- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Sat 31 Dec 22 21:46:08 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 48
TRIGGER_NUM: 694215970
GRB_RA: 331.983d {+22h 07m 56s} (J2000),
332.234d {+22h 08m 56s} (current),
331.438d {+22h 05m 45s} (1950)
GRB_DEC: +35.950d {+35d 57' 00"} (J2000),
+36.063d {+36d 03' 47"} (current),
+35.705d {+35d 42' 17"} (1950)
GRB_ERROR: 7.30 [deg radius, statistical plus systematic]
GRB_INTEN: 675 [cnts/sec]
DATA_SIGNIF: 17.70 [sigma]
INTEG_TIME: 0.256 [sec]
GRB_DATE: 19944 TJD; 365 DOY; 22/12/31
GRB_TIME: 78365.13 SOD {21:46:05.13} UT
GRB_PHI: 79.00 [deg]
GRB_THETA: 50.00 [deg]
DATA_TIME_SCALE: 0.2560 [sec]
HARD_RATIO: 0.54
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 87% GRB
2nd_MOST_LIKELY: 9% Cyg X-1
DETECTORS: 1,1,1, 0,0,1, 0,0,0, 1,1,0, 0,0,
SUN_POSTN: 281.09d {+18h 44m 22s} -23.04d {-23d 02' 37"}
SUN_DIST: 76.34 [deg] Sun_angle= -3.4 [hr] (East of Sun)
MOON_POSTN: 30.62d {+02h 02m 29s} +11.51d {+11d 30' 29"}
MOON_DIST: 57.81 [deg]
MOON_ILLUM: 69 [%]
GAL_COORDS: 89.47,-16.09 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 350.83, 43.62 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221231907/quicklook/glg_lc_medres34_bn221231907.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 224.47,13.95 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Sat 31 Dec 22 21:46:22 UT
NOTICE_TYPE: Fermi-GBM Ground Position
RECORD_NUM: 60
TRIGGER_NUM: 694215970
GRB_RA: 331.890d {+22h 07m 34s} (J2000),
332.161d {+22h 08m 39s} (current),
331.302d {+22h 05m 12s} (1950)
GRB_DEC: +21.730d {+21d 43' 48"} (J2000),
+21.843d {+21d 50' 35"} (current),
+21.485d {+21d 29' 06"} (1950)
GRB_ERROR: 5.44 [deg radius, statistical only]
DATA_SIGNIF: 19.80 [sigma]
DATA_INTERVAL: 0.256 [sec]
GRB_DATE: 19944 TJD; 365 DOY; 22/12/31
GRB_TIME: 78365.13 SOD {21:46:05.13} UT
GRB_PHI: 68.00 [deg]
GRB_THETA: 61.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 4173 (Gnd S/W Version number)
SUN_POSTN: 281.09d {+18h 44m 22s} -23.04d {-23d 02' 37"}
SUN_DIST: 66.98 [deg] Sun_angle= -3.4 [hr] (East of Sun)
MOON_POSTN: 30.62d {+02h 02m 29s} +11.51d {+11d 30' 33"}
MOON_DIST: 56.63 [deg]
MOON_ILLUM: 69 [%]
GAL_COORDS: 79.76,-27.09 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 342.76, 30.92 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221231907/quicklook/glg_lc_medres34_bn221231907.gif
POS_MAP_URL: http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_694215970.fits
COMMENTS: Fermi-GBM Ground-calculated Coordinates.
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.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Sat 31 Dec 22 21:56:19 UT
NOTICE_TYPE: Fermi-GBM Final Position
RECORD_NUM: 0
TRIGGER_NUM: 694215970
GRB_RA: 332.680d {+22h 10m 43s} (J2000),
332.931d {+22h 11m 44s} (current),
332.134d {+22h 08m 32s} (1950)
GRB_DEC: +36.490d {+36d 29' 24"} (J2000),
+36.604d {+36d 36' 14"} (current),
+36.243d {+36d 14' 36"} (1950)
GRB_ERROR: 5.20 [deg radius, statistical only]
GRB_DATE: 19944 TJD; 365 DOY; 22/12/31
GRB_TIME: 78365.13 SOD {21:46:05.13} UT
GRB_PHI: 80.00 [deg]
GRB_THETA: 50.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 41731 (Gnd S/W Version number)
SUN_POSTN: 281.10d {+18h 44m 23s} -23.04d {-23d 02' 35"}
SUN_DIST: 77.11 [deg] Sun_angle= -3.5 [hr] (East of Sun)
MOON_POSTN: 30.70d {+02h 02m 49s} +11.55d {+11d 32' 48"}
MOON_DIST: 57.40 [deg]
MOON_ILLUM: 69 [%]
GAL_COORDS: 90.28,-15.99 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 351.87, 43.82 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221231907/quicklook/glg_lc_medres34_bn221231907.gif
LOC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221231907/quicklook/glg_locplot_all_bn221231907.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: This is likely a Long GRB.
