Gamma-ray Burst 090123

(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 23 Jan 09 07:52:45 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     340895,   Seg_Num: 0
GRB_RA:            6.775d {+00h 27m 06s} (J2000),
                   6.889d {+00h 27m 33s} (current),
                   6.148d {+00h 24m 36s} (1950)
GRB_DEC:         -23.514d {-23d 30' 49"} (J2000),
                 -23.464d {-23d 27' 49"} (current),
                 -23.791d {-23d 47' 25"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4355 [cnts]    Image_Peak=155 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   146     E_range: 25-100 keV
BKG_INTEN:       29928 [cnts]
BKG_TIME:        28299.56 SOD {07:51:39.56} UT
BKG_DUR:         8 [sec]
GRB_DATE:        14854 TJD;    23 DOY;   09/01/23
GRB_TIME:        28316.32 SOD {07:51:56.32} UT
GRB_PHI:         -158.19 [deg]
GRB_THETA:        45.77 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     7.93 [sigma]
IMAGE_SIGNIF:    7.15 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +2  -1  +0  +0 -55  +0 
SUN_POSTN:       305.75d {+20h 22m 59s}  -19.38d {-19d 23' 02"}
SUN_DIST:         56.65 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      270.82d {+18h 03m 18s}  -26.78d {-26d 46' 54"}
MOON_DIST:        84.67 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       64.91,-83.42 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      356.26,-24.15 [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 = 18.26,13.66 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 07:54:16 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     340895,   Seg_Num: 0
GRB_RA:            6.7863d {+00h 27m 08.7s} (J2000),
                   6.8998d {+00h 27m 35.9s} (current),
                   6.1595d {+00h 24m 38.2s} (1950)
GRB_DEC:         -23.5007d {-23d 30' 02.5"} (J2000),
                 -23.4506d {-23d 27' 02.1"} (current),
                 -23.7773d {-23d 46' 38.3"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       73 [cnts]
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28416.22 SOD {07:53:36.22} UT,   99.9 [sec] since BAT Trigger Time
CENTROID_X:      279.43,  raw= 279  [pixels]
CENTROID_Y:      304.51,  raw= 305  [pixels]
ROLL:            261.60 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   15.35
GRB_POS_XRT_Z:   -53.88
IMAGE_URL:       sw00340895000msxps_rw.img
SUN_POSTN:       305.75d {+20h 23m 00s}  -19.38d {-19d 23' 01"}
SUN_DIST:         56.66 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      270.84d {+18h 03m 21s}  -26.78d {-26d 46' 50"}
MOON_DIST:        84.67 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.06,-83.42 [deg] galactic lon,lat of the burst
ECL_COORDS:      356.28,-24.14 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 07:54:06 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     340895,   Seg_Num: 0
GRB_RA:            6.7863d {+00h 27m 08.71s} (J2000),
                   6.8998d {+00h 27m 35.95s} (current),
                   6.1595d {+00h 24m 38.28s} (1950)
GRB_DEC:         -23.5007d {-23d 30' 02.5"} (J2000),
                 -23.4506d {-23d 27' 02.1"} (current),
                 -23.7773d {-23d 46' 38.3"} (1950)
GRB_ERROR:       5.1 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       2.05e-09 [erg/cm2/sec]
GRB_SIGNIF:      8.54 [sigma]
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28416.22 SOD {07:53:36.22} UT,   99.9 [sec] since BAT Trigger Time
TAM[0-3]:        327.67 237.25 261.53 243.32
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       305.75d {+20h 23m 00s}  -19.38d {-19d 23' 01"}
SUN_DIST:         56.66 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      270.84d {+18h 03m 21s}  -26.78d {-26d 46' 51"}
MOON_DIST:        84.68 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.06,-83.42 [deg] galactic lon,lat of the burst
ECL_COORDS:      356.28,-24.14 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 1.00 arcmin from the BAT position.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 07:54:22 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     340895,   Seg_Num: 0
GRB_RA:            6.7863d {+00h 27m 08.7s} (J2000),
                   6.8998d {+00h 27m 35.9s} (current),
                   6.1595d {+00h 24m 38.2s} (1950)
GRB_DEC:         -23.5007d {-23d 30' 02.5"} (J2000),
                 -23.4506d {-23d 27' 02.1"} (current),
                 -23.7773d {-23d 46' 38.3"} (1950)
GRB_ERROR:       5.0 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       73 [cnts]
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28416.22 SOD {07:53:36.22} UT,   99.9 [sec] since BAT Trigger Time
CENTROID_X:      279.43,  raw= 279  [pixels]
CENTROID_Y:      304.51,  raw= 305  [pixels]
