Gamma-ray Burst 130131A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN/BACODINE POSITION NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 13:56:45 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     547407,   Seg_Num: 0
GRB_RA:          171.108d {+11h 24m 26s} (J2000),
                 171.288d {+11h 25m 09s} (current),
                 170.417d {+11h 21m 40s} (1950)
GRB_DEC:         +48.069d {+48d 04' 10"} (J2000),
                 +47.998d {+47d 59' 51"} (current),
                 +48.344d {+48d 20' 39"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       4473 [cnts]    Image_Peak=258 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   137     E_range: 15-50 keV
BKG_INTEN:       28306 [cnts]
BKG_TIME:        50165.83 SOD {13:56:05.83} UT
BKG_DUR:         8 [sec]
GRB_DATE:        16323 TJD;    31 DOY;   13/01/31
GRB_TIME:        50182.02 SOD {13:56:22.02} UT
GRB_PHI:         -87.22 [deg]
GRB_THETA:         9.75 [deg]
SOLN_STATUS:     0x3
RATE_SIGNIF:     13.22 [sigma]
IMAGE_SIGNIF:    9.89 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +1  +0  +0  +0 +73  +0 
SUN_POSTN:       314.32d {+20h 57m 17s}  -17.23d {-17d 13' 53"}
SUN_DIST:        136.95 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.17d {+12h 08m 40s}   -5.07d {-05d 04' 02"}
MOON_DIST:        53.92 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.08, 63.08 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      149.38, 39.90 [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 = 142.37,12.15 [deg].

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 13:57:52 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     547407,   Seg_Num: 0
GRB_RA:          171.1243d {+11h 24m 29.83s} (J2000),
                 171.3043d {+11h 25m 13.03s} (current),
                 170.4339d {+11h 21m 44.12s} (1950)
GRB_DEC:         +48.0750d {+48d 04' 30.0"} (J2000),
                 +48.0030d {+48d 00' 10.8"} (current),
                 +48.3498d {+48d 20' 59.3"} (1950)
GRB_ERROR:       4.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.22e-08 [erg/cm2/sec]
GRB_SIGNIF:      15.87 [sigma]
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50240.53 SOD {13:57:20.53} UT,   58.5 [sec] since BAT Trigger Time
TAM[0-3]:        327.65 237.22 261.63 243.64
AMPLIFIER:       2
WAVEFORM:        134
SUN_POSTN:       314.32d {+20h 57m 17s}  -17.23d {-17d 13' 52"}
SUN_DIST:        136.94 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.18d {+12h 08m 42s}   -5.07d {-05d 04' 14"}
MOON_DIST:        53.93 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.06, 63.08 [deg] galactic lon,lat of the burst
ECL_COORDS:      149.39, 39.91 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        The XRT position is 0.73 arcmin from the BAT position.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 13:58:02 UT
NOTICE_TYPE:     Swift-XRT Image
TRIGGER_NUM:     547407,   Seg_Num: 0
GRB_RA:          171.1243d {+11h 24m 29.8s} (J2000),
                 171.3043d {+11h 25m 13.0s} (current),
                 170.4339d {+11h 21m 44.1s} (1950)
GRB_DEC:         +48.0750d {+48d 04' 30.0"} (J2000),
                 +48.0030d {+48d 00' 10.8"} (current),
                 +48.3498d {+48d 20' 59.3"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       252 [cnts]
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50240.53 SOD {13:57:20.53} UT,   58.5 [sec] since BAT Trigger Time
CENTROID_X:      257.80,  raw= 258  [pixels]
CENTROID_Y:      289.46,  raw= 289  [pixels]
ROLL:            57.00 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -20.12
GRB_POS_XRT_Z:   -108.19
IMAGE_URL:       sw00547407000msxps_rw.img
SUN_POSTN:       314.32d {+20h 57m 17s}  -17.23d {-17d 13' 52"}
SUN_DIST:        136.94 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.18d {+12h 08m 43s}   -5.07d {-05d 04' 16"}
MOON_DIST:        53.93 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.06, 63.08 [deg] galactic lon,lat of the burst
ECL_COORDS:      149.39, 39.91 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 13:58:11 UT
NOTICE_TYPE:     Swift-XRT Processed Image
TRIGGER_NUM:     547407,   Seg_Num: 0
GRB_RA:          171.1243d {+11h 24m 29.8s} (J2000),
                 171.3043d {+11h 25m 13.0s} (current),
                 170.4339d {+11h 21m 44.1s} (1950)
GRB_DEC:         +48.0750d {+48d 04' 30.0"} (J2000),
                 +48.0030d {+48d 00' 10.8"} (current),
                 +48.3498d {+48d 20' 59.3"} (1950)
