Gamma-ray Burst 240222A

(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 22 Feb 24 08:51:49 UT
NOTICE_TYPE:     Swift-BAT GRB Position
TRIGGER_NUM:     1216804,   Seg_Num: 0
GRB_RA:          143.248d {+09h 32m 59s} (J2000),
                 143.358d {+09h 33m 26s} (current),
                 143.019d {+09h 32m 05s} (1950)
GRB_DEC:         -68.029d {-68d 01' 43"} (J2000),
                 -68.137d {-68d 08' 11"} (current),
                 -67.806d {-67d 48' 21"} (1950)
GRB_ERROR:       3.00 [arcmin radius, statistical only]
GRB_INTEN:       3160 [cnts]    Image_Peak=205 [image_cnts]
TRIGGER_DUR:     1.024 [sec] 
TRIGGER_INDEX:   155     E_range: 50-350 keV
BKG_INTEN:       14313 [cnts]
BKG_TIME:        31879.04 SOD {08:51:19.04} UT
BKG_DUR:         8 [sec]
GRB_DATE:        20362 TJD;    53 DOY;   24/02/22
GRB_TIME:        31891.32 SOD {08:51:31.32} UT
GRB_PHI:         -157.90 [deg]
GRB_THETA:        24.29 [deg]
SOLN_STATUS:     0x20000003
RATE_SIGNIF:     29.22 [sigma]
IMAGE_SIGNIF:    9.35 [sigma]
MERIT_PARAMS:     +1  +0  +0  +0  +3  +0  +0  +0 +19  +0 
SUN_POSTN:       335.15d {+22h 20m 37s}  -10.32d {-10d 19' 18"}
SUN_DIST:        101.09 [deg]   Sun_angle= -11.2 [hr] (East of Sun)
MOON_POSTN:      133.33d {+08h 53m 20s}  +22.40d {+22d 24' 01"}
MOON_DIST:        90.84 [deg]
MOON_ILLUM:      96 [%]
GAL_COORDS:      286.00,-11.95 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      208.61,-70.03 [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 = 201.49,-6.57 [deg].  
COMMENTS:           
COMMENTS:        NOTE: This BAT event is temporally(0.0<100sec) coincident with the FERMI_GBM event (trignum=730284696).

red DSS finding chart ps-file

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Thu 22 Feb 24 08:52:01 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      48
TRIGGER_NUM:     730284696
GRB_RA:          154.083d {+10h 16m 20s} (J2000),
                 154.234d {+10h 16m 56s} (current),
                 153.771d {+10h 15m 05s} (1950)
GRB_DEC:         -69.700d {-69d 42' 00"} (J2000),
                 -69.821d {-69d 49' 14"} (current),
                 -69.450d {-69d 26' 59"} (1950)
GRB_ERROR:       15.27 [deg radius, statistical plus systematic]
GRB_INTEN:       227 [cnts/sec]
DATA_SIGNIF:     9.60 [sigma]
INTEG_TIME:      1.024 [sec]
GRB_DATE:        20362 TJD;    53 DOY;   24/02/22
GRB_TIME:        31891.47 SOD {08:51:31.47} UT
GRB_PHI:         100.00 [deg]
GRB_THETA:       115.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO:      0.45
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,1, 0,0,0, 0,0,0, 0,1,0, 0,0,
SUN_POSTN:       335.15d {+22h 20m 37s}  -10.32d {-10d 19' 18"}
SUN_DIST:         99.85 [deg]   Sun_angle= -11.9 [hr] (East of Sun)
MOON_POSTN:      133.33d {+08h 53m 20s}  +22.40d {+22d 23' 59"}
MOON_DIST:        93.42 [deg]
MOON_ILLUM:      96 [%]
GAL_COORDS:      290.15,-10.77 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      216.86,-67.05 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240222369/quicklook/glg_lc_medres34_bn240222369.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 131.23,19.43 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(0.0<100sec) coincident with the SWIFT_BAT event (trignum=1216804).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Thu 22 Feb 24 09:00:56 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     730284696
