Gamma-ray Burst 251112A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

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Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 12 Nov 25 21:29:27 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1413695,   Seg_Num: 0
GRB_RA:          274.019d {+18h 16m 05s} (J2000),
                 274.286d {+18h 17m 09s} (current),
                 273.503d {+18h 14m 01s} (1950)
GRB_DEC:         +24.226d {+24d 13' 32"} (J2000),
                 +24.236d {+24d 14' 09"} (current),
                 +24.207d {+24d 12' 26"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       5237 [cnts]    Image_Peak=213 [image_cnts]
TRIGGER_DUR:     2.048 [sec] 
TRIGGER_INDEX:   473     E_range: 25-100 keV
BKG_INTEN:       51788 [cnts]
BKG_TIME:        77299.32 SOD {21:28:19.32} UT
BKG_DUR:         24 [sec]
GRB_DATE:        20991 TJD;   316 DOY;   25/11/12
GRB_TIME:        77335.86 SOD {21:28:55.86} UT
GRB_PHI:         137.62 [deg]
GRB_THETA:        10.62 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     11.74 [sigma]
IMAGE_SIGNIF:    7.94 [sigma]
MERIT_PARAMS:     +1  +0  +0  +1  +2  -2  +0  +0 -47  +0 
SUN_POSTN:       228.31d {+15h 13m 16s}  -17.94d {-17d 56' 16"}
SUN_DIST:         61.54 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.50d {+10h 06m 00s}  +13.42d {+13d 25' 06"}
MOON_DIST:       112.65 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.42, 18.17 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      275.44, 47.59 [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 = 217.04,-8.50 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 12 Nov 25 21:30:35 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.012d {+18h 16m 03s} (J2000)
POINT_DEC:       +24.221d {+24d 13' 16"} (J2000)
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  77422.79 SOD {21:30:22.79} UT,   86.9 [sec] since BAT Trigger Time
COUNTS:          45    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        4    Max_iter_allowed= 4
ERROR_CODE:      2
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        Algorithm did not converge; too many iterations.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 12 Nov 25 21:34:20 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.011d {+18h 16m 03s} (J2000)
POINT_DEC:       +24.221d {+24d 13' 15"} (J2000)
POINT_ROLL:      230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  77426.97 SOD {21:30:26.97} UT,   91.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.979
N_STARS:         136
X_OFFSET:        413 [pixels]
Y_OFFSET:        572 [pixels]
X_MAX:           1372 [pixels]
Y_MAX:           1531 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw01413695000msufc0091.fits
SUN_POSTN:       228.32d {+15h 13m 16s}  -17.94d {-17d 56' 19"}
SUN_DIST:         61.53 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.54d {+10h 06m 10s}  +13.40d {+13d 23' 58"}
MOON_DIST:       112.62 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 12 Nov 25 21:34:36 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.011d {+18h 16m 03s} (J2000)
POINT_DEC:       +24.221d {+24d 13' 15"} (J2000)
POINT_ROLL:      230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  77426.97 SOD {21:30:26.97} UT,   91.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        4.979
N_STARS:         136
X_OFFSET:        413 [pixels]
Y_OFFSET:        572 [pixels]
X_MAX:           1372 [pixels]
Y_MAX:           1531 [pixels]
DET_THRESH:      19
PHOTO_THRESH:    11
SL_URL:          sw01413695000msufc0091.fits
SUN_POSTN:       228.32d {+15h 13m 16s}  -17.94d {-17d 56' 19"}
SUN_DIST:         61.53 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.54d {+10h 06m 10s}  +13.40d {+13d 23' 55"}
MOON_DIST:       112.62 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.58 [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:     Wed 12 Nov 25 21:35:53 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.011d {+18h 16m 03s} (J2000)
POINT_DEC:       +24.221d {+24d 13' 15"} (J2000)
ROLL:            230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  77426.97 SOD {21:30:26.97} UT,   91.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     784675863
X_OFFSET:        732 [pixels]
Y_OFFSET:        891 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       892
Y_GRB_POS:       1051
BINNING_INDEX:   1
IM_URL:          sw01413695000msuni0128.fits
SUN_POSTN:       228.32d {+15h 13m 17s}  -17.94d {-17d 56' 20"}
SUN_DIST:         61.53 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.55d {+10h 06m 13s}  +13.39d {+13d 23' 37"}
MOON_DIST:       112.61 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Processed Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).  