GRB_ERROR:       4.7 [arcsec, radius, statistical plus systematic]
GRB_INTEN:       252 [cnts]
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50240.53 SOD {13:57:20.53} UT,   58.5 [sec] since BAT Trigger Time
CENTROID_X:      257.80,  raw= 258  [pixels]
CENTROID_Y:      289.46,  raw= 289  [pixels]
ROLL:            57.00 [deg]
GAIN:            4
MODE:            3, Long Image mode
WAVEFORM:        134
EXPO_TIME:       2.50 [sec]
GRB_POS_XRT_Y:   -20.12
GRB_POS_XRT_Z:   -108.19
IMAGE_URL:       sw00547407000msxps_rw.img
SUN_POSTN:       314.32d {+20h 57m 17s}  -17.23d {-17d 13' 52"}
SUN_DIST:        136.94 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.18d {+12h 08m 43s}   -5.07d {-05d 04' 18"}
MOON_DIST:        53.93 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.06, 63.08 [deg] galactic lon,lat of the burst
ECL_COORDS:      149.39, 39.91 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Processed Image.  
COMMENTS:        The object found at this position is either a very bright burst or a cosmic ray hit.  
COMMENTS:        Examine the XRT Image to differentiate (CRs are much more compact); see examples at:  
COMMENTS:        http://www.swift.psu.edu/xrt/XRT_Postage_Stamp_Image_Photo_Gallery.htm .

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 13:59:55 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     547407,   Seg_Num: 0
GRB_RA:          171.108d {+11h 24m 26s} (J2000),
                 171.288d {+11h 25m 09s} (current),
                 170.417d {+11h 21m 40s} (1950)
GRB_DEC:         +48.069d {+48d 04' 10"} (J2000),
                 +47.998d {+47d 59' 51"} (current),
                 +48.344d {+48d 20' 39"} (1950)
GRB_DATE:        16323 TJD;    31 DOY;   13/01/31
GRB_TIME:        50182.02 SOD {13:56:22.02} UT
TRIGGER_INDEX:   137
GRB_PHI:         -87.22 [deg]
GRB_THETA:         9.75 [deg]
DELTA_TIME:      -18.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     13.22 [sigma]
IMAGE_SIGNIF:    9.89 [sigma]
LC_URL:          sw00547407000msb.lc
SUN_POSTN:       314.32d {+20h 57m 17s}  -17.23d {-17d 13' 51"}
SUN_DIST:        136.95 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.19d {+12h 08m 47s}   -5.08d {-05d 04' 38"}
MOON_DIST:        53.93 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.08, 63.08 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      149.38, 39.90 [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 = 142.37,12.15 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 14:00:21 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.083d {+11h 24m 20s} (J2000)
POINT_DEC:       +48.063d {+48d 03' 49"} (J2000)
POINT_ROLL:      57.005d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50249.70 SOD {13:57:29.70} UT,   67.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.655
N_STARS:         15
X_OFFSET:        624 [pixels]
Y_OFFSET:        512 [pixels]
X_MAX:           1583 [pixels]
Y_MAX:           1471 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00547407000msufc0067.fits
SUN_POSTN:       314.32d {+20h 57m 18s}  -17.23d {-17d 13' 50"}
SUN_DIST:        136.97 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.20d {+12h 08m 47s}   -5.08d {-05d 04' 43"}
MOON_DIST:        53.93 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.12, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 14:00:48 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.083d {+11h 24m 20s} (J2000)
POINT_DEC:       +48.063d {+48d 03' 49"} (J2000)
POINT_ROLL:      57.005d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50249.70 SOD {13:57:29.70} UT,   67.7 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.655
N_STARS:         15
X_OFFSET:        624 [pixels]
Y_OFFSET:        512 [pixels]
X_MAX:           1583 [pixels]
Y_MAX:           1471 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00547407000msufc0067.fits
SUN_POSTN:       314.32d {+20h 57m 18s}  -17.23d {-17d 13' 50"}
SUN_DIST:        136.97 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.20d {+12h 08m 48s}   -5.08d {-05d 04' 48"}
MOON_DIST:        53.93 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.12, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [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:     Thu 31 Jan 13 14:02:00 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.083d {+11h 24m 20s} (J2000)
POINT_DEC:       +48.063d {+48d 03' 49"} (J2000)
