.76 [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 = 268.71,19.81 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 08:59:02 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     228581,   Seg_Num: 0
GRB_RA:           31.8255d {+02h 07m 18.1s} (J2000),
                  31.9113d {+02h 07m 38.7s} (current),
                  31.1844d {+02h 04m 44.2s} (1950)
GRB_DEC:          +0.3416d {+00d 20' 29.7"} (J2000),
                  +0.3732d {+00d 22' 23.5"} (current),
                  +0.1042d {+00d 06' 15.2"} (1950)
GRB_ERROR:       6.1 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       25 [cnts]
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32314.02 SOD {08:58:34.02} UT,   71.7 [sec] since BAT Trigger Time
CENTROID_X:      348.83,  raw= 349  [pixels]
CENTROID_Y:      248.66,  raw= 249  [pixels]
ROLL:            81.63 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -118.17
GRB_POS_XRT_Z:   112.06
IMAGE_URL:       sw00228581000msxps_rw.img
SUN_POSTN:       166.72d {+11h 06m 53s}   +5.69d {+05d 41' 08"}
SUN_DIST:        134.48 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.40d {+23h 37m 36s}   -2.62d {-02d 37' 14"}
MOON_DIST:        37.62 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.60,-57.03 [deg] galactic lon,lat of the burst
ECL_COORDS:       29.78,-11.79 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 09:08:43 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.854d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
POINT_ROLL:      81.628d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32427.54 SOD {09:00:27.54} UT,   185.2 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.727
N_STARS:         90
X_OFFSET:        380 [pixels]
Y_OFFSET:        873 [pixels]
X_MAX:           1339 [pixels]
Y_MAX:           1832 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00228581000msufc0185.fits
SUN_POSTN:       166.73d {+11h 06m 55s}   +5.68d {+05d 40' 58"}
SUN_DIST:        134.45 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.49d {+23h 37m 57s}   -2.57d {-02d 34' 19"}
MOON_DIST:        37.56 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 09:02:14 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     228581,   Seg_Num: 0
GRB_RA:           31.835d {+02h 07m 20s} (J2000),
                  31.920d {+02h 07m 41s} (current),
                  31.193d {+02h 04m 46s} (1950)
GRB_DEC:          +0.370d {+00d 22' 14"} (J2000),
                  +0.402d {+00d 24' 08"} (current),
                  +0.133d {+00d 07' 59"} (1950)
GRB_DATE:        13986 TJD;   251 DOY;   06/09/08
GRB_TIME:        32242.34 SOD {08:57:22.34} UT
TRIGGER_INDEX:   147
GRB_PHI:          89.29 [deg]
GRB_THETA:        26.39 [deg]
DELTA_TIME:      -56.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     16.52 [sigma]
IMAGE_SIGNIF:    8.73 [sigma]
LC_URL:          sw00228581000msb.lc
SUN_POSTN:       166.72d {+11h 06m 54s}   +5.68d {+05d 41' 05"}
SUN_DIST:        134.47 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.43d {+23h 37m 43s}   -2.60d {-02d 36' 16"}
MOON_DIST:        37.60 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.59,-57.00 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       29.80,-11.76 [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 = 268.71,19.81 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 08:59:05 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     228581,   Seg_Num: 0
GRB_RA:           31.8255d {+02h 07m 18.1s} (J2000),
                  31.9113d {+02h 07m 38.7s} (current),
                  31.1844d {+02h 04m 44.2s} (1950)
GRB_DEC:          +0.3416d {+00d 20' 29.7"} (J2000),
                  +0.3732d {+00d 22' 23.5"} (current),
                  +0.1042d {+00d 06' 15.2"} (1950)
GRB_ERROR:       6.1 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       25 [cnts]
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32314.02 SOD {08:58:34.02} UT,   71.7 [sec] since BAT Trigger Time
CENTROID_X:      348.83,  raw= 349  [pixels]
CENTROID_Y:      248.66,  raw= 249  [pixels]
ROLL:            81.63 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -118.17
GRB_POS_XRT_Z:   112.06
IMAGE_URL:       sw00228581000msxps_rw.img
SUN_POSTN:       166.72d {+11h 06m 53s}   +5.69d {+05d 41' 08"}
SUN_DIST:        134.48 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.40d {+23h 37m 36s}   -2.62d {-02d 37' 13"}
MOON_DIST:        37.62 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.60,-57.03 [deg] galactic lon,lat of the burst
ECL_COORDS:       29.78,-11.79 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 09:00:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.851d {+02h 07m 24s} (J2000)
POINT_DEC:        +0.379d {+00d 22' 43"} (J2000)
POINT_ROLL:      81.628d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32322.27 SOD {08:58:42.27} UT,   79.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.758