ROLL:            261.60 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   15.35
GRB_POS_XRT_Z:   -53.88
IMAGE_URL:       sw00340895000msxps_rw.img
SUN_POSTN:       305.75d {+20h 23m 00s}  -19.38d {-19d 23' 01"}
SUN_DIST:         56.66 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      270.84d {+18h 03m 21s}  -26.78d {-26d 46' 50"}
MOON_DIST:        84.67 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.06,-83.42 [deg] galactic lon,lat of the burst
ECL_COORDS:      356.28,-24.14 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 07:55:29 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     340895,   Seg_Num: 0
GRB_RA:            6.775d {+00h 27m 06s} (J2000),
                   6.889d {+00h 27m 33s} (current),
                   6.148d {+00h 24m 36s} (1950)
GRB_DEC:         -23.514d {-23d 30' 49"} (J2000),
                 -23.464d {-23d 27' 49"} (current),
                 -23.791d {-23d 47' 25"} (1950)
GRB_DATE:        14854 TJD;    23 DOY;   09/01/23
GRB_TIME:        28316.32 SOD {07:51:56.32} UT
TRIGGER_INDEX:   146
GRB_PHI:         -158.19 [deg]
GRB_THETA:        45.77 [deg]
DELTA_TIME:      -75.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     7.93 [sigma]
IMAGE_SIGNIF:    7.15 [sigma]
LC_URL:          sw00340895000msb.lc
SUN_POSTN:       305.75d {+20h 23m 00s}  -19.38d {-19d 23' 00"}
SUN_DIST:         56.64 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      270.85d {+18h 03m 24s}  -26.78d {-26d 46' 48"}
MOON_DIST:        84.65 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       64.91,-83.42 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      356.26,-24.15 [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 = 18.26,13.66 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 07:57:56 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     340895,   Seg_Num: 0
POINT_RA:          6.801d {+00h 27m 12s} (J2000)
POINT_DEC:       -23.494d {-23d 29' 39"} (J2000)
POINT_ROLL:      261.599d
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28423.52 SOD {07:53:43.52} UT,   107.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.303
N_STARS:         46
X_OFFSET:        584 [pixels]
Y_OFFSET:        360 [pixels]
X_MAX:           1543 [pixels]
Y_MAX:           1319 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00340895000msufc0107.fits
SUN_POSTN:       305.75d {+20h 23m 00s}  -19.38d {-19d 23' 00"}
SUN_DIST:         56.67 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      270.87d {+18h 03m 29s}  -26.78d {-26d 46' 42"}
MOON_DIST:        84.66 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.17,-83.43 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      356.30,-24.14 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 07:58:13 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     340895,   Seg_Num: 0
POINT_RA:          6.801d {+00h 27m 12s} (J2000)
POINT_DEC:       -23.494d {-23d 29' 39"} (J2000)
POINT_ROLL:      261.599d
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28423.52 SOD {07:53:43.52} UT,   107.2 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.303
N_STARS:         46
X_OFFSET:        584 [pixels]
Y_OFFSET:        360 [pixels]
X_MAX:           1543 [pixels]
Y_MAX:           1319 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw00340895000msufc0107.fits
SUN_POSTN:       305.75d {+20h 23m 00s}  -19.38d {-19d 22' 59"}
SUN_DIST:         56.67 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      270.87d {+18h 03m 30s}  -26.78d {-26d 46' 41"}
MOON_DIST:        84.66 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.17,-83.43 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      356.30,-24.14 [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 23 Jan 09 08:00:34 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     340895,   Seg_Num: 0
POINT_RA:          6.801d {+00h 27m 12s} (J2000)
POINT_DEC:       -23.494d {-23d 29' 39"} (J2000)
ROLL:            261.599d
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28423.52 SOD {07:53:43.52} UT,   107.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     254390027
X_OFFSET:        868 [pixels]
Y_OFFSET:        789 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1028
Y_GRB_POS:       949
BINNING_INDEX:   1
IM_URL:          sw00340895000msuni0107.fits
SUN_POSTN:       305.75d {+20h 23m 01s}  -19.38d {-19d 22' 57"}
SUN_DIST:         56.67 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      270.90d {+18h 03m 35s}  -26.78d {-26d 46' 36"}
MOON_DIST:        84.64 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.17,-83.43 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      356.30,-24.14 [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).  