ROLL:            57.005d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50249.70 SOD {13:57:29.70} UT,   67.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     381333459
X_OFFSET:        1018 [pixels]
Y_OFFSET:        798 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1178
Y_GRB_POS:       958
BINNING_INDEX:   1
IM_URL:          sw00547407000msuni0078.fits
SUN_POSTN:       314.32d {+20h 57m 18s}  -17.23d {-17d 13' 49"}
SUN_DIST:        136.97 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.21d {+12h 08m 51s}   -5.08d {-05d 05' 01"}
MOON_DIST:        53.94 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.12, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [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:        All 4 attachments are included.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 14:01:47 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.083d {+11h 24m 20s} (J2000)
POINT_DEC:       +48.063d {+48d 03' 49"} (J2000)
ROLL:            57.005d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50249.70 SOD {13:57:29.70} UT,   67.7 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     381333459
X_OFFSET:        1018 [pixels]
Y_OFFSET:        798 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1178
Y_GRB_POS:       958
BINNING_INDEX:   1
IM_URL:          sw00547407000msuni0078.fits
SUN_POSTN:       314.32d {+20h 57m 18s}  -17.23d {-17d 13' 49"}
SUN_DIST:        136.97 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.21d {+12h 08m 50s}   -5.08d {-05d 04' 59"}
MOON_DIST:        53.94 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.12, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [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:     Thu 31 Jan 13 14:07:32 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.080d {+11h 24m 19s} (J2000)
POINT_DEC:       +48.062d {+48d 03' 43"} (J2000)
POINT_ROLL:      57.003d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50461.63 SOD {14:01:01.63} UT,   279.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.478
N_STARS:         9
X_OFFSET:        698 [pixels]
Y_OFFSET:        478 [pixels]
X_MAX:           1657 [pixels]
Y_MAX:           1437 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    3
SL_URL:          sw00547407000msufc0279.fits
SUN_POSTN:       314.33d {+20h 57m 19s}  -17.23d {-17d 13' 45"}
SUN_DIST:        136.97 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.26d {+12h 09m 02s}   -5.10d {-05d 06' 04"}
MOON_DIST:        53.96 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.13, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 14:07:50 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.080d {+11h 24m 19s} (J2000)
POINT_DEC:       +48.062d {+48d 03' 43"} (J2000)
POINT_ROLL:      57.003d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50461.63 SOD {14:01:01.63} UT,   279.6 [sec] since BAT Trigger Time
FILTER:          7, U
BKG_MEAN:        0.478
N_STARS:         9
X_OFFSET:        698 [pixels]
Y_OFFSET:        478 [pixels]
X_MAX:           1657 [pixels]
Y_MAX:           1437 [pixels]
DET_THRESH:      6
PHOTO_THRESH:    3
SL_URL:          sw00547407000msufc0279.fits
SUN_POSTN:       314.33d {+20h 57m 19s}  -17.23d {-17d 13' 45"}
SUN_DIST:        136.97 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.26d {+12h 09m 03s}   -5.10d {-05d 06' 08"}
MOON_DIST:        53.97 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.13, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [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:     Thu 31 Jan 13 14:08:13 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     547407,   Seg_Num: 0
GRB_RA:          171.1229d {+11h 24m 29.49s} (J2000),
                 171.3029d {+11h 25m 12.70s} (current),
                 170.4325d {+11h 21m 43.78s} (1950)
GRB_DEC:         +48.0762d {+48d 04' 34.3"} (J2000),
                 +48.0042d {+48d 00' 15.1"} (current),
                 +48.3510d {+48d 21' 03.6"} (1950)
GRB_ERROR:       3.3 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50297.00 SOD {13:58:17.00} UT,   115.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       314.33d {+20h 57m 19s}  -17.23d {-17d 13' 45"}
SUN_DIST:        136.94 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.27d {+12h 09m 04s}   -5.10d {-05d 06' 12"}
MOON_DIST:        53.97 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.06, 63.08 [deg] galactic lon,lat of the burst
ECL_COORDS:      149.39, 39.91 [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.  