N_STARS:         94
X_OFFSET:        376 [pixels]
Y_OFFSET:        656 [pixels]
X_MAX:           1335 [pixels]
Y_MAX:           1615 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00228581000msufc0079.fits
SUN_POSTN:       166.72d {+11h 06m 54s}   +5.68d {+05d 41' 06"}
SUN_DIST:        134.45 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.41d {+23h 37m 40s}   -2.61d {-02d 36' 43"}
MOON_DIST:        37.63 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.60,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 08:59:02 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     228581,   Seg_Num: 0
GRB_RA:           31.8255d {+02h 07m 18.1s} (J2000),
                  31.9113d {+02h 07m 38.7s} (current),
                  31.1844d {+02h 04m 44.2s} (1950)
GRB_DEC:          +0.3416d {+00d 20' 29.7"} (J2000),
                  +0.3732d {+00d 22' 23.5"} (current),
                  +0.1042d {+00d 06' 15.2"} (1950)
GRB_ERROR:       6.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       4.98e-10 [erg/cm2/sec]
GRB_SIGNIF:      5.00 [sigma]
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32314.02 SOD {08:58:34.02} UT,   71.7 [sec] since BAT Trigger Time
TAM[0-3]:        327.63 237.21 261.26 243.42
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       166.72d {+11h 06m 53s}   +5.69d {+05d 41' 08"}
SUN_DIST:        134.48 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.40d {+23h 37m 36s}   -2.62d {-02d 37' 14"}
MOON_DIST:        37.62 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.60,-57.03 [deg] galactic lon,lat of the burst
ECL_COORDS:       29.78,-11.79 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 09:10:14 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.854d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
ROLL:            81.628d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32427.54 SOD {09:00:27.54} UT,   185.2 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     179398828
X_OFFSET:        700 [pixels]
Y_OFFSET:        1193 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       860
Y_GRB_POS:       1353
BINNING_INDEX:   1
IM_URL:          sw00228581000msuni0185.fits
SUN_POSTN:       166.73d {+11h 06m 55s}   +5.68d {+05d 40' 57"}
SUN_DIST:        134.45 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.50d {+23h 38m 01s}   -2.56d {-02d 33' 51"}
MOON_DIST:        37.54 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position 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 08 Sep 06 09:12:56 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     228581,   Seg_Num: 0
GRB_RA:           31.8264d {+02h 07m 18.33s} (J2000),
                  31.9122d {+02h 07m 38.92s} (current),
                  31.1853d {+02h 04m 44.47s} (1950)
GRB_DEC:          +0.3420d {+00d 20' 31.2"} (J2000),
                  +0.3736d {+00d 22' 24.9"} (current),
                  +0.1046d {+00d 06' 16.6"} (1950)
GRB_ERROR:       0.4 [arcsec radius, statistical only]
GRB_MAG:         15.10 +/- 0.50 [mag]
FILTER:          10, White
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32322.00 SOD {08:58:42.00} UT,   79.7 [sec] since BAT Trigger Time
SUN_POSTN:       166.73d {+11h 06m 55s}   +5.68d {+05d 40' 54"}
SUN_DIST:        134.49 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.53d {+23h 38m 07s}   -2.55d {-02d 33' 03"}
MOON_DIST:        37.49 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.60,-57.03 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:       29.78,-11.79 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.

GCN Circular #5544
P. A. Evans (U Leicester), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), O. Godet (U Leicester), C. Guidorzi (Univ Bicocca&INAF-OAB), J. A. Kennea (PSU), A. N. Morgan (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL), P. Romano (INAF-OAB), G. Sato (GSFC/ISAS), M. Stamatikos (NASA/ORAU) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team:
At 08:57:22 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 060908 (trigger=228581). Swift slewed immediately to the burst. The BAT on-board calculated location is RA,Dec 31.835, +0.370 {02h 07m 20s, +00d 22' 14"} (J2000) with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows 3 overlapping peaks starting at ~T-10 sec and then a 4th peak lasting until T+12 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~T+2 sec after the trigger.
The XRT began observing the field at 08:58:34 UT, 72 seconds after the BAT trigger. XRT found a fading and uncatalogued X-ray source located at RA(J2000) = 02h 07m 18.1s, Dec(J2000) = +00d 20' 29.1", with an estimated uncertainty of 3.8 arcseconds (90% confidence radius). This location is 108 arcseconds from the BAT on-board position, within the BAT error circle. The initial flux in the 2.5s image was 5.0e-10 erg/cm2/s (0.2-10 keV).
