Gamma-ray Burst 090809

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 09 Aug 09 17:31:54 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     359530,   Seg_Num: 0
GRB_RA:          328.645d {+21h 54m 35s} (J2000),
                 328.768d {+21h 55m 04s} (current),
                 328.004d {+21h 52m 01s} (1950)
GRB_DEC:          -0.083d {-00d 04' 59"} (J2000),
                  -0.038d {-00d 02' 14"} (current),
                  -0.320d {-00d 19' 11"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       15930 [cnts]    Image_Peak=339 [image_cnts]
TRIGGER_DUR:     4.096 [sec] 
TRIGGER_INDEX:   299     E_range: 25-100 keV
BKG_INTEN:       143372 [cnts]
BKG_TIME:        63019.01 SOD {17:30:19.01} UT
BKG_DUR:         40 [sec]
GRB_DATE:        15052 TJD;   221 DOY;   09/08/09
GRB_TIME:        63074.50 SOD {17:31:14.50} UT
GRB_PHI:          99.29 [deg]
GRB_THETA:        27.72 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     10.67 [sigma]
IMAGE_SIGNIF:    8.62 [sigma]
MERIT_PARAMS:     +1  +0  +0  +2  +2  -1  +0  +0 +95  +0 
SUN_POSTN:       139.70d {+09h 18m 48s}  +15.66d {+15d 39' 48"}
SUN_DIST:        161.99 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      356.92d {+23h 47m 42s}   +3.57d {+03d 34' 13"}
MOON_DIST:        28.37 [deg]
MOON_ILLUM:      88 [%]
GAL_COORDS:       57.96,-39.68 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      330.76, 11.87 [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 = 182.34,-10.92 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 09 Aug 09 17:33:17 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.660d {+21h 54m 38s} (J2000)
POINT_DEC:        -0.081d {-00d 04' 50"} (J2000)
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  63178.52 SOD {17:32:58.52} UT,   104.0 [sec] since BAT Trigger Time
COUNTS:          14    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:     Sun 09 Aug 09 17:35:07 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.660d {+21h 54m 38s} (J2000)
POINT_DEC:        -0.081d {-00d 04' 50"} (J2000)
POINT_ROLL:      29.111d
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  63182.02 SOD {17:33:02.02} UT,   107.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.521
N_STARS:         44
X_OFFSET:        360 [pixels]
Y_OFFSET:        524 [pixels]
X_MAX:           1319 [pixels]
Y_MAX:           1483 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00359530000msufc0107.fits
SUN_POSTN:       139.70d {+09h 18m 49s}  +15.66d {+15d 39' 46"}
SUN_DIST:        161.98 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      356.95d {+23h 47m 48s}   +3.58d {+03d 34' 57"}
MOON_DIST:        28.38 [deg]
MOON_ILLUM:      88 [%]
GAL_COORDS:       57.97,-39.69 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.78, 11.86 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 09 Aug 09 17:35:36 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.660d {+21h 54m 38s} (J2000)
POINT_DEC:        -0.081d {-00d 04' 50"} (J2000)
POINT_ROLL:      29.111d
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  63182.02 SOD {17:33:02.02} UT,   107.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.521
N_STARS:         44
X_OFFSET:        360 [pixels]
Y_OFFSET:        524 [pixels]
X_MAX:           1319 [pixels]
Y_MAX:           1483 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00359530000msufc0107.fits
SUN_POSTN:       139.70d {+09h 18m 49s}  +15.66d {+15d 39' 45"}
SUN_DIST:        161.98 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      356.95d {+23h 47m 49s}   +3.58d {+03d 35' 04"}
MOON_DIST:        28.38 [deg]
MOON_ILLUM:      88 [%]
GAL_COORDS:       57.97,-39.69 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.78, 11.86 [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:     Sun 09 Aug 09 17:36:30 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.660d {+21h 54m 38s} (J2000)
POINT_DEC:        -0.081d {-00d 04' 50"} (J2000)
ROLL:            29.111d
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  63182.02 SOD {17:33:02.02} UT,   107.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     271531987
X_OFFSET:        679 [pixels]
Y_OFFSET:        843 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       839
Y_GRB_POS:       1003
BINNING_INDEX:   1
IM_URL:          sw00359530000msuni0112.fits
SUN_POSTN:       139.70d {+09h 18m 49s}  +15.66d {+15d 39' 44"}