COMMENTS:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.11% < P(seren) < 0.58%.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 14:08:48 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.080d {+11h 24m 19s} (J2000)
POINT_DEC:       +48.062d {+48d 03' 43"} (J2000)
ROLL:            57.003d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50461.63 SOD {14:01:01.63} UT,   279.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     381333671
X_OFFSET:        1018 [pixels]
Y_OFFSET:        798 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1178
Y_GRB_POS:       958
BINNING_INDEX:   1
IM_URL:          sw00547407000msuni0290.fits
SUN_POSTN:       314.33d {+20h 57m 19s}  -17.23d {-17d 13' 45"}
SUN_DIST:        136.98 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.27d {+12h 09m 05s}   -5.11d {-05d 06' 19"}
MOON_DIST:        53.97 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.13, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [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:     Thu 31 Jan 13 14:09:07 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.080d {+11h 24m 19s} (J2000)
POINT_DEC:       +48.062d {+48d 03' 43"} (J2000)
ROLL:            57.003d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  50461.63 SOD {14:01:01.63} UT,   279.6 [sec] since BAT Trigger Time
FILTER:          7, U
EXPOSURE_ID:     381333671
X_OFFSET:        1018 [pixels]
Y_OFFSET:        798 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1178
Y_GRB_POS:       958
BINNING_INDEX:   1
IM_URL:          sw00547407000msuni0290.fits
SUN_POSTN:       314.33d {+20h 57m 19s}  -17.23d {-17d 13' 44"}
SUN_DIST:        136.98 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.27d {+12h 09m 06s}   -5.11d {-05d 06' 22"}
MOON_DIST:        53.97 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.13, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [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:        All 4 attachments are included.

GCN Circular #14156
D. Grupe (PSU), B. N. Barlow (PSU), S. D. Barthelmy (GSFC), A. P. Beardmore (U Leicester), S. T. Holland (STScI), J. A. Kennea (PSU), C. B. Markwardt (NASA/GSFC), F. E. Marshall (NASA/GSFC), C. Pagani (U Leicester), B. Sbarufatti (INAF-OAB/PSU), M. H. Siegel (PSU), M. Stamatikos (OSU/NASA/GSFC), R. L. C. Starling (U Leicester) and T. N. Ukwatta (MSU) report on behalf of the Swift Team:
At 13:56:22 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 130131A (trigger=547407). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 171.108, +48.069 which is
```
   RA(J2000)  =  11h 24m 26s
   Dec(J2000) = +48d 04' 10"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows two peak: 1 5-sec peak at T+0 sec and a 100-sec peak at T+50 sec. with a total duration of about 60 sec. The peak count rate was ~1400 counts/sec (15-350 keV), at ~1 sec after the trigger.
The XRT began observing the field at 13:57:20.5 UT, 58.5 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 171.12193, 48.07520 which is equivalent to:
```
   RA(J2000)  = 11h 24m 29.26s
   Dec(J2000) = +48d 04' 30.7"
```
with an uncertainty of 4.4 arcseconds (radius, 90% containment). This location is 40 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. We cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.45 x 10^20 cm^-2 (Kalberla et al. 2005).
The initial flux in the 2.5 s image was 1.22e-08 erg cm^-2 s^-1 (0.2-10 keV).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 67 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 100% of the XRT 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 XRT 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 0.01.
