Gamma-ray Burst 240112C

(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 12 Jan 24 17:37:43 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1208389,   Seg_Num: 0
GRB_RA:          270.644d {+18h 02m 35s} (J2000),
                 270.891d {+18h 03m 34s} (current),
                 270.130d {+18h 00m 31s} (1950)
GRB_DEC:         +24.487d {+24d 29' 12"} (J2000),
                 +24.488d {+24d 29' 18"} (current),
                 +24.485d {+24d 29' 05"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3816 [cnts]    Image_Peak=685 [image_cnts]
TRIGGER_DUR:     0.512 [sec] 
TRIGGER_INDEX:   121     E_range: 15-50 keV
BKG_INTEN:       18240 [cnts]
BKG_TIME:        63431.28 SOD {17:37:11.28} UT
BKG_DUR:         8 [sec]
GRB_DATE:        20321 TJD;    12 DOY;   24/01/12
GRB_TIME:        63444.97 SOD {17:37:24.97} UT
GRB_PHI:         -37.65 [deg]
GRB_THETA:        34.94 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     74.00 [sigma]
IMAGE_SIGNIF:    20.03 [sigma]
MERIT_PARAMS:     +1  +0  +0  -1  +1  +6  +0  +0 -62  +0 
SUN_POSTN:       293.77d {+19h 35m 05s}  -21.64d {-21d 38' 17"}
SUN_DIST:         51.21 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      312.67d {+20h 50m 40s}  -22.61d {-22d 36' 38"}
MOON_DIST:        62.15 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       50.47, 21.12 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      270.87, 47.92 [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 = 325.57,17.07 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(1.0<100sec) coincident with the FERMI_GBM event (trignum=726773850).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 12 Jan 24 17:37:54 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      43
TRIGGER_NUM:     726773850
GRB_RA:          269.467d {+17h 57m 52s} (J2000),
                 269.704d {+17h 58m 49s} (current),
                 268.973d {+17h 55m 53s} (1950)
GRB_DEC:         +27.783d {+27d 46' 60"} (J2000),
                 +27.782d {+27d 46' 56"} (current),
                 +27.787d {+27d 47' 14"} (1950)
GRB_ERROR:       7.97 [deg radius, statistical plus systematic]
GRB_INTEN:       509 [cnts/sec]
DATA_SIGNIF:     25.90 [sigma]
INTEG_TIME:      1.024 [sec]
GRB_DATE:        20321 TJD;    12 DOY;   24/01/12
GRB_TIME:        63445.12 SOD {17:37:25.12} UT
GRB_PHI:         352.00 [deg]
GRB_THETA:        40.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO:      2.48
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      67%  GRB
2nd_MOST_LIKELY:  20%  Generic SGR
DETECTORS:       1,0,0, 1,1,0, 0,0,0, 0,0,0, 0,0,
SUN_POSTN:       293.77d {+19h 35m 05s}  -21.64d {-21d 38' 17"}
SUN_DIST:         54.62 [deg]   Sun_angle= 1.6 [hr] (West of Sun)
MOON_POSTN:      312.67d {+20h 50m 40s}  -22.61d {-22d 36' 36"}
MOON_DIST:        65.26 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       53.41, 23.26 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      269.25, 51.22 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240112734/quicklook/glg_lc_medres34_bn240112734.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 245.43,22.33 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the SWIFT_BAT event (trignum=1208389).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 12 Jan 24 17:38:12 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      57
TRIGGER_NUM:     726773850
GRB_RA:          264.020d {+17h 36m 05s} (J2000),
                 264.262d {+17h 37m 03s} (current),
                 263.517d {+17h 34m 04s} (1950)
GRB_DEC:         +26.410d {+26d 24' 36"} (J2000),
                 +26.396d {+26d 23' 47"} (current),
                 +26.440d {+26d 26' 25"} (1950)
GRB_ERROR:       3.03 [deg radius, statistical only]
DATA_SIGNIF:     32.60 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        20321 TJD;    12 DOY;   24/01/12
GRB_TIME:        63445.12 SOD {17:37:25.12} UT
GRB_PHI:         344.00 [deg]
GRB_THETA:        40.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:       293.77d {+19h 35m 05s}  -21.64d {-21d 38' 17"}
SUN_DIST:         55.90 [deg]   Sun_angle= 2.0 [hr] (West of Sun)
MOON_POSTN:      312.67d {+20h 50m 41s}  -22.61d {-22d 36' 33"}