UVOT took a finding chart exposure of 100 seconds with the White (160-650 nm) filter starting 80 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at (RA,DEC) (J2000) of (31.8265,0.3420) or (02h07m18.36s,+00o20'31.2") with a 1-sigma error radius of about 0.7 arc sec. This position is 3.8 arc sec. from the center of the XRT error circle. The estimated magnitude is 15.1 with a 1-sigma error of about 0.5 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.03.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 09:09:59 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.854d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
ROLL:            81.628d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32427.54 SOD {09:00:27.54} UT,   185.2 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     179398828
X_OFFSET:        700 [pixels]
Y_OFFSET:        1193 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       860
Y_GRB_POS:       1353
BINNING_INDEX:   1
IM_URL:          sw00228581000msuni0185.fits
SUN_POSTN:       166.73d {+11h 06m 55s}   +5.68d {+05d 40' 57"}
SUN_DIST:        134.45 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.50d {+23h 38m 00s}   -2.57d {-02d 33' 56"}
MOON_DIST:        37.55 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 09:09:08 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.854d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
POINT_ROLL:      81.628d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32427.54 SOD {09:00:27.54} UT,   185.2 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        1.727
N_STARS:         90
X_OFFSET:        380 [pixels]
Y_OFFSET:        873 [pixels]
X_MAX:           1339 [pixels]
Y_MAX:           1832 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00228581000msufc0185.fits
SUN_POSTN:       166.73d {+11h 06m 55s}   +5.68d {+05d 40' 58"}
SUN_DIST:        134.45 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.49d {+23h 37m 58s}   -2.57d {-02d 34' 11"}
MOON_DIST:        37.55 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [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 08 Sep 06 09:01:10 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.851d {+02h 07m 24s} (J2000)
POINT_DEC:        +0.379d {+00d 22' 43"} (J2000)
POINT_ROLL:      81.628d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32322.27 SOD {08:58:42.27} UT,   79.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.758
N_STARS:         94
X_OFFSET:        376 [pixels]
Y_OFFSET:        656 [pixels]
X_MAX:           1335 [pixels]
Y_MAX:           1615 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00228581000msufc0079.fits
SUN_POSTN:       166.72d {+11h 06m 54s}   +5.68d {+05d 41' 06"}
SUN_DIST:        134.45 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.42d {+23h 37m 40s}   -2.61d {-02d 36' 36"}
MOON_DIST:        37.63 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.60,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [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 08 Sep 06 09:02:29 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.851d {+02h 07m 24s} (J2000)
POINT_DEC:        +0.379d {+00d 22' 43"} (J2000)
ROLL:            81.628d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32322.27 SOD {08:58:42.27} UT,   79.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     179398723
X_OFFSET:        700 [pixels]
Y_OFFSET:        1193 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       860
Y_GRB_POS:       1353
BINNING_INDEX:   1
IM_URL:          sw00228581000msuni0079.fits
SUN_POSTN:       166.72d {+11h 06m 54s}   +5.68d {+05d 41' 04"}
SUN_DIST:        134.45 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.43d {+23h 37m 43s}   -2.60d {-02d 36' 12"}
MOON_DIST:        37.62 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.60,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the XRT Position 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 08 Sep 06 09:02:08 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.851d {+02h 07m 24s} (J2000)
POINT_DEC:        +0.379d {+00d 22' 43"} (J2000)
ROLL:            81.628d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  32322.27 SOD {08:58:42.27} UT,   79.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     179398723
X_OFFSET:        700 [pixels]
Y_OFFSET:        1193 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       860
Y_GRB_POS:       1353
BINNING_INDEX:   1
IM_URL:          sw00228581000msuni0079.fits
SUN_POSTN:       166.72d {+11h 06m 54s}   +5.68d {+05d 41' 05"}
SUN_DIST:        134.45 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.43d {+23h 37m 43s}   -2.61d {-02d 36' 18"}
MOON_DIST:        37.62 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.60,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the XRT Position Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 09:18:43 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.853d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
POINT_ROLL:      81.629d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  33104.77 SOD {09:11:44.77} UT,   862.4 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        3.129
N_STARS:         64
X_OFFSET:        380 [pixels]
Y_OFFSET:        873 [pixels]
X_MAX:           1339 [pixels]
Y_MAX:           1832 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00228581000msufc0862.fits
SUN_POSTN:       166.73d {+11h 06m 56s}   +5.68d {+05d 40' 49"}
SUN_DIST:        134.46 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.58d {+23h 38m 20s}   -2.52d {-02d 31' 18"}
MOON_DIST:        37.46 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 09:19:05 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.853d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
POINT_ROLL:      81.629d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  33104.77 SOD {09:11:44.77} UT,   862.4 [sec] since BAT Trigger Time
FILTER:          3, V