Burst Advocate for this burst is D. Grupe (dxg35 AT 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:     Thu 31 Jan 13 14:13:44 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.080d {+11h 24m 19s} (J2000)
POINT_DEC:       +48.062d {+48d 03' 43"} (J2000)
POINT_ROLL:      57.003d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  51039.90 SOD {14:10:39.90} UT,   857.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.610
N_STARS:         42
X_OFFSET:        458 [pixels]
Y_OFFSET:        238 [pixels]
X_MAX:           1897 [pixels]
Y_MAX:           1677 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00547407000msufc0857.fits
SUN_POSTN:       314.33d {+20h 57m 20s}  -17.23d {-17d 13' 41"}
SUN_DIST:        136.98 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.31d {+12h 09m 15s}   -5.12d {-05d 07' 15"}
MOON_DIST:        53.99 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.13, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 31 Jan 13 14:14:04 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.080d {+11h 24m 19s} (J2000)
POINT_DEC:       +48.062d {+48d 03' 43"} (J2000)
POINT_ROLL:      57.003d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  51039.90 SOD {14:10:39.90} UT,   857.9 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        1.610
N_STARS:         42
X_OFFSET:        458 [pixels]
Y_OFFSET:        238 [pixels]
X_MAX:           1897 [pixels]
Y_MAX:           1677 [pixels]
DET_THRESH:      11
PHOTO_THRESH:    5
SL_URL:          sw00547407000msufc0857.fits
SUN_POSTN:       314.33d {+20h 57m 20s}  -17.23d {-17d 13' 41"}
SUN_DIST:        136.98 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.32d {+12h 09m 16s}   -5.12d {-05d 07' 19"}
MOON_DIST:        53.99 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.13, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [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:     Thu 31 Jan 13 14:15:02 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.080d {+11h 24m 19s} (J2000)
POINT_DEC:       +48.062d {+48d 03' 43"} (J2000)
ROLL:            57.003d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  51039.90 SOD {14:10:39.90} UT,   857.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     381334250
X_OFFSET:        1017 [pixels]
Y_OFFSET:        797 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1177
Y_GRB_POS:       957
BINNING_INDEX:   1
IM_URL:          sw00547407000msuni0868.fits
SUN_POSTN:       314.33d {+20h 57m 20s}  -17.23d {-17d 13' 40"}
SUN_DIST:        136.98 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.33d {+12h 09m 18s}   -5.13d {-05d 07' 30"}
MOON_DIST:        54.00 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.13, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [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:     Thu 31 Jan 13 14:15:13 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     547407,   Seg_Num: 0
POINT_RA:        171.080d {+11h 24m 19s} (J2000)
POINT_DEC:       +48.062d {+48d 03' 43"} (J2000)
ROLL:            57.003d
IMG_START_DATE:  16323 TJD;    31 DOY;   13/01/31
IMG_START_TIME:  51039.90 SOD {14:10:39.90} UT,   857.9 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     381334250
X_OFFSET:        1017 [pixels]
Y_OFFSET:        797 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       1177
Y_GRB_POS:       957
BINNING_INDEX:   1
IM_URL:          sw00547407000msuni0868.fits
SUN_POSTN:       314.33d {+20h 57m 20s}  -17.23d {-17d 13' 40"}
SUN_DIST:        136.98 [deg]   Sun_angle= 9.5 [hr] (West of Sun)
MOON_POSTN:      182.33d {+12h 09m 18s}   -5.13d {-05d 07' 32"}
MOON_DIST:        54.00 [deg]
MOON_ILLUM:      81 [%]
GAL_COORDS:      156.13, 63.07 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      149.37, 39.89 [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 #14157
N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick), T. Wold (JACH) report on behalf of a larger collaboration:
We observed the field of GRB 130131A (Grupe et al. GCN 14166) with the WFCAM camera on UKIRT, beginning approximately 54 mins after the BAT trigger.
Within the XRT error circle we detect a single, bright point source at position:
11 24 30.39 +48 04 33.3 (J2000, uncertainty ~0.5")
Provisional Vega magnitudes (relative to a nearby 2MASS source) are K=16.4, J=19.4, indicating a rather red source.
Further observations and analysis are ongoing.
GCN Circular #14158
F.J. Virgili (LJMU), C. Guidorzi (U. Ferrara), and A. Melandri (INAF-OAB) report:
"The 2-m Faulkes Telescope North robotically followed up GRB 130131A (Swift trigger 547407, Grupe et al. GCN 14156) 2.88 min after the GRB trigger time. No optical counterpart is detected within the XRT error circle to the following conservative limits:
```
Midtime from GRB    Exposure    Filter    Magnitude
       (min)                        (s)
-------------------------------------------------
       3.4                       3x10s         R        >19.2
       28.9                      720s          R        >20.6
       33.7                      700s          i'        >20.1
-------------------------------------------------
```
Magnitudes are calibrated with nearby USNOB-1 and SDSS stars."
GCN Circular #14160
P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team.