COMMENTS:        This notice was forced out after watchdog timer expiring -- most likely due to missing packet(s);  
COMMENTS:        as a consequence some of the fields may be incoorect (eg TRIGGER_NUM,RA,DEC).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 08:01:02 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     340895,   Seg_Num: 0
POINT_RA:          6.801d {+00h 27m 12s} (J2000)
POINT_DEC:       -23.494d {-23d 29' 39"} (J2000)
ROLL:            261.599d
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28423.52 SOD {07:53:43.52} UT,   107.2 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     254390027
X_OFFSET:        868 [pixels]
Y_OFFSET:        789 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1028
Y_GRB_POS:       949
BINNING_INDEX:   1
IM_URL:          sw00340895000msuni0107.fits
SUN_POSTN:       305.75d {+20h 23m 01s}  -19.38d {-19d 22' 57"}
SUN_DIST:         56.67 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      270.90d {+18h 03m 36s}  -26.78d {-26d 46' 35"}
MOON_DIST:        84.64 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.17,-83.43 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      356.30,-24.14 [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_sources_image.fits.gz file does not exist; skipping the attachment.  
COMMENTS:        This notice was forced out after watchdog timer expiring -- most likely due to missing packet(s);  
COMMENTS:        as a consequence some of the fields may be incoorect (eg TRIGGER_NUM,RA,DEC).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 08:07:22 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     340895,   Seg_Num: 0
GRB_RA:            6.7864d {+00h 27m 08.73s} (J2000),
                   6.8999d {+00h 27m 35.97s} (current),
                   6.1596d {+00h 24m 38.30s} (1950)
GRB_DEC:         -23.5011d {-23d 30' 03.9"} (J2000),
                 -23.4510d {-23d 27' 03.6"} (current),
                 -23.7777d {-23d 46' 39.8"} (1950)
GRB_ERROR:       0.8 [arcsec radius, statistical only]
GRB_MAG:         17.70 +/- 0.14 [mag]
FILTER:          10, White
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28425.00 SOD {07:53:45.00} UT,   108.7 [sec] since BAT Trigger Time
SUN_POSTN:       305.76d {+20h 23m 02s}  -19.38d {-19d 22' 53"}
SUN_DIST:         56.65 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      270.96d {+18h 03m 50s}  -26.77d {-26d 46' 20"}
MOON_DIST:        84.58 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.06,-83.42 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      356.28,-24.14 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The UVOT position is 1.1 arcsec from the XRT position.

GCN Circular #8842
D. Grupe (PSU), P. A. Evans (U Leicester), C. Gronwall (PSU), C. Guidorzi (U Ferrara), S. T. Holland (CRESST/USRA/GSFC), J. L. Racusin (PSU), M. Stamatikos (NASA/ORAU) and L. Vetere (PSU) report on behalf of the Swift Team:
At 07:51:56 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090123 (trigger=340895). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 6.775, -23.514 which is
```
   RA(J2000) = 00h 27m 06s
   Dec(J2000) = -23d 30' 49"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 30 sec, beginning at about T-10 sec. The peak count rate was ~1000 counts/sec (15-350 keV), at ~2 sec after the trigger.