BKG_MEAN:        3.129
N_STARS:         64
X_OFFSET:        380 [pixels]
Y_OFFSET:        873 [pixels]
X_MAX:           1339 [pixels]
Y_MAX:           1832 [pixels]
DET_THRESH:      15
PHOTO_THRESH:    8
SL_URL:          sw00228581000msufc0862.fits
SUN_POSTN:       166.73d {+11h 06m 56s}   +5.68d {+05d 40' 49"}
SUN_DIST:        134.46 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.59d {+23h 38m 21s}   -2.52d {-02d 31' 11"}
MOON_DIST:        37.46 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [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 08 Sep 06 09:20:19 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.853d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
ROLL:            81.629d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  33104.77 SOD {09:11:44.77} UT,   862.4 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     179399506
X_OFFSET:        699 [pixels]
Y_OFFSET:        1192 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       859
Y_GRB_POS:       1352
BINNING_INDEX:   1
IM_URL:          sw00228581000msuni0862.fits
SUN_POSTN:       166.74d {+11h 06m 57s}   +5.68d {+05d 40' 48"}
SUN_DIST:        134.46 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.60d {+23h 38m 23s}   -2.51d {-02d 30' 49"}
MOON_DIST:        37.45 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [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 08 Sep 06 09:20:33 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.853d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
ROLL:            81.629d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  33104.77 SOD {09:11:44.77} UT,   862.4 [sec] since BAT Trigger Time
FILTER:          3, V
EXPOSURE_ID:     179399506
X_OFFSET:        699 [pixels]
Y_OFFSET:        1192 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       859
Y_GRB_POS:       1352
BINNING_INDEX:   1
IM_URL:          sw00228581000msuni0862.fits
SUN_POSTN:       166.74d {+11h 06m 57s}   +5.68d {+05d 40' 47"}
SUN_DIST:        134.46 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.60d {+23h 38m 24s}   -2.51d {-02d 30' 45"}
MOON_DIST:        37.44 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [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 08 Sep 06 09:21:02 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.853d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
POINT_ROLL:      81.629d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  33512.81 SOD {09:18:32.81} UT,   1270.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.613
N_STARS:         45
X_OFFSET:        380 [pixels]
Y_OFFSET:        873 [pixels]
X_MAX:           1339 [pixels]
Y_MAX:           1832 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00228581000msufc1270.fits
SUN_POSTN:       166.74d {+11h 06m 57s}   +5.68d {+05d 40' 47"}
SUN_DIST:        134.46 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.60d {+23h 38m 25s}   -2.51d {-02d 30' 36"}
MOON_DIST:        37.44 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 08 Sep 06 09:21:29 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.853d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
POINT_ROLL:      81.629d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  33512.81 SOD {09:18:32.81} UT,   1270.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        3.613
N_STARS:         45
X_OFFSET:        380 [pixels]
Y_OFFSET:        873 [pixels]
X_MAX:           1339 [pixels]
Y_MAX:           1832 [pixels]
DET_THRESH:      16
PHOTO_THRESH:    9
SL_URL:          sw00228581000msufc1270.fits
SUN_POSTN:       166.74d {+11h 06m 57s}   +5.68d {+05d 40' 46"}
SUN_DIST:        134.46 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.61d {+23h 38m 26s}   -2.51d {-02d 30' 28"}
MOON_DIST:        37.43 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [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 08 Sep 06 09:22:28 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.853d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
ROLL:            81.629d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  33512.81 SOD {09:18:32.81} UT,   1270.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     179399914
X_OFFSET:        699 [pixels]
Y_OFFSET:        1192 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       859
Y_GRB_POS:       1352
BINNING_INDEX:   1
IM_URL:          sw00228581000msuni1270.fits
SUN_POSTN:       166.74d {+11h 06m 57s}   +5.68d {+05d 40' 46"}
SUN_DIST:        134.46 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.62d {+23h 38m 28s}   -2.50d {-02d 30' 10"}
MOON_DIST:        37.43 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [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 08 Sep 06 09:22:45 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     228581,   Seg_Num: 0
POINT_RA:         31.853d {+02h 07m 25s} (J2000)
POINT_DEC:        +0.378d {+00d 22' 41"} (J2000)
ROLL:            81.629d
IMG_START_DATE:  13986 TJD;   251 DOY;   06/09/08
IMG_START_TIME:  33512.81 SOD {09:18:32.81} UT,   1270.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     179399914
X_OFFSET:        699 [pixels]
Y_OFFSET:        1192 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       859
Y_GRB_POS:       1352
BINNING_INDEX:   1
IM_URL:          sw00228581000msuni1270.fits
SUN_POSTN:       166.74d {+11h 06m 57s}   +5.68d {+05d 40' 45"}
SUN_DIST:        134.46 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      354.62d {+23h 38m 29s}   -2.50d {-02d 30' 05"}
MOON_DIST:        37.42 [deg]
MOON_ILLUM:      99 [%]
GAL_COORDS:      159.61,-56.98 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:       29.82,-11.76 [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 Circular #5545
M. Nysewander, D. Reichart, K. Ivarsen, A. Foster, A. LaCluyze, J.A. Crain, report:
SkyNet observed the localization of GRB 060908 with four of the PROMPT telescopes starting at 08:58:25 UT.