Using 574 s of XRT Photon Counting mode data and 1 UVOT images for GRB 130131A, 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 = 171.12621, +48.07589 which is equivalent to:
```
RA (J2000): 11h 24m 30.29s
Dec (J2000): +48d 04' 33.2"
```
with an uncertainty of 1.8 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, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN Circular #14163
D. M. Palmer (LANL), 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), A. Lien (GSFC/ORAU), C. B. Markwardt (GSFC), T. Sakamoto (AGU), G. Sato (ISAS), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (MSU) (i.e. the Swift-BAT team):
Using the data set from T-239 to T+903 sec from the recent telemetry downlink, we report further analysis of BAT GRB 130131A (trigger #547407) (Grupe, et al., GCN Circ. 14156). The BAT ground-calculated position is RA, Dec = 171.091, 48.064 deg which is
```
   RA(J2000)  =  11h 24m 21.9s 
   Dec(J2000) = +48d 03' 51.0" 
```
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment). The partial coding was 97%.
The mask-weighted light curve shows two separated peaks: (1) starting at ~T-5 sec, peaking at ~T+1 sec, and ending at ~T+15 sec, and (2) T+35, T+47, and ~T+65 sec. T90 (15-350 keV) is 51.6 +- 2.4 sec (estimated error including systematics).
The time-averaged spectrum from T-0.95 to T+52.15 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.12 +- 0.32. The fluence in the 15-150 keV band is 3.1 +- 0.6 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.04 sec in the 15-150 keV band is 0.7 +- 0.1 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/547407/BA/
GCN Circular #14166
D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ), S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto) and N. Kawai(Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 130131A (Grupe et al., GCNC 14156) with the optical three color (g', Rc and Ic) CCD camera attached to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
The observation started on 2013-01-31 14:53:53 UT (~58 min after the burst). We did not find any new point source within the enhanced XRT circle (Evans et al., GCNC 14160) in all the three bands.
Three sigma upper limits of the OT are listed below. We used SDSS catalog for flux calibration.
```
T0+[day]   MID-UT   T-EXP[sec]    g'     Rc     Ic
------------------------------------------------------
0.10111    16:21:58    9000.0   >20.5  >20.5  >19.9
------------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]
```
GCN Circular #14168
J.A. Kennea (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), O.M. Littlejohns (U. Leicester), A. Maselli (INAF-IASFPA), V. Mangano (INAF-IASFPA), A. Melandri (INAF-OAB) and D. Grupe report on behalf of the Swift-XRT team:
We have analysed 9.2 ks of XRT data for GRB 130131A (Grupe et al. GCN Circ. 14156), from 64 s to 18.8 ks after the BAT trigger. The data comprise 235 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 14160).
The late-time light curve (from T0+5.3 ks) can be modelled with a power-law decay with a decay index of alpha=1.1 (+0.4, -0.3).
A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.44 (+/-0.07). The best-fitting absorption column is 3.17 (+/-0.19) x 10^21 cm^-2, in excess of the Galactic value of 1.4 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 2.21 (+0.21, -0.20) and a best-fitting absorption column of 2.4 (+/-0.6) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.6 x 10^-11 (6.1 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     2.4 (+/-0.6) x 10^21 cm^-2
Galactic foreground: 1.4 x 10^20 cm^-2
Excess significance: 6.5 sigma
Photon index:	     2.21 (+0.21, -0.20)
```
If the light curve continues to decay with a power-law decay index of 1.1, the count rate at T+24 hours will be 2.6 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.3 x 10^-14 (1.6 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/00547407.
This circular is an official product of the Swift-XRT team.
GCN Circular #14171
T. Laskar, B. A. Zauderer and E. Berger (Harvard) report on behalf of the CARMA Key Project "A Millimeter View of the Transient Universe":
"We observed the position of GRB 130131A (Grupe et al.; GCN 14156) beginning 2013 Feb 1.28 (dt=0.7 d) at a mean frequency of 5.8 Ghz with the Karl G. Jansky Very Large Array. We detect a source consistent with the enhanced Swift-XRT position (Evans et al.; GCN 14160) with a flux of 38 (+/- 11) uJy. The position of this radio source is
```
 RA (J2000)    11:24:30.4  (+/- 0.2)
DEC (J2000)   +48:04:33.0  (+/- 1.5).
```
Follow-up observations at multiple frequencies are in progress. We thank the VLA staff for their support."
GCN Circular #14172
B. A. Zauderer, E. Berger, and T. Laskar (Harvard) report on behalf of the CARMA Key Project "A Millimeter View of the Transient Universe":
"We observed the position of GRB 130131A (Grupe et al., GCN 14156) with the Combined Array for Research in Millimeter Astronomy beginning 2013 Feb 1.3 UT (0.7 d post-burst) at a mean frequency of ~85 GHz. Coincident with the Swift-XRT position (Evans et al., GCN 14160) and the VLA 5.8 GHz position (Laskar et al., GCN 14171), we report a preliminary detection of a radio source with a flux of ~0.5 mJy. Further analysis is in progress.