MOON_DIST:        67.79 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       50.23, 27.40 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      261.71, 49.68 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240112734/quicklook/glg_lc_medres34_bn240112734.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_726773850.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the SWIFT_BAT event (trignum=1208389).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Fri 12 Jan 24 17:46:47 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     726773850
GRB_RA:          262.490d {+17h 29m 58s} (J2000),
                 262.724d {+17h 30m 54s} (current),
                 262.003d {+17h 28m 01s} (1950)
GRB_DEC:         +29.150d {+29d 08' 60"} (J2000),
                 +29.133d {+29d 07' 58"} (current),
                 +29.188d {+29d 11' 15"} (1950)
GRB_ERROR:       2.34 [deg radius, statistical only]
GRB_DATE:        20321 TJD;    12 DOY;   24/01/12
GRB_TIME:        63445.12 SOD {17:37:25.12} UT
GRB_PHI:         343.00 [deg]
GRB_THETA:        37.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       293.78d {+19h 35m 06s}  -21.64d {-21d 38' 13"}
SUN_DIST:         58.93 [deg]   Sun_angle= 2.1 [hr] (West of Sun)
MOON_POSTN:      312.76d {+20h 51m 03s}  -22.58d {-22d 35' 00"}
MOON_DIST:        70.67 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       52.74, 29.52 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      259.24, 52.31 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240112734/quicklook/glg_lc_medres34_bn240112734.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240112734/quicklook/glg_locplot_all_bn240112734.png
COMMENTS:        Fermi-GBM Final Position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
COMMENTS:        This notice was generated completely by automated pipeline processing.  
COMMENTS:        In the LAT Field-of-view.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=10466).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 12 Jan 24 17:39:26 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     1208389,   Seg_Num: 0
POINT_RA:        270.620d {+18h 02m 29s} (J2000)
POINT_DEC:       +24.462d {+24d 27' 44"} (J2000)
IMG_START_DATE:  20321 TJD;    12 DOY;   24/01/12
IMG_START_TIME:  63558.99 SOD {17:39:18.99} UT,   114.0 [sec] since BAT Trigger Time
COUNTS:          12    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        2    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 12 Jan 24 17:43:16 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1208389,   Seg_Num: 0
POINT_RA:        270.621d {+18h 02m 29s} (J2000)
POINT_DEC:       +24.462d {+24d 27' 42"} (J2000)
POINT_ROLL:      152.094d
IMG_START_DATE:  20321 TJD;    12 DOY;   24/01/12
IMG_START_TIME:  63565.05 SOD {17:39:25.05} UT,   120.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.559
N_STARS:         59
X_OFFSET:        300 [pixels]
Y_OFFSET:        405 [pixels]
X_MAX:           1259 [pixels]
Y_MAX:           1364 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw01208389000msufc0120.fits
SUN_POSTN:       293.77d {+19h 35m 06s}  -21.64d {-21d 38' 15"}
SUN_DIST:         51.19 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      312.72d {+20h 50m 54s}  -22.59d {-22d 35' 38"}
MOON_DIST:        62.17 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       50.44, 21.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      270.84, 47.90 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 12 Jan 24 17:43:26 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1208389,   Seg_Num: 0
POINT_RA:        270.621d {+18h 02m 29s} (J2000)
POINT_DEC:       +24.462d {+24d 27' 42"} (J2000)
POINT_ROLL:      152.094d
IMG_START_DATE:  20321 TJD;    12 DOY;   24/01/12
IMG_START_TIME:  63565.05 SOD {17:39:25.05} UT,   120.1 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        5.559
N_STARS:         59
X_OFFSET:        300 [pixels]
Y_OFFSET:        405 [pixels]
X_MAX:           1259 [pixels]
Y_MAX:           1364 [pixels]
DET_THRESH:      20
PHOTO_THRESH:    12
SL_URL:          sw01208389000msufc0120.fits
SUN_POSTN:       293.77d {+19h 35m 06s}  -21.64d {-21d 38' 15"}
SUN_DIST:         51.19 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      312.73d {+20h 50m 54s}  -22.59d {-22d 35' 36"}
MOON_DIST:        62.17 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       50.44, 21.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      270.84, 47.90 [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 12 Jan 24 17:43:35 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1208389,   Seg_Num: 0