The XRT began observing the field at 07:53:36.2 UT, 99.9 seconds after the BAT trigger. XRT found a bright, uncatalogued X-ray source located at RA, Dec 6.7863, -23.5007 which is equivalent to:
```
   RA(J2000)  = 00h 27m 08.71s
   Dec(J2000) = -23d 30' 02.5"
```
with an uncertainty of 5.1 arcseconds (radius, 90% containment). This location is 60 arcseconds from the BAT onboard position, within the BAT error circle. No event data are yet available to determine the column density using X-ray spectroscopy.
UVOT took a finding chart exposure of 150 seconds with the White filter starting 107 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =	00:27:08.74 =  6.78641
  DEC(J2000) = -23:30:03.9  = -23.50108
```
with a 90%-confidence error radius of about 0.75 arc sec. This position is 1.4 arc sec. from the center of the XRT error circle. The estimated magnitude is 17.71 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.02.
Burst Advocate for this burst is D. Grupe (grupe AT astro.psu.edu). 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:     Fri 23 Jan 09 08:18:45 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     340895,   Seg_Num: 0
POINT_RA:          6.801d {+00h 27m 12s} (J2000)
POINT_DEC:       -23.493d {-23d 29' 34"} (J2000)
POINT_ROLL:      261.598d
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28635.87 SOD {07:57:15.87} UT,   319.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.270
N_STARS:         37
X_OFFSET:        548 [pixels]
Y_OFFSET:        469 [pixels]
X_MAX:           1507 [pixels]
Y_MAX:           1428 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    4
SL_URL:          sw00340895000msufc0319.fits
SUN_POSTN:       305.77d {+20h 23m 04s}  -19.38d {-19d 22' 47"}
SUN_DIST:         56.66 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      271.06d {+18h 04m 15s}  -26.77d {-26d 45' 54"}
MOON_DIST:        84.51 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.18,-83.43 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      356.30,-24.14 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 08:19:14 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     340895,   Seg_Num: 0
POINT_RA:          6.801d {+00h 27m 12s} (J2000)
POINT_DEC:       -23.493d {-23d 29' 34"} (J2000)
POINT_ROLL:      261.598d
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28635.87 SOD {07:57:15.87} UT,   319.5 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.270
N_STARS:         37
X_OFFSET:        548 [pixels]
Y_OFFSET:        469 [pixels]
X_MAX:           1507 [pixels]
Y_MAX:           1428 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    4
SL_URL:          sw00340895000msufc0319.fits
SUN_POSTN:       305.77d {+20h 23m 04s}  -19.38d {-19d 22' 46"}
SUN_DIST:         56.66 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      271.07d {+18h 04m 16s}  -26.76d {-26d 45' 53"}
MOON_DIST:        84.51 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.18,-83.43 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      356.30,-24.14 [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 23 Jan 09 08:20:07 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     340895,   Seg_Num: 0
POINT_RA:          6.801d {+00h 27m 12s} (J2000)
POINT_DEC:       -23.493d {-23d 29' 34"} (J2000)
ROLL:            261.598d
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28635.87 SOD {07:57:15.87} UT,   319.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     254390240
X_OFFSET:        868 [pixels]
Y_OFFSET:        789 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1028
Y_GRB_POS:       949
BINNING_INDEX:   1
IM_URL:          sw00340895000msuni0319.fits
SUN_POSTN:       305.77d {+20h 23m 04s}  -19.38d {-19d 22' 46"}
SUN_DIST:         56.66 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      271.08d {+18h 04m 18s}  -26.76d {-26d 45' 51"}
MOON_DIST:        84.50 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.18,-83.43 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      356.30,-24.14 [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 23 Jan 09 08:20:23 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     340895,   Seg_Num: 0
POINT_RA:          6.801d {+00h 27m 12s} (J2000)
POINT_DEC:       -23.493d {-23d 29' 34"} (J2000)