We thank the CARMA staff for their support."
GCN Circular #14175
N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick), T. Wold (JACH) report on behalf of a larger collaboration:
We re-observed the field of GRB 130131A with the WFCAM camera on UKIRT, beginning approximately 20.5 hr post-burst. The source reported by us previously (GCN 14157) is no longer detected in our provisional reduction, indicating a fading of at least 2 mag in the K-band. This confirms the source as the afterglow of the GRB (consistent also with the radio detection by Zauderer et al. GCN 14171).
We also report that the afterglow was faintly visible in a Z-band image taken at UKIRT 2hr post-burst (in morning twilight), indicating that this is likely not an extreme redshift event.
GCN Circular #14177
J. Wren, W.T. Vestrand, P. Wozniak, and H. Davis, of Los Alamos National Laboratory report:
The RAPTOR network of robotic optical telescopes made observations of Swift trigger 547407 (Grupe, et al., GCN 14156). The burst location was within the field of our wide-field monitor located in Maui, HI, which began a 10 s integration of the location at 13:56:20.65 UT, 1.4 s before the Swift trigger time and during the gamma-ray emitting interval. During the period that the BAT was detecting gamma-ray emission, from ~T-5 s to ~T+65 s (Palmer, et al., GCN 14163), we have a total of four 10 s exposures with limiting magnitudes of R~9.4 in moderate moonglow. We do not detect the optical counterpart (Tanvir et al., GCN 14157; Virgili et al., GCN 14158) in any of our images. Our 3-sigma limiting magnitudes are based on a comparison of our unfiltered image to the Tycho-2 V-band catalog.
GCN Circular #14178
Ori Fox (UCB), Nat Butler (ASU), Alan M. Watson (UNAM), Alexander=20 Kutyrev (GSFC), William H. Lee (UNAM), Michael G. Richer (UNAM), Chris Klein (UCB), J. Xavier Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara (UCSC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC), Jos=C3=88 A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes=CB=99s Gonz=C2=B7lez (UNAM), Carlos Rom=C2=B7n-Z=CB=99=C3=92iga (UNAM), Neil Gehrels (GSFC), and Harvey Moseley (GSFC) report:
Under good weather conditions, we observed the field of GRB 130131A=20 (Grupe, et al., GCN 14156) with the Reionization and Transients Infrared=20 Camera (RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at=20 the Observatorio Astron=C3=9Bmico Nacional on Sierra San Pedro M=C2=B7rti= r. An=20 extremely red (K=3D16.4, J=3D19.4) afterglow candidate was detected by=20 Tanvir, et al. (GCN 14157). We obtained approximately 2.83 hrs (ri) and=20 1.07 hrs (ZYJH) of data from 2013 February 1.25 to 2023 February 1.42=20 UTC (16.0 to 20.0 hrs after the BAT trigger)
We detect no source within the XRT error circle (Evans et al; GCN 14160)=20 or at the position of the UKIRT source (GCN 14157). In comparison with=20 SDSS DR8 and 2MASS, we derive the following upper limits (3-sigma) in=20 the AB magnitude system:
```
r' > 23.8
i' > 23.3
Z > 22.2
Y > 21.8
J > 21.9
H > 21.5
```
The limits are consistent with the suggested fading of at least 2 mag in K-band (GCN 14175) measured at 20.5 hours.
These magnitudes are not corrected for Galactic extinction in the direction of the GRB.
We thank the staff of the Observatorio Astron=C3=9Bmico Nacional in San Pedro M=C2=B7rtir.