GRB_RA:          143.260d {+09h 33m 02s} (J2000),
                 143.428d {+09h 33m 43s} (current),
                 142.912d {+09h 31m 39s} (1950)
GRB_DEC:         -60.380d {-60d 22' 47"} (J2000),
                 -60.488d {-60d 29' 15"} (current),
                 -60.157d {-60d 09' 26"} (1950)
GRB_ERROR:       9.07 [deg radius, statistical only]
GRB_DATE:        20362 TJD;    53 DOY;   24/02/22
GRB_TIME:        31891.47 SOD {08:51:31.47} UT
GRB_PHI:         109.00 [deg]
GRB_THETA:       109.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       335.16d {+22h 20m 39s}  -10.32d {-10d 19' 10"}
SUN_DIST:        108.58 [deg]   Sun_angle= -11.2 [hr] (East of Sun)
MOON_POSTN:      133.41d {+08h 53m 38s}  +22.38d {+22d 22' 36"}
MOON_DIST:        83.27 [deg]
MOON_ILLUM:      96 [%]
GAL_COORDS:      280.68, -6.39 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      190.66,-66.23 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240222369/quicklook/glg_lc_medres34_bn240222369.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240222369/quicklook/glg_locplot_all_bn240222369.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:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=10586).

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Feb 24 08:53:11 UT
NOTICE_TYPE:     Swift-XRT Nack-Position
TRIGGER_NUM:     1216804,   Seg_Num: 0
POINT_RA:        143.262d {+09h 33m 03s} (J2000)
POINT_DEC:       -68.038d {-68d 02' 15"} (J2000)
IMG_START_DATE:  20362 TJD;    53 DOY;   24/02/22
IMG_START_TIME:  31985.36 SOD {08:53:05.36} UT,   94.0 [sec] since BAT Trigger Time
COUNTS:          2    Min_needed= 20
STD_DEV:         0.00   Max_StdDev_for_Good=28.44 [arcsec]
PH2_ITER:        1    Max_iter_allowed= 4
ERROR_CODE:      1
COMMENTS:        SWIFT-XRT Nack Position.  
COMMENTS:        No source found in the image.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Feb 24 08:55:42 UT
NOTICE_TYPE:     Swift-BAT GRB Lightcurve
TRIGGER_NUM:     1216804,   Seg_Num: 0
GRB_RA:          143.248d {+09h 32m 59s} (J2000),
                 143.358d {+09h 33m 26s} (current),
                 143.019d {+09h 32m 05s} (1950)
GRB_DEC:         -68.029d {-68d 01' 43"} (J2000),
                 -68.137d {-68d 08' 11"} (current),
                 -67.806d {-67d 48' 21"} (1950)
GRB_DATE:        20362 TJD;    53 DOY;   24/02/22
GRB_TIME:        31891.32 SOD {08:51:31.32} UT
TRIGGER_INDEX:   155
GRB_PHI:         -157.90 [deg]
GRB_THETA:        24.29 [deg]
DELTA_TIME:      51.00 [sec]
TRIGGER_DUR:     1.024 [sec] 
SOLN_STATUS:     0x3
RATE_SIGNIF:     29.22 [sigma]
IMAGE_SIGNIF:    9.35 [sigma]
LC_URL:          sw01216804000msb.lc
SUN_POSTN:       335.16d {+22h 20m 38s}  -10.32d {-10d 19' 15"}
SUN_DIST:        101.09 [deg]   Sun_angle= -11.2 [hr] (East of Sun)
MOON_POSTN:      133.37d {+08h 53m 28s}  +22.39d {+22d 23' 25"}
MOON_DIST:        90.83 [deg]
MOON_ILLUM:      96 [%]
GAL_COORDS:      286.00,-11.95 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      208.61,-70.03 [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 = 201.49,-6.57 [deg].