ROLL:            261.598d
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28635.87 SOD {07:57:15.87} UT,   319.5 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     254390240
X_OFFSET:        868 [pixels]
Y_OFFSET:        789 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1028
Y_GRB_POS:       949
BINNING_INDEX:   1
IM_URL:          sw00340895000msuni0319.fits
SUN_POSTN:       305.77d {+20h 23m 04s}  -19.38d {-19d 22' 46"}
SUN_DIST:         56.66 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      271.08d {+18h 04m 19s}  -26.76d {-26d 45' 50"}
MOON_DIST:        84.50 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.18,-83.43 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      356.30,-24.14 [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_sources_image.fits.gz file does not exist; skipping the attachment.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 08:21:24 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     340895,   Seg_Num: 0
GRB_RA:            6.7864d {+00h 27m 08.73s} (J2000),
                   6.8999d {+00h 27m 35.97s} (current),
                   6.1596d {+00h 24m 38.30s} (1950)
GRB_DEC:         -23.5016d {-23d 30' 05.7"} (J2000),
                 -23.4515d {-23d 27' 05.4"} (current),
                 -23.7782d {-23d 46' 41.6"} (1950)
GRB_ERROR:       3.8 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  28758.00 SOD {07:59:18.00} UT,   441.7 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       305.77d {+20h 23m 04s}  -19.38d {-19d 22' 45"}
SUN_DIST:         56.64 [deg]   Sun_angle= -4.1 [hr] (East of Sun)
MOON_POSTN:      271.09d {+18h 04m 21s}  -26.76d {-26d 45' 48"}
MOON_DIST:        84.48 [deg]
MOON_ILLUM:      8 [%]
GAL_COORDS:       65.05,-83.42 [deg] galactic lon,lat of the burst
ECL_COORDS:      356.28,-24.14 [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.

GCN Circular #8843
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team.
Using 1885 s of XRT Photon Counting mode data and 1 UVOT images for GRB090123, 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 = 6.78599, -23.50156 which is equivalent to:
```
RA (J2000): 00h 27m 8.64s
Dec (J2000): -23d 30' 05.6"
```
with an uncertainty of 1.7 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 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method.
This circular was automatically generated, and is an official product of the Swift-XRT team.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 23 Jan 09 14:47:19 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     340919,   Seg_Num: 0
GRB_RA:          170.2407d {+11h 20m 57.7s} (J2000),
                 170.3409d {+11h 21m 21.8s} (current),
                 169.6906d {+11h 18m 45.7s} (1950)
GRB_DEC:         -61.9168d {-61d 55' 00.4"} (J2000),
                 -61.9665d {-61d 57' 59.5"} (current),
                 -61.6427d {-61d 38' 33.5"} (1950)
GRB_ERROR:       5.4 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       28 [cnts]
IMG_START_DATE:  14854 TJD;    23 DOY;   09/01/23
IMG_START_TIME:  53186.96 SOD {14:46:26.96} UT,   2447.4 [sec] since BAT Trigger Time
CENTROID_X:      304.82,  raw= 305  [pixels]
CENTROID_Y:      354.86,  raw= 355  [pixels]
ROLL:            138.90 [deg]
GAIN:            1
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   134.04
GRB_POS_XRT_Z:   5.95
IMAGE_URL:       sw00340919000msxps_rw.img
SUN_POSTN:       306.05d {+20h 24m 12s}  -19.32d {-19d 18' 56"}
SUN_DIST:         91.46 [deg]   Sun_angle= 9.0 [hr] (West of Sun)
MOON_POSTN:      274.62d {+18h 18m 30s}  -26.47d {-26d 28' 06"}
MOON_DIST:        73.16 [deg]
MOON_ILLUM:      7 [%]
GAL_COORDS:      292.50, -0.89 [deg] galactic lon,lat of the burst
ECL_COORDS:      210.91,-57.27 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.

GCN Circular #8844
T. N. Ukwatta (GWU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), D. Grupe (PSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from recent telemetry downlinks, we report further analysis of BAT GRB 090123 (trigger #340895) (Grupe, et al., GCN Circ. 8842). The BAT ground-calculated position is RA, Dec = 6.794, -23.503 deg, which is
```
   RA(J2000)  =  00h 27m 10.5s 
   Dec(J2000) = -23d 30' 12.6" 
```
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 36%.