GRB_RA:          270.6422d {+18h 02m 34.12s} (J2000),
                 270.8892d {+18h 03m 33.40s} (current),
                 270.1285d {+18h 00m 30.83s} (1950)
GRB_DEC:         +24.4882d {+24d 29' 17.5"} (J2000),
                 +24.4900d {+24d 29' 23.9"} (current),
                 +24.4863d {+24d 29' 10.7"} (1950)
GRB_ERROR:       4.7 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  20321 TJD;    12 DOY;   24/01/12
IMG_START_TIME:  63601.00 SOD {17:40:01.00} UT,   156.0 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       293.77d {+19h 35m 06s}  -21.64d {-21d 38' 15"}
SUN_DIST:         51.21 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      312.73d {+20h 50m 55s}  -22.59d {-22d 35' 34"}
MOON_DIST:        62.18 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       50.47, 21.12 [deg] galactic lon,lat of the burst
ECL_COORDS:      270.87, 47.93 [deg] ecliptic lon,lat of the burst
COMMENTS:        SWIFT-XRT Coordinates.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        TAM values, flux and significance fields are not valid.  
COMMENTS:        This position was automatically generated on the ground using  
COMMENTS:        Photon Counting data telemetered via TDRSS (SPER data).  
COMMENTS:        See http://www.swift.ac.uk/sper/docs.php for details.  
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:     Fri 12 Jan 24 17:44:44 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1208389,   Seg_Num: 0
POINT_RA:        270.621d {+18h 02m 29s} (J2000)
POINT_DEC:       +24.462d {+24d 27' 42"} (J2000)
ROLL:            152.094d
IMG_START_DATE:  20321 TJD;    12 DOY;   24/01/12
IMG_START_TIME:  63565.05 SOD {17:39:25.05} UT,   120.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     726773997
X_OFFSET:        619 [pixels]
Y_OFFSET:        724 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       779
Y_GRB_POS:       884
BINNING_INDEX:   1
IM_URL:          sw01208389000msuni0153.fits
SUN_POSTN:       293.77d {+19h 35m 06s}  -21.64d {-21d 38' 14"}
SUN_DIST:         51.20 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      312.74d {+20h 50m 58s}  -22.59d {-22d 35' 22"}
MOON_DIST:        62.18 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       50.44, 21.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      270.84, 47.90 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Image.  
COMMENTS:        The GRB Position came from the Window Position in the Mode Command.  
COMMENTS:        The image has 2x2 binning (compression).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 12 Jan 24 17:44:53 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1208389,   Seg_Num: 0
POINT_RA:        270.621d {+18h 02m 29s} (J2000)
POINT_DEC:       +24.462d {+24d 27' 42"} (J2000)
ROLL:            152.094d
IMG_START_DATE:  20321 TJD;    12 DOY;   24/01/12
IMG_START_TIME:  63565.05 SOD {17:39:25.05} UT,   120.1 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     726773997
X_OFFSET:        619 [pixels]
Y_OFFSET:        724 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       779
Y_GRB_POS:       884
BINNING_INDEX:   1
IM_URL:          sw01208389000msuni0153.fits
SUN_POSTN:       293.77d {+19h 35m 06s}  -21.64d {-21d 38' 14"}
SUN_DIST:         51.20 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      312.74d {+20h 50m 58s}  -22.59d {-22d 35' 20"}
MOON_DIST:        62.18 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       50.44, 21.13 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      270.84, 47.90 [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 #35522
R. A. J. Eyles-Ferris (U Leicester), J.D. Gropp (PSU), S. Laha (GSFC/UMBC), F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester), D. M. Palmer (LANL), M. H. Siegel (PSU) and M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:
At 17:37:24 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240112C (trigger=1208389). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 270.644, +24.487 which is
```
   RA(J2000) = 18h 02m 35s
   Dec(J2000) = +24d 29' 12"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). Due to a telemetry gap, the BAT lightcurve is not immediately available.