SUN_DIST:        161.98 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      356.96d {+23h 47m 50s}   +3.59d {+03d 35' 16"}
MOON_DIST:        28.39 [deg]
MOON_ILLUM:      88 [%]
GAL_COORDS:       57.97,-39.69 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.78, 11.86 [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:     Sun 09 Aug 09 17:36:48 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.660d {+21h 54m 38s} (J2000)
POINT_DEC:        -0.081d {-00d 04' 50"} (J2000)
ROLL:            29.111d
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  63182.02 SOD {17:33:02.02} UT,   107.5 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     271531987
X_OFFSET:        679 [pixels]
Y_OFFSET:        843 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       839
Y_GRB_POS:       1003
BINNING_INDEX:   1
IM_URL:          sw00359530000msuni0112.fits
SUN_POSTN:       139.70d {+09h 18m 49s}  +15.66d {+15d 39' 44"}
SUN_DIST:        161.98 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      356.96d {+23h 47m 51s}   +3.59d {+03d 35' 20"}
MOON_DIST:        28.39 [deg]
MOON_ILLUM:      88 [%]
GAL_COORDS:       57.97,-39.69 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.78, 11.86 [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:     Sun 09 Aug 09 17:35:07 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.660d {+21h 54m 38s} (J2000)
POINT_DEC:        -0.081d {-00d 04' 50"} (J2000)
POINT_ROLL:      29.111d
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  63182.02 SOD {17:33:02.02} UT,   107.5 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.521
N_STARS:         44
X_OFFSET:        360 [pixels]
Y_OFFSET:        524 [pixels]
X_MAX:           1319 [pixels]
Y_MAX:           1483 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw00359530000msufc0107.fits
SUN_POSTN:       139.70d {+09h 18m 49s}  +15.66d {+15d 39' 46"}
SUN_DIST:        161.98 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      356.95d {+23h 47m 48s}   +3.58d {+03d 34' 57"}
MOON_DIST:        28.38 [deg]
MOON_ILLUM:      88 [%]
GAL_COORDS:       57.97,-39.69 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.78, 11.86 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 09 Aug 09 17:37:00 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     359530,   Seg_Num: 0
GRB_RA:          328.645d {+21h 54m 35s} (J2000),
                 328.768d {+21h 55m 04s} (current),
                 328.004d {+21h 52m 01s} (1950)
GRB_DEC:          -0.083d {-00d 04' 59"} (J2000),
                  -0.038d {-00d 02' 14"} (current),
                  -0.320d {-00d 19' 11"} (1950)
GRB_DATE:        15052 TJD;   221 DOY;   09/08/09
GRB_TIME:        63074.50 SOD {17:31:14.50} UT
TRIGGER_INDEX:   299
GRB_PHI:          99.29 [deg]
GRB_THETA:        27.72 [deg]
DELTA_TIME:      52.00 [sec]
TRIGGER_DUR:     4.096 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     10.67 [sigma]
IMAGE_SIGNIF:    8.62 [sigma]
LC_URL:          sw00359530000msb.lc
SUN_POSTN:       139.70d {+09h 18m 49s}  +15.66d {+15d 39' 44"}
SUN_DIST:        161.99 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      356.96d {+23h 47m 51s}   +3.59d {+03d 35' 23"}
MOON_DIST:        28.41 [deg]
MOON_ILLUM:      88 [%]
GAL_COORDS:       57.96,-39.68 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      330.76, 11.87 [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 = 182.34,-10.92 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 09 Aug 09 17:38:00 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     359530,   Seg_Num: 0
GRB_RA:          328.6777d {+21h 54m 42.64s} (J2000),
                 328.8008d {+21h 55m 12.19s} (current),
                 328.0367d {+21h 52m 08.79s} (1950)
GRB_DEC:          -0.0846d {-00d 05' 04.5"} (J2000),
                  -0.0389d {-00d 02' 19.9"} (current),
                  -0.3216d {-00d 19' 17.8"} (1950)
GRB_ERROR:       4.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  63218.00 SOD {17:33:38.00} UT,   143.5 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       139.71d {+09h 18m 49s}  +15.66d {+15d 39' 43"}
SUN_DIST:        161.98 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      356.97d {+23h 47m 53s}   +3.59d {+03d 35' 37"}
MOON_DIST:        28.38 [deg]
MOON_ILLUM:      88 [%]
GAL_COORDS:       57.98,-39.71 [deg] galactic lon,lat of the burst
ECL_COORDS:      330.79, 11.85 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.