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Feb 24 08:56:07 UT
NOTICE_TYPE:     Swift-UVOT Source List
TRIGGER_NUM:     1216804,   Seg_Num: 0
POINT_RA:        143.262d {+09h 33m 03s} (J2000)
POINT_DEC:       -68.038d {-68d 02' 17"} (J2000)
POINT_ROLL:      191.934d
IMG_START_DATE:  20362 TJD;    53 DOY;   24/02/22
IMG_START_TIME:  31989.65 SOD {08:53:09.65} UT,   98.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.072
N_STARS:         190
X_OFFSET:        445 [pixels]
Y_OFFSET:        619 [pixels]
X_MAX:           1404 [pixels]
Y_MAX:           1578 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw01216804000msufc0098.fits
SUN_POSTN:       335.16d {+22h 20m 38s}  -10.32d {-10d 19' 15"}
SUN_DIST:        101.08 [deg]   Sun_angle= -11.2 [hr] (East of Sun)
MOON_POSTN:      133.37d {+08h 53m 29s}  +22.39d {+22d 23' 21"}
MOON_DIST:        90.83 [deg]
MOON_ILLUM:      96 [%]
GAL_COORDS:      286.01,-11.96 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      208.64,-70.03 [deg] ecliptic lon,lat of the pointing direction
COMMENTS:        SWIFT-UVOT Source List.

GCN NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Feb 24 08:56:24 UT
NOTICE_TYPE:     Swift-UVOT Processed Source List
TRIGGER_NUM:     1216804,   Seg_Num: 0
POINT_RA:        143.262d {+09h 33m 03s} (J2000)
POINT_DEC:       -68.038d {-68d 02' 17"} (J2000)
POINT_ROLL:      191.934d
IMG_START_DATE:  20362 TJD;    53 DOY;   24/02/22
IMG_START_TIME:  31989.65 SOD {08:53:09.65} UT,   98.3 [sec] since BAT Trigger Time
FILTER:          10, White
BKG_MEAN:        2.072
N_STARS:         190
X_OFFSET:        445 [pixels]
Y_OFFSET:        619 [pixels]
X_MAX:           1404 [pixels]
Y_MAX:           1578 [pixels]
DET_THRESH:      12
PHOTO_THRESH:    6
SL_URL:          sw01216804000msufc0098.fits
SUN_POSTN:       335.16d {+22h 20m 38s}  -10.32d {-10d 19' 14"}
SUN_DIST:        101.08 [deg]   Sun_angle= -11.2 [hr] (East of Sun)
MOON_POSTN:      133.37d {+08h 53m 29s}  +22.39d {+22d 23' 18"}
MOON_DIST:        90.83 [deg]
MOON_ILLUM:      96 [%]
GAL_COORDS:      286.01,-11.96 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      208.64,-70.03 [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 22 Feb 24 08:57:32 UT
NOTICE_TYPE:     Swift-UVOT Image
TRIGGER_NUM:     1216804,   Seg_Num: 0
POINT_RA:        143.262d {+09h 33m 03s} (J2000)
POINT_DEC:       -68.038d {-68d 02' 17"} (J2000)
ROLL:            191.934d
IMG_START_DATE:  20362 TJD;    53 DOY;   24/02/22
IMG_START_TIME:  31989.65 SOD {08:53:09.65} UT,   98.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     730284822
X_OFFSET:        764 [pixels]
Y_OFFSET:        938 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       924
Y_GRB_POS:       1098
BINNING_INDEX:   1
IM_URL:          sw01216804000msuni0131.fits
SUN_POSTN:       335.16d {+22h 20m 38s}  -10.32d {-10d 19' 13"}
SUN_DIST:        101.08 [deg]   Sun_angle= -11.2 [hr] (East of Sun)
MOON_POSTN:      133.38d {+08h 53m 31s}  +22.39d {+22d 23' 08"}
MOON_DIST:        90.83 [deg]
MOON_ILLUM:      96 [%]
GAL_COORDS:      286.01,-11.96 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      208.64,-70.03 [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 22 Feb 24 08:57:40 UT
NOTICE_TYPE:     Swift-UVOT Processed Image
TRIGGER_NUM:     1216804,   Seg_Num: 0
POINT_RA:        143.262d {+09h 33m 03s} (J2000)
POINT_DEC:       -68.038d {-68d 02' 17"} (J2000)
ROLL:            191.934d
IMG_START_DATE:  20362 TJD;    53 DOY;   24/02/22
IMG_START_TIME:  31989.65 SOD {08:53:09.65} UT,   98.3 [sec] since BAT Trigger Time