We note a very bright uncatalogued rapidly fading source at approximately 02:07:19, +00:20:30.
In the r' initial image beginning at 08:59:07 UT, 105 s after the trigger, the source is at approximately r ~ 15.
Further analysis is underway.
GCN Circular #5546
L.A. Antonelli, S. Covino, V. Testa, E. Palazzi, E. Molinari, P. D'Avanzo, G. Chincarini, F.M. Zerbi, G. Tosti, F. Vitali, P. Conconi, G. Cutispoto, G. Malaspina, L. Nicastro, E. Meurs, and P. Goldoni report on behalf of the REM/ROSS team:
The robotic 60-cm REM telescope, located at La Silla (Chile), observed automatically the field of GRB 060908 (Evans et al., GCN 5544) with ROSS optical camera. Observations started at 09:06:21 UT, about 7 min after the burst, in R, I and V band.
An uncatalogued fading source was observed in all filters at:
```
RA: 02:07:18.3
DEC +00:20:31
```
This position is consistent with the one reported in GCN 5544 and GCN 5545.
In the R initial image the source is at approximately R ~ 17 in 20 sec exposure time.
Further analysis is in progress.
GCN Circular #5550
Richard J. Cool (Arizona), Daniel J. Eisenstein (Arizona), David W. Hogg (NYU), Michael R. Blanton (NYU), David J. Schlegel (LBNL), J. Brinkmann (APO), Donald Q. Lamb (Chicago), Donald P. Schneider (PSU), and Daniel E. Vanden Berk (PSU) report:
The Sloan Digital Sky Survey (SDSS) imaged the field of burst GRB060908 prior to the burst. As these data should be useful as a pre-burst comparison and for calibrating photometry, we are supplying the images and photometry measurements for this GRB field to the community.
Data from the SDSS, including 5 FITS images, 3 JPGS, and 3 files of photometry and astrometry, are being placed at http://mizar.as.arizona.edu/~grb/public/GRB060908
We supply FITS images in each of the 5 SDSS bands of a 8'x8' region centered on the GRB position (ra=31.8350 (02:07:20.4), dec=0.370000 (00:22:12.0); Swift-BAT TRIGGER 228581), as well as 3 gri color-composite JPGs (with different stretches). The units in the FITS images are nanomaggies per pixel. A pixel is 0.396 arcsec on a side. A nanomaggie is a flux-density unit equal to 10^-9 of a magnitude 0 source or, to the extent that SDSS is an AB system, 3.631e-6 Jy. The FITS images have WCS astrometric information.
In the file GRB060908_sdss.calstar.dat, we report photometry and astrometry of 37 bright stars (r<20.5) within 15' of the burst location. The magnitudes presented in this file are asinh magnitudes as are standard in the SDSS (Lupton 1999, AJ, 118, 1406). Beware that some of these stars are not well-detected in the u-band; use the errors and object flags to monitor data quality.
In the files GRB060908_sdss.objects_flux.dat and GRB060908_sdss.objects_magnitudes.dat, we report photometry of 1285 objects detected within 6' of the GRB position. We have removed saturated objects and objects with model magnitudes fainter than 23.0 in the r-band. The fluxes listed in GRB060908_sdss.objects_flux.dat are in nanomaggies while the magnitudes listed in GRB060908_sdss.objects_magnitudes.dat are asinh magnitudes.
All quantities reported are standard SDSS photometry, meaning that they are very close to AB zeropoints and magnitudes are quoted in asinh magnitudes. Photometric zeropoints are known to about 2% rms. None of the photometry is corrected for dust extinction. The Schlegel, Finkbeiner, and Davis (1998) predictions for this region are A_U=0.146 mag, A_g=0.107 mag, A_r = 0.078 mag, A_i=0.059 mag, and A_z=0.042 mag.