The XRT began observing the field at 17:39:18.9 UT, 114.0 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 270.64225, 24.48830 which is equivalent to:
```
   RA(J2000)  = 18h 02m 34.14s
   Dec(J2000) = +24d 29' 17.9"
```
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This location is 7.4 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 https://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. No spectrum from the promptly downlinked event data is yet available to determine the column density.
UVOT took a finding chart exposure of 115 seconds with the White filter starting 120 seconds after the BAT trigger. There is a candidate afterglow in the rapidly available 2.7'x2.7' sub-image at
```
  RA(J2000)  =	18:02:34.59 = 270.64414
  DEC(J2000) = +24:29:21.2  =  24.48923
```
with a 90%-confidence error radius of about 0.75 arc sec. This position is 7.4 arc sec. from the center of the XRT error circle. The estimated magnitude is 16.73 with a 1-sigma error of about 0.14. No correction has been made for the expected extinction corresponding to E(B-V) of 0.108.
Burst Advocate for this burst is R. A. J. Eyles-Ferris (raje1 AT leicester.ac.uk). 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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Fri 12 Jan 24 17:47:04 UT
NOTICE_TYPE:     Swift-UVOT Position
TRIGGER_NUM:     1208389,   Seg_Num: 0
GRB_RA:          270.6441d {+18h 02m 34.58s} (J2000),
                 270.8911d {+18h 03m 33.85s} (current),
                 270.1304d {+18h 00m 31.29s} (1950)
GRB_DEC:         +24.4892d {+24d 29' 21.1"} (J2000),
                 +24.4910d {+24d 29' 27.5"} (current),
                 +24.4873d {+24d 29' 14.3"} (1950)
GRB_ERROR:       0.8 [arcsec radius, statistical only]
GRB_MAG:         16.72 +/- 0.14 [mag]
FILTER:          10, White
IMG_START_DATE:  20321 TJD;    12 DOY;   24/01/12
IMG_START_TIME:  63562.00 SOD {17:39:22.00} UT,   117.0 [sec] since BAT Trigger Time
SUN_POSTN:       293.78d {+19h 35m 06s}  -21.64d {-21d 38' 13"}
SUN_DIST:         51.21 [deg]   Sun_angle= 1.5 [hr] (West of Sun)
MOON_POSTN:      312.76d {+20h 51m 04s}  -22.58d {-22d 34' 56"}
MOON_DIST:        62.19 [deg]
MOON_ILLUM:      2 [%]
GAL_COORDS:       50.47, 21.12 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      270.87, 47.93 [deg] ecliptic lon,lat of the burst (or transient)
COMMENTS:        SWIFT UVOT Position Notice.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        Result based on Genie data.  
COMMENTS:        Notice generated automatically.

GCN Circular #35525
V. Lipunov, V.Kornilov, E. Gorbovskoy, K. Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.Senik, D. Vlasenko, G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij (Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O.A. Gress, N.M. Budnev, O.Ershova (Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich (Blagoveschensk Educational State University)
MASTER-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the Swift GRB 240112C ( R. A. J. Eyles-Ferris et al., GCN 35522) errorbox 8981 sec after notice time and 9002 sec after trigger time at 2024-01-12 20:07:27 UT, with upper limit up to 15.4 mag. The observations began at zenith distance = 85 deg. The sun altitude is -45.5 deg.
The galactic latitude b = 21 deg., longitude l = 51 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2354458
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

    9040 |        MASTER-Tunka |   C |    75 | 12.4 |        
    9124 |        MASTER-Tunka |   C |    70 | 15.4 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #35530
A. S. Moskvitin and O. A. Maslennikova (SAO RAS) report on behalf of the GRB follow-up team.
We observed the field of Swift GRB 240112C (Eyles-Ferris et al., GCN #35522) with the 1-m telescope of SAO RAS equipped with the CCD photometer. We obtained 21 x 60 sec. images in Rc band on January 13, 03:00:16--03:34:31 UT (t_mid - T0 = 0.40277 days) under mediocre weather conditions.
We did not detect any significant source at the OT position down to the limiting magnitude R_lim = 21.1 (based on R2 magnitudes of nearby USNO-B1 stars).