COMMENTS:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 12 Nov 25 21:35:46 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.011d {+18h 16m 03s} (J2000)
POINT_DEC:       +24.221d {+24d 13' 15"} (J2000)
ROLL:            230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  77426.97 SOD {21:30:26.97} UT,   91.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     784675863
X_OFFSET:        732 [pixels]
Y_OFFSET:        891 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       892
Y_GRB_POS:       1051
BINNING_INDEX:   1
IM_URL:          sw01413695000msuni0128.fits
SUN_POSTN:       228.32d {+15h 13m 17s}  -17.94d {-17d 56' 20"}
SUN_DIST:         61.53 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.55d {+10h 06m 13s}  +13.39d {+13d 23' 38"}
MOON_DIST:       112.61 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.17 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.58 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 12 Nov 25 21:55:51 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.010d {+18h 16m 02s} (J2000)
POINT_DEC:       +24.222d {+24d 13' 18"} (J2000)
POINT_ROLL:      230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  77639.25 SOD {21:33:59.25} UT,   303.4 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.530
N_STARS:         190
X_OFFSET:        173 [pixels]
Y_OFFSET:        332 [pixels]
X_MAX:           1612 [pixels]
Y_MAX:           1771 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01413695000msufc0303.fits
SUN_POSTN:       228.33d {+15h 13m 20s}  -17.94d {-17d 56' 34"}
SUN_DIST:         61.52 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.72d {+10h 06m 53s}  +13.32d {+13d 18' 60"}
MOON_DIST:       112.52 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.18 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 12 Nov 25 21:56:07 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.010d {+18h 16m 02s} (J2000)
POINT_DEC:       +24.222d {+24d 13' 18"} (J2000)
POINT_ROLL:      230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  77639.25 SOD {21:33:59.25} UT,   303.4 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        1.530
N_STARS:         190
X_OFFSET:        173 [pixels]
Y_OFFSET:        332 [pixels]
X_MAX:           1612 [pixels]
Y_MAX:           1771 [pixels]
DET_THRESH:      10
PHOTO_THRESH:    5
SL_URL:          sw01413695000msufc0303.fits
SUN_POSTN:       228.33d {+15h 13m 20s}  -17.94d {-17d 56' 34"}
SUN_DIST:         61.52 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.72d {+10h 06m 53s}  +13.32d {+13d 18' 56"}
MOON_DIST:       112.52 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.18 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.59 [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:     Wed 12 Nov 25 21:57:24 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.010d {+18h 16m 02s} (J2000)
POINT_DEC:       +24.222d {+24d 13' 18"} (J2000)
ROLL:            230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  77639.25 SOD {21:33:59.25} UT,   303.4 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     784676075
X_OFFSET:        732 [pixels]
Y_OFFSET:        891 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       892
Y_GRB_POS:       1051
BINNING_INDEX:   1
IM_URL:          sw01413695000msuni0340.fits
SUN_POSTN:       228.33d {+15h 13m 20s}  -17.94d {-17d 56' 35"}
SUN_DIST:         61.52 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.73d {+10h 06m 56s}  +13.31d {+13d 18' 38"}
MOON_DIST:       112.51 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.18 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.59 [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:     Wed 12 Nov 25 21:57:17 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.010d {+18h 16m 02s} (J2000)
POINT_DEC:       +24.222d {+24d 13' 18"} (J2000)
ROLL:            230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  77639.25 SOD {21:33:59.25} UT,   303.4 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     784676075
X_OFFSET:        732 [pixels]
Y_OFFSET:        891 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       892
Y_GRB_POS:       1051
BINNING_INDEX:   1
IM_URL:          sw01413695000msuni0340.fits
SUN_POSTN:       228.33d {+15h 13m 20s}  -17.94d {-17d 56' 35"}
SUN_DIST:         61.52 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.73d {+10h 06m 56s}  +13.31d {+13d 18' 40"}
MOON_DIST:       112.51 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.18 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.59 [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:     Wed 12 Nov 25 22:01:08 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.010d {+18h 16m 02s} (J2000)