GCN Circular #9754
C. B. Markwardt (CRESST/GSFC/UMD), S. D. Barthelmy (GSFC), M. M. Chester (PSU), A. de Ugarte Postigo (INAF-OAB), N. Gehrels (NASA/GSFC), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU), N. P. M. Kuin (MSSL), W.B Landsman (GSFC), J. Mao (INAF-OAB), R. Margutti (Univ Bicocca&OAB), P. T. O'Brien (U Leicester), K. L. Page (U Leicester), P. Romano (INAF-IASFPA) and M. H. Siegel (PSU) report on behalf of the Swift Team:
At 17:31:14 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090809 (trigger=359530). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 328.645, -0.083 which is
```
   RA(J2000)  =  21h 54m 35s
   Dec(J2000) = -00d 04' 59"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a weak peak with a duration of about 10 sec. The peak count rate was ~900 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 17:32:58.5 UT, 104.0 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 328.67772, -0.08465 which is equivalent to:
```
   RA(J2000)  = 21h 54m 42.65s
   Dec(J2000) = -00d 05' 04.7"
```
with an uncertainty of 4.5 arcseconds (radius, 90% containment). This location is 117 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (6.08e+20 cm^-2, Kalberla et al. 2005), with an excess column of 2.5 (+2.71/-2.28) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 86 seconds with the White filter starting 107 seconds after the BAT trigger. A possible afterglow candidate has been found in the list of sources generated on-board, located at RA=328.68008 (21:54:43.22), dec=-0.08385 (-00:05:01.9), with an estimated White magnitude = 19.9 +/-0.4. The 2.7'x2.7' sub-image does not include the XRT position. No correction has been made for the expected extinction corresponding to E(B-V) of 0.10.
Burst Advocate for this burst is C. B. Markwardt (Craig.Markwardt AT nasa.gov). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 09 Aug 09 18:00:56 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     359530,   Seg_Num: 0
GRB_RA:          328.6800d {+21h 54m 43.20s} (J2000),
                 328.8031d {+21h 55m 12.74s} (current),
                 328.0390d {+21h 52m 09.35s} (1950)
GRB_DEC:          -0.0837d {-00d 05' 01.3"} (J2000),
                  -0.0380d {-00d 02' 16.7"} (current),
                  -0.3207d {-00d 19' 14.5"} (1950)
GRB_ERROR:       10.0 [arcsec radius, statistical only]
GRB_MAG:         19.89 +/- 0.40 [mag]
FILTER:          10, White
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  63185.00 SOD {17:33:05.00} UT,   110.5 [sec] since BAT Trigger Time
SUN_POSTN:       139.72d {+09h 18m 53s}  +15.66d {+15d 39' 27"}
SUN_DIST:        161.99 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      357.15d {+23h 48m 35s}   +3.68d {+03d 40' 52"}
MOON_DIST:        28.57 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:       57.98,-39.71 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      330.80, 11.85 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        Possible counterpart found in list of sources  
COMMENTS:        generated on-board.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 09 Aug 09 18:30:47 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.654d {+21h 54m 37s} (J2000)
POINT_DEC:        -0.119d {-00d 07' 09"} (J2000)
POINT_ROLL:      29.096d
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  66470.09 SOD {18:27:50.09} UT,   3395.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.549
N_STARS:         51
X_OFFSET:        571 [pixels]
Y_OFFSET:        305 [pixels]
X_MAX:           1530 [pixels]
Y_MAX:           1264 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00359530000msufc3395.fits
SUN_POSTN:       139.74d {+09h 18m 58s}  +15.65d {+15d 39' 05"}
SUN_DIST:        162.05 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      357.38d {+23h 49m 31s}   +3.80d {+03d 47' 42"}
MOON_DIST:        28.84 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:       57.92,-39.71 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.76, 11.83 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 09 Aug 09 18:30:47 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.654d {+21h 54m 37s} (J2000)
POINT_DEC:        -0.119d {-00d 07' 09"} (J2000)
POINT_ROLL:      29.096d
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  66470.09 SOD {18:27:50.09} UT,   3395.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.549
N_STARS:         51
X_OFFSET:        571 [pixels]
Y_OFFSET:        305 [pixels]
X_MAX:           1530 [pixels]
Y_MAX:           1264 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00359530000msufc3395.fits
SUN_POSTN:       139.74d {+09h 18m 58s}  +15.65d {+15d 39' 05"}
SUN_DIST:        162.05 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      357.38d {+23h 49m 31s}   +3.80d {+03d 47' 42"}