GCN Circular #35531
K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), E. Ambrosi (INAF-IASFPA) , J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), D.N. Burrows (PSU) and P.A. Evans report on behalf of the Swift-XRT team:
We have analysed 6.3 ks of XRT data for GRB 240112C, from 97 s to 45.8 ks after the BAT trigger. The data comprise 39 s in Windowed Timing (WT) mode (the first 10 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. Using 2660 s of PC mode data and 6 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 270.64402, +24.48893 which is equivalent to:
```
RA (J2000): 18h 02m 34.56s
Dec(J2000): +24d 29' 20.2"
```
with an uncertainty of 2.0 arcsec (radius, 90% confidence).
The light curve can be modelled with an initial power-law decay with an index of alpha=0.61 (+0.04, -0.48), followed by a break at T+5970 s to an alpha of 1.30 (+0.18, -0.20).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.92 (+0.14, -0.13). The best-fitting absorption column is 2.0 (+0.5, -0.4) x 10^21 cm^-2, in excess of the Galactic value of 1.3 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 3.6 x 10^-11 (4.8 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     2.0 (+0.5, -0.4) x 10^21 cm^-2
Galactic foreground: 1.3 x 10^21 cm^-2
Excess significance: 2.5 sigma
Photon index:	     1.92 (+0.14, -0.13)
```
If the light curve continues to decay with a power-law decay index of 1.30, the count rate at T+24 hours will be 0.015 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.3 x 10^-13 (7.0 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/01208389.
This circular is an official product of the Swift-XRT team.
GCN Circular #35533
P. Veres (UAH), R. Hamburg (CNRS/IN2P3), A. Myers (NPP/GSFC) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 17:37:25.12 UT on 12 January 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240112C (trigger 726773850/240112734). GRB 240112C was also localized by Swift BAT and XRT (Eyles-Ferris et al., GCN #35522). The Fermi GBM on-ground Localization is consistent with the Swift position.
The angle from the Fermi LAT boresight is 43 degrees.
The GBM light curve consists of two pulses with a duration (T90) of about 5.3 s (50-300 keV). The time-averaged spectrum from T0-0.6 to T0+6.3 s is best fit by a Band function with with Epeak= 71 +/- 6 keV, alpha = -1.26 +/- 0.08 and beta = -2.34 +/- 0.10.
The event fluence (10-1000 keV) in this time interval is (4.8 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.064 s in the 10-1000 keV band is 20.2 +/- 0.4 ph/s/cm^2.
The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN Circular #35534
N. P. M. Kuin (UCL-MSSL) and Eyles-Ferris (U. Leicester) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 240112C 121 s after the BAT trigger (Eyles-Ferris et al., GCN Circ. 35522). A source consistent with the XRT position is detected in the initial UVOT exposures.
The preliminary UVOT position is:
```
    RA  (J2000) =  18:02:34.58 = 270.64410 (deg.)
    Dec (J2000) = +24:29:21.3  =  24.48925 (deg.)
```
with an estimated uncertainty of 0.43 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white              121          236          113         16.98 +/- 0.04
v                 4955         5126          169        >18.6
b                 4340         4539          197         19.35 +/- 0.16
u                 4134         4334          197         19.11 +/- 0.18
w1                3930         4129          197         19.13 +/- 0.24
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.108 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #35536
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner= (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (= Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, L. Sza= kszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Po= valac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r= .o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovs= ky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.)= , Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. B= ozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eot= vos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hi= sadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Ki= ss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.= ), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima = U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo)= , T. Kano (U. Michigan) -- the GRBAlpha collaboration.
The long-duration GRB 240112C (Swift/BAT detection: GCN 35522; Fermi/GBM de= tection: GCN 35533; INTEGRAL/SPI-ACS detection: trigger no. 10466; Konus/Wi= nd trigger at 2024-01-12 17:37:21.633 UT) was observed by the GRBAlpha 1U C= ubeSat (Pal et al. 2023, A&A, 677, 40; arXiv:2302.10048).