POINT_DEC:       +24.222d {+24d 13' 19"} (J2000)
POINT_ROLL:      230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  78192.22 SOD {21:43:12.22} UT,   856.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.688
N_STARS:         190
X_OFFSET:        173 [pixels]
Y_OFFSET:        332 [pixels]
X_MAX:           1612 [pixels]
Y_MAX:           1771 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw01413695000msufc0856.fits
SUN_POSTN:       228.34d {+15h 13m 21s}  -17.94d {-17d 56' 37"}
SUN_DIST:         61.52 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.76d {+10h 07m 03s}  +13.30d {+13d 17' 46"}
MOON_DIST:       112.49 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.18 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.59 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Wed 12 Nov 25 22:01:17 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.010d {+18h 16m 02s} (J2000)
POINT_DEC:       +24.222d {+24d 13' 19"} (J2000)
POINT_ROLL:      230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  78192.22 SOD {21:43:12.22} UT,   856.4 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.688
N_STARS:         190
X_OFFSET:        173 [pixels]
Y_OFFSET:        332 [pixels]
X_MAX:           1612 [pixels]
Y_MAX:           1771 [pixels]
DET_THRESH:      14
PHOTO_THRESH:    7
SL_URL:          sw01413695000msufc0856.fits
SUN_POSTN:       228.34d {+15h 13m 21s}  -17.94d {-17d 56' 37"}
SUN_DIST:         61.52 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.77d {+10h 07m 04s}  +13.30d {+13d 17' 44"}
MOON_DIST:       112.49 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.18 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.59 [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:     Wed 12 Nov 25 22:02:47 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.010d {+18h 16m 02s} (J2000)
POINT_DEC:       +24.222d {+24d 13' 19"} (J2000)
ROLL:            230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  78192.22 SOD {21:43:12.22} UT,   856.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     784676628
X_OFFSET:        732 [pixels]
Y_OFFSET:        891 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       892
Y_GRB_POS:       1051
BINNING_INDEX:   1
IM_URL:          sw01413695000msuni0893.fits
SUN_POSTN:       228.34d {+15h 13m 21s}  -17.94d {-17d 56' 38"}
SUN_DIST:         61.52 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.78d {+10h 07m 07s}  +13.29d {+13d 17' 23"}
MOON_DIST:       112.49 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.18 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.59 [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:     Wed 12 Nov 25 22:02:40 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1413695,   Seg_Num: 0
POINT_RA:        274.010d {+18h 16m 02s} (J2000)
POINT_DEC:       +24.222d {+24d 13' 19"} (J2000)
ROLL:            230.890d
IMG_START_DATE:  20991 TJD;   316 DOY;   25/11/12
IMG_START_TIME:  78192.22 SOD {21:43:12.22} UT,   856.4 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     784676628
X_OFFSET:        732 [pixels]
Y_OFFSET:        891 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       892
Y_GRB_POS:       1051
BINNING_INDEX:   1
IM_URL:          sw01413695000msuni0893.fits
SUN_POSTN:       228.34d {+15h 13m 21s}  -17.94d {-17d 56' 38"}
SUN_DIST:         61.52 [deg]   Sun_angle= -3.1 [hr] (East of Sun)
MOON_POSTN:      151.78d {+10h 07m 06s}  +13.29d {+13d 17' 25"}
MOON_DIST:       112.49 [deg]
MOON_ILLUM:      43 [%]
GAL_COORDS:       51.41, 18.18 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      275.43, 47.59 [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 Circular #42656
```
TITLE:   GCN CIRCULAR
NUMBER:  42656
SUBJECT: Swift Trigger 1413695: a possible GRB 251112A
DATE:    25/11/12 22:04:25 GMT
FROM:    James DeLaunay at PSU 
```
A. Mei (INAF-OAB), J. J. DeLaunay (PSU), M. Ferro (INAF-OAB), R. Gupta (NASA GSFC) and M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 21:28:56 UT, the Swift Burst Alert Telescope (BAT) triggered and located a possible GRB 251112A (trigger=1413695). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 274.019, +24.226 which is
```
   RA(J2000) = 18h 16m 05s
   Dec(J2000) = 24d 13' 32"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a complex structure with a duration of about 60 sec. The peak count rate was ~600 counts/sec (15-350 keV), at ~25 sec after the trigger.