Please make note of the new email address. http://astro.berkeley.edu/~ofox/website/Homepage.html
GCN Circular #14180
M. H. Siegel and D. Grupe (PSU) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 130131A 68 s after the BAT trigger (Grupe et al., GCN Circ. 14156). No optical afterglow consistent with the optical position (Tanver et al., GCN Circ 14157) or XRT position (Evans et al., GCN Circ. 14160) 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

white_FC            68          217          147         >21.8
u_FC               280          529          246         >20.8
white               68         7570          839         >22.5
v                  609        18681         1378         >21.0
b                  535         7369          549         >21.7
u                  280        13670         1434         >22.0
w1                 658        12906         1434         >21.7
m2                1932        18851         1263         >21.3
w2                 758        17768         1336         >22.0
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #14182
A. Volnova (SAI MSU/IKI), I. Korobtsev (ISTP), E. Klunko (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the Swift GRB 130131A (Grupe et al., GCN 14156) with AZT-33IK telescope of Sayan observatory (Mondy). We took several images in R-filter of 60 s exposure on Jan. 31, between (UT) 14:12:36-15:36:53 under favorable weather conditions with a FWHM of about 2.5". In the stacked images we detected a source which is coincident with the source reported by Tanvir et al. (GCN 14157). The photometry based on SDSS DR8 is the following:
```
  t_start,      T0+ (mid), filter,  exp.,   OT+/-err      UL (3 sigma)
  (UT)          d                   s

  14:12:36      0.01640    R       10x60    22.5 +/-0.35  22.4
  14:12:36      0.04053    R       79x60    23.4 +/-0.25  23.5
```
Taken coincidence with source detected in IR (Tanvir et al. GCN 14157) and fading nature of the source we suggest that we detect OT of GRB 130131A. The detection in R filter confirms that the GRB 130131A is not an extreme redshift event (Tanvir et al. GCN 14175). Also we compared fluxes in X-ray and optic at ~0.016 days after trigger and found that the GRB 130131A can be considered as optically dark burst following the both criteria (Jakobsson et al., 2004; van der Horst et al., 2009).
The stars used for photometry and assumed R mags:
```
J112419.01+480710.6 11:24:19.01 +48:07:10.7 R = 18.93
J112414.86+480528.8 11:24:14.86 +48:05:28.9 R = 18.77
J112419.60+480357.4 11:24:19.61 +48:03:57.5 R = 20.32
```
The finding chart of the stacked image can be found in http://grb.rssi.ru/GRB130131A/GRB130131A_130131_AZT33IK.png
GCN Circular #14194
M. Hayashi, T. Yoshii, R. Usui, Y.Aoki, S. Kurita, Y. Saito, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed GRB 130131A (Grupe et al., GCNC 14156) with the optical three color (g, Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.
The observation started on 2013-01-31 13:57:11 UT ( ~49 sec after the burst). And we could not find any new point source within the XRT error circle in all the three bands. The results of photometry (3 sigma upper limits) are listed below.
The photon flux were calibrated against GSC2.3 catalog.
```
T0+[sec]   MID-UT   T-EXP[sec]    g'           Rc          Ic
-------------------------------------------------------------------------------------------
     33       13:57:44      60        >17.6   >17.8   >17.1
    159      13:59:51      270      >18.5   >18.6   >18.0
   1105     14:15:46      1440     >19.0   >19.4   >18.9
   7119     15:56:00      9540     >19.9   >20.6   >19.8
-------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst [sec]
T-EXP: Total Exposure time [sec]
```
GCN Report 424.1
GCN_Report 424.1 has been posted: http://gcn.gsfc.nasa.gov/reports/report_424_1.pdf by D. Grupe at PSU titled: "Swift Observations of GRB 130131A"
GCN Circular #14281
I.A. Smith (Rice U.), R.P.J. Tilanus (Leiden Observatory), N.R. Tanvir (U. of Leicester), D.A. Frail (NRAO) report:
We observed the location of GRB 130131A (Grupe et al., GCN Circ. 14156) twice using the SCUBA-2 sub-millimeter continuum camera on the James Clerk Maxwell Telescope. The first observation started at 14:36 UT on 2013-01-31, corresponding to 40 minutes after the burst trigger. It lasted 2.0 hours in good weather conditions. The second observation started at 12:40 UT on 2013-02-01, corresponding to 0.95 days after the burst trigger. It lasted 2.1 hours in good weather conditions. No source was significantly detected in the individual or combined observations at the VLA location (Laskar et al., GCN Circ. 14171). The combined RMS was 2.2 mJy/beam at 850 microns and 18.2 mJy/beam at 450 microns.
We thank Iain Coulson, Jim Hoge, Callie McNew, Alexander Karim, and William Montgomerie for their prompt support of these observations.
photometric redshift z = 1.55 +0.02 -0.04
of host-galaxy: G. Schroeder et al. 2022, ApJ 940, 53

Back to JG's homepage

Jochen Greiner, last update: 17-Jan-2023 [Disclaimer]