MOON_DIST:        28.84 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:       57.92,-39.71 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.76, 11.83 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 09 Aug 09 18:31:16 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.654d {+21h 54m 37s} (J2000)
POINT_DEC:        -0.119d {-00d 07' 09"} (J2000)
POINT_ROLL:      29.096d
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  66470.09 SOD {18:27:50.09} UT,   3395.6 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.549
N_STARS:         51
X_OFFSET:        571 [pixels]
Y_OFFSET:        305 [pixels]
X_MAX:           1530 [pixels]
Y_MAX:           1264 [pixels]
DET_THRESH:      13
PHOTO_THRESH:    7
SL_URL:          sw00359530000msufc3395.fits
SUN_POSTN:       139.74d {+09h 18m 58s}  +15.65d {+15d 39' 05"}
SUN_DIST:        162.05 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      357.38d {+23h 49m 32s}   +3.80d {+03d 47' 49"}
MOON_DIST:        28.85 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:       57.92,-39.71 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.76, 11.83 [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:     Sun 09 Aug 09 18:32:15 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.654d {+21h 54m 37s} (J2000)
POINT_DEC:        -0.119d {-00d 07' 09"} (J2000)
ROLL:            29.096d
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  66470.09 SOD {18:27:50.09} UT,   3395.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     271535275
X_OFFSET:        890 [pixels]
Y_OFFSET:        624 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1050
Y_GRB_POS:       784
BINNING_INDEX:   1
IM_URL:          sw00359530000msuni3400.fits
SUN_POSTN:       139.74d {+09h 18m 58s}  +15.65d {+15d 39' 04"}
SUN_DIST:        162.05 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      357.39d {+23h 49m 34s}   +3.80d {+03d 48' 03"}
MOON_DIST:        28.85 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:       57.92,-39.71 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.76, 11.83 [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:     Sun 09 Aug 09 18:32:20 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     359530,   Seg_Num: 0
GRB_RA:          328.6779d {+21h 54m 42.69s} (J2000),
                 328.8010d {+21h 55m 12.23s} (current),
                 328.0369d {+21h 52m 08.84s} (1950)
GRB_DEC:          -0.0837d {-00d 05' 01.3"} (J2000),
                  -0.0380d {-00d 02' 16.7"} (current),
                  -0.3207d {-00d 19' 14.5"} (1950)
GRB_ERROR:       3.4 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  63218.00 SOD {17:33:38.00} UT,   143.5 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       139.74d {+09h 18m 58s}  +15.65d {+15d 39' 04"}
SUN_DIST:        162.01 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      357.39d {+23h 49m 34s}   +3.80d {+03d 48' 04"}
MOON_DIST:        28.82 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:       57.98,-39.71 [deg] galactic lon,lat of the burst
ECL_COORDS:      330.79, 11.86 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        This is an Update Notice -- the RA,Dec values herein supersede the previous XRT_POS Notice.  
COMMENTS:        TAM values, flux and significance fields are not valid  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
COMMENTS:        This position was enhanced using UVOT field astrometry

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Sun 09 Aug 09 18:32:46 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     359530,   Seg_Num: 0
POINT_RA:        328.654d {+21h 54m 37s} (J2000)
POINT_DEC:        -0.119d {-00d 07' 09"} (J2000)
ROLL:            29.096d
IMG_START_DATE:  15052 TJD;   221 DOY;   09/08/09
IMG_START_TIME:  66470.09 SOD {18:27:50.09} UT,   3395.6 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     271535275
X_OFFSET:        890 [pixels]
Y_OFFSET:        624 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1050
Y_GRB_POS:       784
BINNING_INDEX:   1
IM_URL:          sw00359530000msuni3400.fits
SUN_POSTN:       139.74d {+09h 18m 58s}  +15.65d {+15d 39' 04"}
SUN_DIST:        162.05 [deg]   Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN:      357.39d {+23h 49m 34s}   +3.80d {+03d 48' 10"}
MOON_DIST:        28.86 [deg]
MOON_ILLUM:      87 [%]
GAL_COORDS:       57.92,-39.71 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      330.76, 11.83 [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 Circular #9755
D. Xu, G. Leloudas, D. Malesani, J.P.U. Fynbo (DARK/NBI), P. Jakobsson (Univ. of Iceland), and G. Furesz (CfA/Harvard) report on a larger collaboration:
We observed the field of GRB 090809 (Markwardt et al., GCN 9754) with the Nordic Optical Telescope equipped with ALFOSC. We obtained 3x300 s I-band frames, starting on August 9th, 21:49:10 UT, 4.29889 hr after the burst; and 1x300 s R-band frame, starting 5.29861 hr after the burst.