FILTER:          10, White
EXPOSURE_ID:     730284822
X_OFFSET:        764 [pixels]
Y_OFFSET:        938 [pixels]
WIDTH:           160 [pixels]
HEIGHT:          160 [pixels]
X_GRB_POS:       924
Y_GRB_POS:       1098
BINNING_INDEX:   1
IM_URL:          sw01216804000msuni0131.fits
SUN_POSTN:       335.16d {+22h 20m 38s}  -10.32d {-10d 19' 13"}
SUN_DIST:        101.08 [deg]   Sun_angle= -11.2 [hr] (East of Sun)
MOON_POSTN:      133.38d {+08h 53m 32s}  +22.39d {+22d 23' 07"}
MOON_DIST:        90.83 [deg]
MOON_ILLUM:      96 [%]
GAL_COORDS:      286.01,-11.96 [deg] galactic lon,lat of the pointing direction
ECL_COORDS:      208.64,-70.03 [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:     Thu 22 Feb 24 08:57:17 UT
NOTICE_TYPE:     Swift-XRT Position
TRIGGER_NUM:     1216804,   Seg_Num: 0
GRB_RA:          143.2267d {+09h 32m 54.40s} (J2000),
                 143.3363d {+09h 33m 20.70s} (current),
                 142.9981d {+09h 32m 00.44s} (1950)
GRB_DEC:         -68.0321d {-68d 01' 55.5"} (J2000),
                 -68.1398d {-68d 08' 23.4"} (current),
                 -67.8094d {-67d 48' 33.9"} (1950)
GRB_ERROR:       3.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  20362 TJD;    53 DOY;   24/02/22
IMG_START_TIME:  32000.00 SOD {08:53:20.00} UT,   108.7 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       335.16d {+22h 20m 38s}  -10.32d {-10d 19' 14"}
SUN_DIST:        101.09 [deg]   Sun_angle= -11.2 [hr] (East of Sun)
MOON_POSTN:      133.38d {+08h 53m 31s}  +22.39d {+22d 23' 10"}
MOON_DIST:        90.82 [deg]
MOON_ILLUM:      96 [%]
GAL_COORDS:      285.99,-11.96 [deg] galactic lon,lat of the burst
ECL_COORDS:      208.61,-70.04 [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 0.58% < P(seren) < 1.1%.

GCN Circular #35769
The Fermi GBM team reports the detection of a likely LONG GRB
At 08:51:31 UT on 22 Feb 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240222A (trigger 730284696.466782 / 240222369).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 143.3, Dec = -60.4 (J2000 degrees, equivalent to J2000 09h 33m, -60d 23'), with a statistical uncertainty of 9.1 degrees.
The angle from the Fermi LAT boresight is 109.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240222369/quicklook/glg_skymap_all_bn240222369.png
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240222369/quicklook/glg_healpix_all_bn240222369.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn240222369/quicklook/glg_lc_medres34_bn240222369.gif
GCN Circular #35770
P. D'Avanzo (INAF-OAB), R. Brivio (INAF-OAB), S. Dichiara (PSU), A. Y. Lien (U Tampa), K. L. Page (U Leicester), C. Salvaggio (INAF-OAB), T. Sbarrato (INAF-OAB) and B. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift Observatory Team:
At 08:51:31 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 240222A (trigger=1216804). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 143.248, -68.029 which is
```
   RA(J2000) = 09h 32m 59s
   Dec(J2000) = -68d 01' 43"
```
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi-peaked structure with a duration of about 20 sec. The peak count rate was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 08:53:05.3 UT, 94.0 seconds after the BAT trigger. Using promptly downlinked data we find a fading, uncatalogued X-ray source located at RA, Dec 143.22556, -68.03102 which is equivalent to:
```
   RA(J2000)  = 09h 32m 54.13s
   Dec(J2000) = -68d 01' 51.7"
```
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This location is 31 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.