The file GRB060908_sdss.spectro.dat contains a list of the 11 objects with SDSS spectroscopy within 6 arcminutes of the GRB position. In addition to the redshift and 1-sigma error for each object, this file also lists the object spectroscopic classification.
SDSS astrometry is generally better than 0.1 arcsecond per coordinate. Users requiring high precision astrometry should take note that the SDSS astrometric system can differ from other systems such as those used in other notices; we have not checked the offsets in this region.
More detailed information pertaining to our SDSS GRB releases can be found in our initial data release paper (Cool et al. 2006, astro-ph/0601218). See the SDSS DR4 documentation for more details: http://www.sdss.org/dr5.
These data have been reduced using a slightly different pipeline than that used for SDSS public data releases. We cannot guarantee that the values here will exactly match those in the data release in which these data are included. In particular, we expect the photometric calibrations to differ by of order 0.01 mag.
This note may be cited, but please also cite the SDSS data release paper, Adelman-McCarthy et al. (2006, ApJS, 162, 38), when using the data or referring to the technical documentation.
GCN Circular #5551
D. Palmer (LANL), L. Barbier (GSFC), S. D. Barthelmy (GSFC), J. Cummings (GSFC/UMD), P. A. Evans (U Leicester), E. Fenimore (LANL), N. Gehrels (GSFC), D. Hullinger (BYU-Idaho), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD), 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+302 sec from recent telemetry downlinks, we report further analysis of BAT GRB 060908 (trigger #228581) (Evans, et al., GCN Circ. 5544). The BAT ground-calculated position is RA,Dec = 31.820, 0.330 deg {2h 7m 16.8s,+0d 19' 48.9"} (J2000) +- 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 46%.
The lighcurve has 3 overlapping peaks starting at ~T-12 sec then briefly returning to background at T+6 sec. The second peak has a maximium at T+10 sec and ends at T+14 sec. T90 (15-350 keV) is 19.3 +- 0.3 sec (estimated error including systematics).
The time-averaged spectrum from T-17.5 to T+15.1 is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.33 +- 0.07. The fluence in the 15-150 keV band is 2.9 +- 0.1 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.97 sec in the 15-150 keV band is 3.2 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
GCN Circular #5552
K. Wiersema (University of Amsterdam), C.C. Thoene (DARK Cosmology Centre) and E. Rol (University of Leicester) report:
We observed the position of GRB 060908 using the Danish 1.5m telescope equipped with DFOSC, in R band. The optical transient (Evans et al, GCN 5544) is detected in all our exposures.
We performed photometry with respect to a nearby USNO-B1.0 star 0903-0022606, for which we assume R = 18.29. The reported error in our magnitude is therefore only the error in the photometry of the transient. We find R = 21.57 +/- 0.04, 46 minutes after the trigger.
During our observations between 36 and 70 minutes after the trigger, the optical transient is clearly decaying: a power law fit to our data results in a decay index of 1.07 +/- 0.11. The magnitude and decay rate suggest that the decay slowed down somewhat, after an initial steep decline.
GCN Circular #5553
A. N. Morgan (PSU), D. E. Vanden Berk (PSU), P. Brown (PSU) and P. A. Evans (U Leicester) report on behalf of the Swift UVOT team:
The Swift/UVOT began observations of GRB 060908 at 08:58:42 UT, ~80 seconds after the initial Swift BAT trigger (Evans et al., GCN Circ. 5544). An optical counterpart was detected with the V filter at a position RA(J2000) = (02h 07m 18.36s,+00d 20' 31.2") to within 0.7".
An optical afterglow was detected in the White, V, B, U, and UVW1 filters.
The best estimate for the photometric redshift is z=1.62 assuming an SMC extinction law with E(B-V)=0.05, but it is poorly constrained. Values range from z=0.26-2.20 for a 90% confidence range.
The photometry was performed using a 6 arcsec radius aperture and is reported below:
```
Filter  T_range(s)    Exp. (s)   Magnitude
White   80-179        99.8       15.06 +/- 0.03
White   5839-6038     199.8      19.57 +/- 0.22

V       185-584       399.8      16.85 +/- 0.05
V       4816-6448     399.6      19.44 +/- 0.36

B       663-820       19.6       18.41 +/- 0.31
B       5635-7129     262.5      > 20.03 (3.0-sigma)

U       639-658       19.7       17.01 +/- 0.16
U       786-805       19.8       17.99 +/- 0.32

UVW1    615-782       39.6       18.61 +/- 0.35
UVW1    5226-6857     399.6      > 20.24 (3.0-sigma)

UVM2    591-758       39.6       > 18.57 (3.0-sigma)
UVM2    5021-6652     399.6      > 20.54 (3.0-sigma)

UVW2    691-858       39.6       > 19.07 (3.0-sigma)
UVW2    4612-6243     399.6      > 20.71 (3.0-sigma)
```
The values quoted above are not corrected for the expected Galactic extinction of E(B-V)=0.03.