The detection was confirmed at the peak time 2024-01-12 17:37:25 UTC. The T= 90 duration measured by GRBAlpha is 5 s and the overall significance during= T90 reaches 12 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.ko= nkoly.hu/static/share/GRB240112C_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/he= a/GRBAlpha/=20 GRBAlpha, launched on 2021 March 22, is a demonstration mission for a futur= e CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GR= BAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM ar= ray, covering the energy range from ~50 keV to ~1000 keV. To increase the d= uty cycle and the downlink rate, the upgrade of the on-board data acquisiti= on software stack is in progress. The ground segment is also supported by t= he radio amateur community and it takes advantage of the SatNOGS network fo= r increased data downlink volume.=20
GCN Circular #35539
A. Ridnaia, D. Frederiks, A. Lysenko, D. Svinkin, A. Tsvetkova, M. Ulanov, and T. Cline, on behalf of the Konus-Wind team, report:
The long-duration GRB 240112C (Swift-BAT detection: Eyles-Ferris et al., GCN 35522; Fermi-GBM detection: Veres at al., GCN 35533; GRBAlpha detection: Dafcikova et al., GCN 34436) triggered Konus-Wind at T0=63441.633 s UT (17:37:21.633).
The burst light curve shows a double-peaked structure, which starts at ~T0-0.5 s and has a total duration of ~4 s. The emission is seen up to ~2 MeV.
The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB240112_T63441/
As observed by Konus-Wind, the burst had a fluence of 3.70(-0.39,+0.46)x10^-6 erg/cm2, and a 64-ms peak flux, measured from T0+2.384 s, of 3.30(-0.84,+0.88)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst (measured from T0 to T0+8.448 s) is best fit in the 20 keV - 10 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -1.59(-0.22,+0.26) and Ep = 79(-18,+18) keV (chi2 = 66/74 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.3 (chi2 = 64/73 dof).
All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.
GCN Circular #35545
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werne= r (Masaryk U.), M. Ohno (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Obs= ervatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. = Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rez= enov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Researc= h Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (= Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (= Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory), T. = Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K= . Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gro= mes (VZLU), I. Vertat (FEL ZCU) -- the VZLUSAT-2/GRB payload collaboration= .
The long-duration GRB 240112C (Swift/BAT detection: GCN 35522; Fermi/GBM de= tection: GCN 35533; GRBAlpha detection: GCN 35536; Konus/Wind detection: GC= N 35539; INTEGRAL/SPI-ACS detection: trigger no. 10466) was detected by the= GRB detector on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz= /en/).
The data acquisition was performed by the GRB detector unit no. 1. The dete= ction was confirmed at the peak time 2024-01-12 17:37:27 UTC. The T90 durat= ion is 3 s and the significance during T90 reaches 14 sigma.
The light curve obtained by VZLUSAT-2 is available here: https://vzlusat2.konkoly.hu/static/share/GRB240112C_GCN_VZLUSAT2.pdf
All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/
The GRB detectors on VZLUSAT-2 are a demonstration payload for a future Cub= eSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLU= SAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x= 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range= from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from = Cape Canaveral.
GCN Circular #35546
C.C. Cheung, M. Kerr, J. E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge (MSFC), and M.S. Briggs (UAH) report:
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240112C, which was also detected by Swift/BAT, Fermi/GBM, GRBAlpha, Konus-Wind, VZLUSAT-2 (GCN #35522, #35533, #35536, #35539, #35545), and INTEGRAL/SPI-ACS (Trigger no. 10466).
Using an adaptive window with a resolution of 32-ms, the burst onset is det= ermined to be 2024-01-12 17:37:23.592 with a duration of 4.10 s and a total= significance of about 20.1 sigma. The light curve comprises two primary p= eaks.
Using a standard power-law function with an exponential high-energy cutoff = [3] to model the emission over this duration results in a photon index dN/d= E~E^x of x=3D1.6 and a cutoff energy ("Epeak") of 185 keV. The modeled 10-= 10000 keV fluence is 7.5e-07 erg/cm^2.
The analysis results presented here are preliminary and use a response func= tion that lacks a detailed characterization of the surrounding passive stru= cture of the ISS.
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost ga= mma-ray transient telescopes developed, built, and operated by the U.S. Nav= al Research Laboratory (NRL) with support from the University of Alabama in= Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard = the Department of Defense Space Test Program=E2=80=99s STP-H9 to the ISS. = The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering= the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length= ) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2= /3 sky) over a wide energy band of 50 keV to >2 MeV.
```
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
```
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