A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (1.72 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 4.6 (+3.44/-2.96) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter starting 98 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 0.166.
Burst Advocate for this burst is P. D'Avanzo (paolo.davanzo 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 NOTICE

TITLE:           GCN/SWIFT NOTICE
NOTICE_DATE:     Thu 22 Feb 24 09:30:48 UT
NOTICE_TYPE:     Swift-XRT Position UPDATE
TRIGGER_NUM:     1216804,   Seg_Num: 0
GRB_RA:          143.2249d {+09h 32m 53.97s} (J2000),
                 143.3345d {+09h 33m 20.27s} (current),
                 142.9963d {+09h 31m 59.12s} (1950)
GRB_DEC:         -68.0307d {-68d 01' 50.5"} (J2000),
                 -68.1384d {-68d 08' 18.3"} (current),
                 -67.8080d {-67d 48' 28.9"} (1950)
GRB_ERROR:       3.5 [arcsec radius, statistical plus systematic, 90% containment]
GRB_INTEN:       1.00e-10 [erg/cm2/sec]
GRB_SIGNIF:      10.00 [sigma]
IMG_START_DATE:  20362 TJD;    53 DOY;   24/02/22
IMG_START_TIME:  32000.00 SOD {08:53:20.00} UT,   108.7 [sec] since BAT Trigger Time
TAM[0-3]:        100.00 100.00 100.00 100.00
AMPLIFIER:       1
WAVEFORM:        31
SUN_POSTN:       335.18d {+22h 20m 43s}  -10.31d {-10d 18' 43"}
SUN_DIST:        101.09 [deg]   Sun_angle= -11.2 [hr] (East of Sun)
MOON_POSTN:      133.67d {+08h 54m 40s}  +22.30d {+22d 17' 57"}
MOON_DIST:        90.72 [deg]
MOON_ILLUM:      96 [%]
GAL_COORDS:      285.99,-11.96 [deg] galactic lon,lat of the burst
ECL_COORDS:      208.60,-70.04 [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:        The probability that this is a serendipitous source in the  
COMMENTS:        SPER window is 0.58% < P(seren) < 1.1%.

GCN Circular #35771
R. Brivio, Y.-D. Hu, P. D=E2=80=99Avanzo, M. Ferro, S. Covino, D. Fugazza (= INAF-OAB) on behalf of the REM team, report:
We observed the field of GRB 240222A (D'Avanzo et al., GCN 35770) with the REM 60cm robotic telescope located at the ESO observatory of La Silla (Chile). The observations were carried in the g, r, i, z, H bands, starting on 2024 February 22 at 08:52:40 UT (i.e. 69 seconds after the burst), and lasting for about 2 hours.
From a preliminary analysis, we find no source at the XRT position down to the following 3sigma magnitude upper limits:
H > 16.7 (Vega; calibrated against the 2MASS catalogue) at a mid-time of t - t0 =3D 342 s after the GRB trigger,
r > 18.7 (AB; calibrated against the APASS catalogue) at a mid-time of t - t0 =3D 485 s after the GRB trigger.
GCN Circular #35774
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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 240222A ( Fermi GBM team, GCN 35769) errorbox 33348 sec after notice time and 33382 sec after trigger time at 2024-02-22 18:07:54 UT, with upper limit up to 18.3 mag. Observations started at twilight. The observations began at zenith distance = 50 deg. The sun altitude is -10.1 deg.
The galactic latitude b = -6 deg., longitude l = 281 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2383850
We obtain a following upper limits.