We confirm the presence of the UVOT source (Markwardt et al., GCN 9754) at coordinates:
```
RA(J2000) = 21:54:43.17
Dec(J2000) = -00:05:01.9
```
which are consistent with the UVOT position. We note that the source is not visible in the archival SDSS frames of this field, thereby proving that it is the optical afterglow of GRB 090809.
The afterglow is detected in each I-band and R-band frame. The preliminary magnitudes are I~19.9 and R~20.3 respectively, against the same reference star, 0899-0602834 in the USNO B1 catalog.
Further photometric observations are underway. We encourage spectroscopic follow-up.
GCN Circular #9756
S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), A. M. Parsons (GSFC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team):
Using the data set from T-60 to T+243 sec from recent telemetry downlinks, we report further analysis of BAT GRB 090809 (trigger #359530) (Markwardt, et al., GCN Circ. 9754). The BAT ground-calculated position is RA, Dec = 328.665, -0.083 deg which is
```
   RA(J2000)  =  21h 54m 39.5s 
   Dec(J2000) = -00d 04' 58.0" 
```
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 43%.
The mask-weighted light curve shows a single, roughly triangularly shaped peak starting at ~T-1 sec, peaking at ~T+3 sec, and ending at ~T+9 sec. T90 (15-350 keV) is 5.4 +- 1.3 sec (estimated error including systematics).
The time-averaged spectrum from T-1.0 to T+6.4 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.34 +- 0.24. The fluence in the 15-150 keV band is 3.4 +- 0.5 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+2.26 sec in the 15-150 keV band is 1.1 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/359530/BA/
GCN Circular #9757
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 5518 s of XRT Photon Counting mode data and 13 UVOT images for GRB 090809, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 328.68012, -0.08366 which is equivalent to:
```
RA (J2000): 21h 54m 43.23s
Dec (J2000): -00d 05' 01.2"
```
with an uncertainty of 1.4 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, arXiv:0812.3662).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #9758
W.B. Landsman (NASA/GSFC) and C. Markwardt (CRESST/GSFC/UMD) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 090809 108s after the BAT trigger (Markwardt et al., GCN Circ. 9754), The tentative UVOT detection reported by Markwardt et al. is confirmed following the downlink of additional data. The UVOT position determined from the white finding chart exposure is
```
RA (J2000)  21:54:43.19   =  328.679938 (deg)
Dec (J2000) -00:05:1.83   =  -0.083842 (deg)
```
with an estimated uncertainty of 0.6 arcsec (radius, 90% confidence, statistical + systematic), consistent with the NOT afterglow position (Xu et al., GCN Circ. 9755).
The initial magnitudes and upper limits are as follows:
```
Filter   T_start(s) Tstop(s) Exp(s)      Mag
white        108    194      84     19.53 +/- 0.14
white       3396   3545     147     21.03 +/- 0.33

v           3552   5181     393     19.87 +/- 0.30
b           4365   5976     367    >21.1  (3 sigma)
u           4162   5796     391    >20.8  (3 sigma)
uvw1        3962   5592     393    >20.7  (3 sigma)
uvm2        3757   5386     393    >20.5  (3 sigma)
uvw2        4776  10964    1082    >21.6  (3 sigma)
```
The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.10 in the direction of the burst (Schlegel et al. 1998). The photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).
GCN Circular #9759
J. Mao, R. Margutti, A. de Ugarte Postigo (INAF-OAB) and C. B. Markwardt (CRESST/GSFC/UMD) report on behalf of the Swift-XRT team:
We have analysed 8.6 ks of XRT data for GRB 090809 (Markwardt et al. GCN Circ. 9754), from 107 s to 23.3 ks after the BAT trigger. The data comprise 59 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN. Circ 9757).