GCN Circular #5554
P.A. Evans, A.P. Beardmore, O. Godet and K.L. Page (U. Leicester) report on behalf of the Swift/XRT team:
We have analysed the first 2 orbits of Swift data of GRB 060908 (Evans et al., GCN 5544), totalling 100 s of data in Window Timing mode (WT) and 2.5 ks in Photon Counting mode (PC).
The PC mode image provides a refined XRT position of
```
RA(J2000)   =  02 07 18.21
Dec(J2000)  = +00 20 28.8
```
with an error of 3.6" (90% confidence). This position is within 1.5" of the initial XRT position, and 3.4" from the UVOT position, reported in GCN 5554.
Spectral fits to the first orbit of data suggest an absorption column in excess of the Galactic value (2.4e20 cm^-2). The WT data yielded 8.0+4.9/-4.0 e20 cm^-2 and the PC mode data gave 6.4+3.4/-3.0 e20 cm^-2.
There is also evidence for spectral evolution during the first orbit: the WT mode photon index was 2.43 (+0.30, -0.26), while the PC mode photon index was 1.95 (+0.15,-0.14). The observed PC mode flux was 7.5e-11 erg/s/cm^2 during the first orbit; which translates to an unabsorbed flux of 8.9e-11 erg/s/cm^2
The lightcurve of the first 2 orbits (T0+78 to T0+6600) can be modelled with a single power-law, and a flare at around 800s. The decay slope is 1.11 +/-0.06, and we thus predict a count rate of 0.004 counts per second 24 hours after the trigger. This translates to a flux of 1.56e-13 erg/s/cm^2, or an unabsorbed flux of 1.85e-13 erg/s/cm^2.
This circular is an official product of the Swift XRT Team.
GCN Circular #5555
E. Rol (U of Leicester), P. Jakobsson (U of Hertfordshire), N. Tanvir (U of Leicester), A. Levan (U of Hertfordshire), report for a larger collaboration:
We obtained a spectrum of GRB 060908 (Evans et al, GCN 5544) with Gemini-North/GMOS, for a total of 30 minutes starting approximately 2 hours post burst. We identify absorption lines of CIV (1548, 1551) and SiII (1304), and possibly AlIII (1863), at a redshift of z = 2.43 +/- 0.05.
We thank the Gemini staff for their support with the observations.
GCN Circular #5556
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 060908 (GCN#5544) using the VLA at a frequency of 8.46 GHz and starting at 7.55 UT on Sept 1st, a day after the burst. There is no detection of the GRB with 2-sigma upper limit of 51 microJy.
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN Circular #5653
M. Andreev, A. Sergeev (Terskol Branch of Institute of Astronomy), A. Kurenya (Baksan Neutrino Observatory), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report:
We observed the afterglow of GRB060908 (Evans et al., GCN 5544) with 2m telescope of Terskol Observatory on Sep. 08 (UT) 20:51:45 - 21:14:45. We detect the afterglow on a combined image of 20x60 s exposure. Based on USNO A2.0 field stars we estimate brightness of the optical transient:
Mid time (UT), Exposure, R_mag
Sep. 08.877 20x60 s 20.70 +/- 0.27
It should be noted that R magnitude of the star (USNO-B1.0 0903-0022606 R = 18.29) used in GCN 5552 (Wiersema et. al) is inconsistent with the R-magnitude of the same star USNO A2.0 (0900-00494220 R = 14.9). R-magnitudes of other field stars of the two catalogs USNO-B1.0 and USNO A2.0 are also inconsistent by ~2.9 mag in average.
The message may be cited.
GCN Circular #5674
Christina C. Thoene (DARK Cosmology Centre), Christina Henriksen (DARK, NOT) and Klaas Wiersema (Univ. of Amsterdam) report:
We observed the field of GRB060908 on Sep. 21 and 23 with ALFOSC at the NOT on La Palma in V, R and i under variable conditions. Near the position of the afterglow (GCN 5544), we detect a faint, extended source in stacked images in V (7x600s) and R (10x600s), which we assume to be the host galaxy of GRB060908. The possible host is not visible in 7x600s stacked images in the i band which might be due to severe fringing in the i band images. Photometry of the source gives values of V=24.9 +-0.1, R=25.12 +-0.05 and i>24.6 +-0.2 using photometric zeropoints from the NOT/ALFOSC webpage.