```
Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   33473 | 2024-02-22 18:07:54 |         MASTER-SAAO | (09h 40m 49.96s , -68d 03m 28.5s) |   C |   180 | 17.9 |        
   33473 | 2024-02-22 18:07:54 |         MASTER-SAAO | (09h 18m 15.91s , -67d 52m 27.6s) |   C |   180 | 17.4 |        
   33672 | 2024-02-22 18:11:13 |         MASTER-SAAO | (09h 40m 56.74s , -68d 04m 32.3s) |   C |   180 | 18.3 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #35775
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-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 240222A ( P. D'Avanzo et al., GCN 35770) errorbox 33361 sec after notice time and 33382 sec after trigger time at 2024-02-22 18:07:54 UT, with upper limit up to 18.3 mag. Observations started at twilight. The observations began at zenith distance = 50 deg. The sun altitude is -10.1 deg.
The galactic latitude b = -12 deg., longitude l = 286 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2383830
We obtain a following upper limits.
```
Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   33473 |         MASTER-SAAO |   C |   180 | 17.9 |        
   33473 |         MASTER-SAAO |   C |   180 | 17.4 |        
   33672 |         MASTER-SAAO |   C |   180 | 18.3 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.
GCN Circular #35777
S. R. Oates (Lancaster. U) and P. D'Avanzo (INAF-OAB) report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 240222A 98s after the BAT trigger (D'Avanzo et al., GCN Circ 35770). No optical afterglow consistent with X-ray (D'Avanzo et al., GCN Circ. 35770) position 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 initial exposures are:
```
Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white          98            1192          205            >20.9
v              642           1068           58            >18.5
b              567           1168           58            >19.5
u              311           1142          285            >20.0
uvw1           691           1118           39            >18.3
uvm2           666           861            39            >18.0
uvw2           617           1044           58            >18.6
```
The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.16 in the direction of the burst (Schlegel et al. 1998).
GCN Circular #35778
J. Mangan (CNRS/IJCLab) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 08:51:31.47 UT on 22 February 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240222A (trigger 730284696/240222369). which was also detected by Swift BAT (P. D'Avanzo et al. 2024, GCN 35770). The Fermi GBM on-ground location is consistent with the Swift BAT position.
The angle from the Fermi LAT boresight is 109 degrees.
The GBM light curve consists of a single emission episode with a duration (T90) of about 3.8 s (50-300 keV). The time-averaged spectrum from T0-5.9 to T0+3.3 s is best fit by a simple power law function with index -1.4 +/- 0.1.
The event fluence (10-1000 keV) in this time interval is (9.2 +/- 1.9)E-07 erg/cm^2. The 1-sec peak photon flux measured starting from T0-0.19 s in the 10-1000 keV band is 4 +/- 0.7 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 #35780
A.P. Beardmore (U. Leicester), R. Brivio (INAF-OAB), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAR), S. Dichiara (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P. Osborne (U. Leicester) and P.A. Evans report on behalf of the Swift-XRT team:
We have analysed 6.6 ks of XRT data for GRB 240222A, from 106 s to 41.2 ks after the BAT trigger. The data comprise 9 s in Windowed Timing (WT) mode (taken while Swift was slewing), with the remainder in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 143.2254, -68.0305 which is equivalent to:
```
RA (J2000): 09 32 54.10
Dec(J2000): -68 01 49.7
```
with an uncertainty of 3.5 arcsec (radius, 90% confidence).
The light curve can be modelled with a power-law decay with a decay index of alpha=2.02 (+0.12, -0.11).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.52 (+0.24, -0.12). The best-fitting absorption column is consistent with the Galactic value of 1.7 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 4.6 x 10^-11 (5.3 x 10^-11) erg cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
```
Total column:	     1.7 (+/-0.9) x 10^21 cm^-2
Galactic foreground: 1.7 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.52 (+0.24, -0.12)
```
If the light curve continues to decay with a power-law decay index of 2.02, the count rate at T+24 hours will be 1.3 x 10^-5 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.8 x 10^-16 (6.7 x 10^-16) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01216804.
This circular is an official product of the Swift-XRT team.
GCN Circular #35781
H. A. Krimm (NSF), S. D. Barthelmy (GSFC), P. D'Avanzo (INAF-OAB), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), 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-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 240222A (trigger #1216804) (D'Avanzo et al., GCN Circ. 35770). The BAT ground-calculated position is RA, Dec = 143.209, -68.034 deg which is
```
   RA(J2000)  =  09h 32m 50.2s
   Dec(J2000) = -68d 02' 03.7"
```
with an uncertainty of 1.8 arcmin, (radius, sys+stat, 90% containment). The partial coding was 94%.