The XRT began observing the field at 21:30:22.7 UT, 86.9 seconds after the BAT trigger. No source was detected in 782 s of promptly downlinked data. We are waiting for the full dataset to detect and localise the XRT counterpart.
UVOT took a finding chart exposure of 150 seconds with the White filter starting 91 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.161.
Due to no credible afterglow candidate in the initial XRT and UVOT data, we for now call this a possible GRB while we wait for additional data for further inspection.
Burst Advocate for this burst is A. Mei (alessio.mei AT inaf.it). 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/)
GCN Circular #42665
S. Lanava (PSU), S. Dichiara (PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
We have analysed 847 s of XRT data for GRB 251112A, from 90 s to 939 s after the Swift trigger. The data comprise 64 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 274.0697, +24.1535 which is equivalent to:
```
RA (J2000): 18h 16m 16.72s
Dec(J2000): +24d 09' 12.5"
```
with an uncertainty of 4.1 arcsec (radius, 90% confidence).
The light curve can be modelled with a power-law decay with a decay index of alpha=3.14 (+0.34, -0.30).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 3.3 (+/-0.4). The best-fitting absorption column is 4.9 (+1.3, -1.1) x 10^21 cm^-2, in excess of the Galactic value of 1.8 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 2.2 x 10^-11 (1.1 x 10^-10) erg cm^-2 count^-1.
A summary of the WT-mode spectrum is thus:
```
Total column:	     4.9 (+1.3, -1.1) x 10^21 cm^-2
Galactic foreground: 1.8 x 10^21 cm^-2
Excess significance: 4.6 sigma
Photon index:	     3.3 (+/-0.4)
```
If the light curve continues to decay with a power-law decay index of 3.14, the count rate at T+24 hours will be 7.8 x 10^-9 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x 10^-19 (8.4 x 10^-19) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at https://www.swift.ac.uk/xrt_products/01413695.
This circular is an official product of the Swift-XRT team.
GCN Circular #42667
A.A. Breeveld (UCL-MSSL) and A. Mei (INAF-OAB) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 251112A 304 s after the BAT trigger (Mei et al., GCN Circ. 42656). No optical afterglow consistent with the XRT position (Lanava et al., GCN Circ. 42665) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

u_FC               304          553          246         >19.9
white              856          944           86         >20.0
uvw1               683          697           14         >17.2
uvm2               658          849           39         >17.6
uvw2               609          801           39         >18.0
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.158 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #42686
D. Sadaula (GSFC/UMBC), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), A. Mei (INAF-OAB) M. J. Moss (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC), T. Sakamoto (AGU) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+963 sec from the recent telemetry downlink, we report further analysis of BAT GRB 251112A (trigger #1413695) (Mei, et al., GCN Circ. 42656). The BAT ground-calculated position is RA, Dec = 274.081, 24.158 deg which is
```
   RA(J2000)  =  18h 16m 19.5s 
   Dec(J2000) = +24d 09' 28.8" 
```
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%.
The mask-weighted BAT light curve shows multi-peaked emission starting ~T-28 sec. T90 (15-350 keV) is 55.42 +- 6.65 sec (estimated error including systematics).
The time-averaged spectrum from T-28.30 to T+32.38 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.77 +- 0.75, and Epeak of 48.4 +- 11.9 keV (chi squared 86.37 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 7.6 +- 0.9 x 10^-07 erg/cm2 and the 1-sec peak flux measured from T+1.05 sec in the 15-150 keV band is 0.7 +- 0.1 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.86 +- 0.15 (chi squared 94.39 for 57 d.o.f.). All the quoted errors are at the 90% confidence level.
The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1413695

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Jochen Greiner, last update: 16-Nov-2025 [Disclaimer]