An image of the host in the R-band can be found at www.astro.ku.dk/~cthoene/GRBs/
Redshift of z = 1.8836
0907.3449 from 20 Jul 2009
Fynbo et al: Low-Resolution Spectroscopy of Gamma-ray Burst Optical Afterglows: Biases in the Swift Sample and Characterization of the Absorbers
Abstract: (Abridged). We present a sample of 77 optical afterglows (OAs) of Swift detected GRBs for which spectroscopic follow-up observations have been secured. We provide linelists and equivalent widths for all detected lines redward of Ly-alpha. We discuss to what extent the current sample of Swift bursts with OA spectroscopy is a biased subsample of all Swift detected GRBs. For that purpose we define an X-ray selected sample of Swift bursts with optimal conditions for ground-based follow up from the period March 2005 to September 2008; 146 bursts fulfill our sample criteria. We derive the redshift distribution for this sample and conclude that less than 19% of Swift bursts are at z>7. We compare the high energy properties for three sub-samples of bursts in the sample: i) bursts with redshifts measured from OA spectroscopy, ii) bursts with detected OA, but no OA-based redshift, and iii) bursts with no detection of the OA. The bursts in group i) have significantly less excess X-ray absorption than bursts in the other two groups. In addition, the fraction of dark bursts is 14% in group i), 38% in group ii) and > 39% in group iii). From this we conclude that the sample of GRBs with OA spectroscopy is not representative for all Swift bursts, most likely due to a bias against the most dusty sight-lines. Finally, we characterize GRB absorption systems as a class and compare them to QSO absorption systems, in particular DLAs. On average GRB absorbers are characterized by significantly stronger EWs for HI as well as for both low and high ionization metal lines than what is seen in intervening QSO absorbers. Based on the z>2 bursts in the sample we place a 95% confidence upper limit of 7.5% on the mean escape fraction of ionizing photons from star-forming galaxies.
1007.4769 from 28 Jul 10
S. Covino et al.: Challenging GRB models through the broadband dataset of GRB060908
E. Cobb, A. Fernandez-Soto, D. A. Kann, D. Malesani, N. R. Tanvir, L. A. Antonelli, M. Bremer, A. J. Castro-Tirado, A. de Ugarte Postigo, E. Molinari, L. Nicastro, M. Stefanon, V. Testa, G. Tosti, F. Vitali, L. Amati, R. Chapman, P. Conconi, G. Cutispoto, J. P. U. Fynbo, P. Goldoni, C. Henriksen, K. D. Horne, G. Malaspina, E. J. A. Meurs, E. Pian, L. Stella, G. Tagliaferri, P. Ward, F. M. Zerbi
Context: Multiwavelength observations of gamma-ray burst prompt and afterglow emission are a key tool to disentangle the various possible emission processes and scenarios proposed to interpret the complex gamma-ray burst phenomenology.
Aims: We collected a large dataset on GRB060908 in order to carry out a comprehensive analysis of the prompt emission as well as the early and late afterglow.
Methods: Data from Swift-BAT, -XRT and -UVOT together with data from a number of different ground-based optical/NIR and millimeter telescopes allowed us to follow the afterglow evolution from about a minute from the high-energy event down to the host galaxy limit. We discuss the physical parameters required to model these emissions.
Results: The prompt emission of GRB060908 was characterized by two main periods of activity, spaced by a few seconds of low intensity, with a tight correlation between activity and spectral hardness. Observations of the afterglow began less than one minute after the high-energy event, when it was already in a decaying phase, and it was characterized by a rather flat optical/NIR spectrum which can be interpreted as due to a hard energy-distribution of the emitting electrons. On the other hand, the X-ray spectrum of the afterglow could be fit by a rather soft electron distribution.
Conclusions: GRB060908 is a good example of a gamma-ray burst with a rich multi-wavelength set of observations. The availability of this dataset, built thanks to the joint efforts of many different teams, allowed us to carry out stringent tests for various interpretative scenarios showing that a satisfactorily modeling of this event is challenging. In the future, similar efforts will enable us to obtain optical/NIR coverage comparable in quality and quantity to the X-ray data for more events, therefore opening new avenues to progress gamma-ray burst research.

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Jochen Greiner, last update: 28-Jul-2010 [Disclaimer]