The mask-weighted light curve shows a main pulse that starts at ~T-0.4 s, peaks at ~T0, and ends at ~T+1.4 s. In addition, there is a small precursor pulse at ~T-2.7 s. T90 (15-350 keV) is 3.94 +- 2.35 sec (estimated error including systematics).
The time-averaged spectrum from T-2.70 to T+1.37 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 0.75 +- 0.23. The fluence in the 15-150 keV band is 2.5 +- 0.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.20 sec in the 15-150 keV band is 1.3 +- 0.2 ph/cm2/sec. 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/1216804/
GCN Circular #35782
Sheng-Lun Xie, Shao-Lin Xiong, Wen-Long Zhang report on behalf of the GECAM team:
GECAM-B was triggered in-flight and on-ground by a short burst, GRB 240222A, at 2024-02-22T08:51:31.500 UTC (T0), which was also observed by Fermi/GBM (GCN #35769 and GCN #35778) and Swift/BAT (GCN #35770 and GCN #35781).
According to the GECAM-B light curve, this burst consists of roughly a pulse with a total duration of ~3 sec.
The GECAM-B ground calculated location (J2000) is:
```
Ra: 169.76 deg   
Dec: -71.58 deg
Err: 14.01 deg (1-sigma, statistical only)
```
This GECAM-B localization is consistent with that of Swift/BAT within the error.
We note that these results are very preliminary. Refined analysis will be reported later.
Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS).
GCN Circular #35792
A. Pal (Konkoly Observatory), M. Dafcikova, J. Ripa, M. Kolar, N. Werner (M= asaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Kon= koly Observatory), N. Husarikova, F. Munz , M. Topinka, L. Szakszonova, J.-= P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U= . of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszl= o, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical= U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, = H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos= U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. F= riss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoy= a U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly O= bservatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (= Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogis= o, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U.= Michigan) -- the GRBAlpha collaboration.
The long-duration GRB 240222A (Fermi/GBM detection: GCN 35769; Swift/BAT de= tection: GCN 35770; GECAM-B detection: GCN 35782; INTEGRAL/SPI-ACS peak det= ection at 2024-02-22 ~08:51:32 UT) was observed by the GRBAlpha 1U CubeSat = (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A= ...677A..40P/abstract).
The detection was confirmed at the peak time 2024-02-22 08:51:31 UTC. The T= 90 duration measured by GRBAlpha is 1.5 s and the overall significance duri= ng T90 reaches 6.3 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240222A_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
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.
GCN Circular #35801
J. K. Leung (U. Toronto/HUJI), G. E. Anderson (Curtin University), S. Chastain (UNM), A. Gulati (U. Sydney), L. Rhodes (U. Oxford), A. J. van der Horst (GWU) on behalf of the PanRadio GRB collaboration
The Australia Telescope Compact Array (ATCA) performed observations of GRB 240222A (Fermi GBM Team, GCN 35769; D'Avanzo et al., GCN 35770) at 5.5, 9, 16.7 and 21.2 GHz as part of the Large ATCA "PanRadio GRB" follow-up programme C3542 (PI. Anderson). ATCA observed from 2024-02-24 12:00 UT to 22:00 UT. In our preliminary analysis, we find no radio source coincident with the refined XRT position (Beardmore et al., GCN 35780) with 3 sigma upper limits of 75, 54, 69 and 159 microJy/beam at 5.5, 9.0, 16.7 and 21.2 GHz, respectively.
We thank the CSIRO Space and Astronomy staff for supporting these observations. We acknowledge the Gomeroi people as the traditional owners of the Observatory site. The Australia Telescope Compact Array is part of the Australia Telescope National Facility (https://ror.org/05qajvd42) which is funded by the Australian Government for operation as a National Facility managed by CSIRO.

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Jochen Greiner, last update: 26-Feb-2024 [Disclaimer]