The light curve shows a first flare evidence peaking around 189s, then, it shows a second flare peaking around 4.6ks, these flares make an order of magnitude increase in count-rate, after that, the light curve decays continuously. In general, the underlying light curve can be modelled with a power-law decay with a decay index of alpha=1.02+/-0.02.
A spectrum extracted from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.75 (+/-0.09). The best-fitting absorption column is 2.4 (+/-0.3) x 1021 cm^-2, in excess of the Galactic value of 6.1 x 1020 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.84 (+0.14, -0.13) and a best-fitting absorption column of 1.18 (+0.19, -0.18) x 1021 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 1.08 x 10^-11 (1.24 x 10^-11) erg cm^-2 count^-1.
If the light curve continues to decay with a power-law decay index of 1.0, the count rate at T+24 hours will be 0.007 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.9 x 10^-13 (3.4 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00359530.
This circular is an official product of the Swift-XRT team.
GCN Circular #9761
D. Malesani, J.P.U. Fynbo (DARK/NBI), L. Christensen (ESO), A. de Ugarte Postigo (OAB-INAF), B. Milvang-Jensen (DARK/NBI), S. Covino (OAB-INAF) report on behalf of a larger collaboration
We have observed the afterglow of GRB 090809 (Markwardt et al. GCNC 9754) using the X-shooter spectrograph mounted at the Kueyen telescope of ESO's VLT (Paranal Observatory, Chile) during its science verification phase. The spectrum, consisting of a combined exposure of 4x1800s, was started at 03:40 UT on August 09 (10.15 hrs after the burst). It was obtained with an initial seeing of 0.9" and an airmass of 1.2, when the afterglow had a magnitude of R~21. The spectrum covers the complete range from 3000 to 25000 Angstroms. In a preliminary analysis we identify the Lyman break, Lyman-alpha, SiII, OI, SiI*, SiIV, CIV, FeII, AlII, AlIII and MgII at a common redshift of 2.737 +/- 0.002 (pending final wavelength calibration), which we identify as the redshift of the GRB.
We thank the Paranal staff for excellent support, in particular Elena Mason and Claudia Cid.
GCN Circular #9762
K. Wiersema (Leicester), D. Malesani (DARK/NBI), A. Levan, D. Steeghs, L. van Spaandonk (Warwick) report on behalf of a larger collaboration:
We observed the field of GRB 090809 (Markwardt et al. GCN 9754) with the William Herschel Telescope using the ACAM instrument. Observations consisted of 4 x 300 second exposures with a sloan i filter, starting on August 9, 23:41 UT (6.16 hrs after burst). We clearly detect the afterglow (Markwardt et al. GCN 9754, Xu et al. GCN 9755) with i = 20.48 +/- 0.03 (calibrated using SDSS stars).
GCN Circular #9765
Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on behalf of a larger collaboration:
"We used the Very Large Array to observe the field of view toward GRB 090809 (GCN 9754) at a frequency of 8.46 GHz on 2009 Aug. 11.37 UT. The GRB radio afterglow is undetected. The peak flux at the NOT optical afterglow position (GCN 9755) is 8+/-39 uJy.
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN Circular #9766
D. Xu, G. Leloudas, J. P. U. Fynbo, D. Malesani (DARK/NBI), P. Jakobsson (Univ. Iceland), and and G. Furesz (CfA/Harvard) report on behalf of a larger collaboration:
We continued to observe the field of GRB 090809 (Markwardt et al., GCN 9754; Xu et al., GCN 9755; Landsman et al., GCN 9758) with the Nordic Optical Telescope equipped with ALFOSC. We obtained 4x300 s i-band frames staring on August 10th, 22:25:35 UT, 28.9 hr after the burst.
The optical afterglow is still detected in the stacked frame. The magnitude is i=22.3+/-0.1 against several reference stars of the USNO B1 catalog in the field. The improved magnitude in our previous observation is i=20.20+/-0.04, being consistent with the measurement in Wiersema et al. (GCN 9762). Therefore, the optical afterglow is decaying with a power-law slope of \alpha=1.0, similar to the general decaying of the X-ray afterglow (Mao et al., GCN 9759).
We note that the rest-frame T90 (Barthelmy et al., GCN 9756) is less than 2 s for this burst at z=2.737 (Malesani et al., GCN9761). But the early energetic X-ray flares tend to make this burst more consistent with the class of the conventional long bursts.

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Jochen Greiner, last update: 11-Aug-2009 [Disclaimer]