The mask-weighted light curve shows multiple overlapping peaks starting at ~T-48 sec, with the max peak at ~T+3 sec, and ending at ~T+120 sec. T90 (15-350 keV) is 131 +- 23 sec (estimated error including systematics).
The time-averaged spectrum from T-49.6 to T+117.9 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.74 +- 0.12. The fluence in the 15-150 keV band is 2.9 +- 0.2 x 10^-6 erg/cm2. The 1-sec peak photon flux measured from T+0.08 sec in the 15-150 keV band is 1.7 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/340895/BA/
GCN Circular #8846
F.E. Marshall (NASA/GSFC) and D. Grupe (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT observed the field of GRB 090123 starting 107 s after the BAT trigger (Grupe et al., GCN Circ. 8842). We detect the optical afterglow (Grupe et al.) in the white, v, b, u, uvw1, uvm2, and uvw2 filters at the position:
```
  RA(J2000)  =  00:27:08.73 =   6.78639
  DEC(J2000) = -23:30:04.1  = -23.50113
```
with an estimated uncertainty of 0.5 arc sec. (radius, 90% confidence). There is a broad peak in the light curve ~600 sec. after the trigger. The 3.4-sigma detection in the uvw2 filter indicates that the redshift is less than ~1.4.
The magnitudes in the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) in the first finding chart (FC) exposure and subsequent exposures are:
```
Filter          T_start(s)   T_stop(s)      Exp(s)       Mag 

white (FC)         107          257          147         17.8 +/- 0.1
v                  649          669           20         15.4 +/- 0.1
b                  575          595           20         15.8 +/- 0.1
u                  320          570          250         16.4 +/- 0.1
uvw1               698          718           20         17.3 +/- 0.23
uvm2              1251         8112          294         19.6 +/- 0.25
uvw2              1547         7843          413         20.5 +/- 0.29
```
The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #8847
D. Grupe (PSU) reports on behalf of the Swift-XRT team:
We have analyzed 7.7 ks of XRT data for GRB090123 (Grupe et al. GCN Circ. 8842), beginning 106 s after the BAT trigger. The data comprise 334 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 8843).
The light curve can be modeled with an initial power-law decay with an index of alpha=1.78 (+0.06, -0.08), followed by a break at T+1530 (+720,-220) s to an alpha of 1.20 (+0.08, -0.10).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.65+/-0.05 with an absorption column fixed to the Galactic value of 1.79 x 1020 cm-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 1.81+/-0.08 and an absorption column density also consistent with the Galactic value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.2 x 10-11 (4.5 x 10-11) erg cm-2 count-1.
If the light curve continues to decay with a power-law decay index of 1.20, the count rate at T+24 hours will be 0.0031 counts/s, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.3 x 10-13 (1.4 x 10-13) erg cm-2 s-1.
GCN Circular #8849
A. Rossi (Tautenburg Obs.) and J. Greiner (MPE Garching) report on behalf of the GROND team:
GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m ESO/MPI telescope at La Silla Observatory (Chile) imaged the field of GRB 090123 (Swift trigger 340895, Grupe et al. 2009, GCN #8842) simultaneously in g'r'i'z'JHK. Observation started on 2009-01-24 at 01:22 UTC, about 17 hours after the burst. The total exposure time was 25 minutes, the average seeing 1.3 at airmass 2.5.
We detect the afterglow at the position reported by SWIFT UVOT (Marshall et al 2009, GCN #8846) in g'r'i'z', but not in JHK. We estimate the following observed magnitudes and upper limits (all in AB system):
```
g' = 22.77 +- 0.05
r' = 22.45 +- 0.05
i' = 21.95 +- 0.08
z' = 22.09 +- 0.12
J > 21.5
H > 21.0
K > 20.5
```
calibrated against GROND zeropoints and 2MASS field stars.
GCN Report 194.1
GCN_Report 194.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_194_1.pdf by D. Grupe at PSU titled: "Final Swift Observations of GRB 090123"

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Jochen Greiner, last update: 02-Feb-2009 [Disclaimer]