- GCN Circular #33129
The Fermi GBM team reports the detection of a likely LONG GRB
At 21:46:05 UT on 31 Dec 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 221231A (trigger 694215970.129412 / 221231907).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 332.7, Dec = 36.5 (J2000 degrees, equivalent to J2000 22h 10m, 36d 30'), with a statistical uncertainty of 5.2 degrees.
The angle from the Fermi LAT boresight is 50.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221231907/quicklook/glg_skymap_all_bn221231907.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221231907/quicklook/glg_healpix_all_bn221231907.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn221231907/quicklook/glg_lc_medres34_bn221231907.gif
- GCN Circular #33132
Swift/BAT did not localize GRB 221231A onboard (T0:
2022-12-31T21:46:05 UTC, Fermi/GBM GCN 33129).
The Fermi notice, distributed in near real-time, triggered the Swift
Mission Operations Center operated Gamma-ray Urgent Archiver for Novel
Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).
Upon trigger by this notice, GUANO sent a command to the Swift Burst
Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from
[-50,+150] seconds around the time of the burst. All the requested
event mode data was delivered to the ground.
The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu,
arXiv:2111.01769), detects the burst in a 0.256 s analysis time bin
with a sqrt(TS) of 14.
An arcminute localization is found with DeltaLLHOut of 18.2 and a
DeltaLLHPeak of 7.9.
The burst duration as seen by BAT is less than 0.5 seconds.
See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief
descriptions and interpretations of sqrt(TS), DeltaLLHPeak, and
DeltaLLHOut.
The BAT position is
RA, Dec = 336.260, +25.138 deg which is
RA(J2000) = 22h 25m 02.47s
Dec(J2000) = +25d 08′ 18.6″
with an estimated uncertainty of 5 arcmin radius.
XRT and UVOT follow-up has been requested.
Results of follow-up observations will be reported in future circulars.
GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.
A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/
- GCN Circular #33133
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the Swift/BAT-GUANO GRB 221231A.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021534
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Swift/BAT-GUANO event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a
GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
- GCN Circular #33135
M. Perri (SSDC & INAF-OAR), A. Tohuvavohu (U. Toronto), D.N. Burrows
(PSU), J. D. Gropp (PSU), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (SSDC & INAF-OAR),
B. Sbarufatti (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf
of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the
Swift/BAT-GUANO-detected burst GRB 221231A, collecting 5.0 ks of Photon
Counting (PC) mode data between T0+32.4 ks and T0+44.3 ks.
Five uncatalogued X-ray sources have been detected, however none of
them is above the RASS limit or shows definitive signs of fading.
Therefore, at the present time we cannot identify which, if any, is the
afterglow. Sources 2 and 5 are inside the error box of Swift/BAT-GUANO,
but source 5 is associated with a known source. Details of these
sources are given below:
Source 1:
RA (J2000.0): 336.3458 = 22:25:22.98
Dec (J2000.0): +25.1723 = +25:10:20.3
Error: 6.5 arcsec (radius, 90% conf.)
Count-rate: (9.1 [+7.3, -5.4])e-4 ct s^-1
Distance: 303 arcsec from Swift/BAT-GUANO position.
Source 2:
RA (J2000.0): 336.2560 = 22:25:1.44
Dec (J2000.0): +25.1298 = +25:07:47.2
Error: 3.1 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: 0.0107 [+0.0022, -0.0020] ct s^-1
Distance: 34 arcsec from Swift/BAT-GUANO position.
Flux: (5.44 [+1.13, -1.00])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 3:
RA (J2000.0): 336.2019 = 22:24:48.46
Dec (J2000.0): +25.0298 = +25:01:47.3
Error: 5.4 arcsec (radius, 90% conf.)
Count-rate: (1.87 [+0.97, -0.73])e-3 ct s^-1
Distance: 435 arcsec from Swift/BAT-GUANO position.
Flux: (7.8 [+4.0, -3.1])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 4:
RA (J2000.0): 336.2146 = 22:24:51.50
Dec (J2000.0): +25.2635 = +25:15:48.7
Error: 8.9 arcsec (radius, 90% conf.)
Count-rate: (1.48 [+0.87, -0.64])e-3 ct s^-1
Distance: 474 arcsec from Swift/BAT-GUANO position.
Flux: (2.7 [+1.6, -1.2])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 5:
RA (J2000.0): 336.2452 = 22:24:58.84
Dec (J2000.0): +25.1872 = +25:11:14.1
Error: 5.7 arcsec (radius, 90% conf.)
Count-rate: (5.6 [+1.8, -1.5])e-3 ct s^-1
Distance: 182 arcsec from Swift/BAT-GUANO position.
Flux: (1.12 [+0.37, -0.30])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00021534.
This circular is an official product of the Swift-XRT team.
- GCN Circular #33136
Mohammad Odeh of Al-Khatim Observatory (AKO) operated by the International
Astronomical Center, in Abu Dhabi, UAE.
As a follow up for the GRB 221231A detected by Fermi/GBM (GCN 33129) and the
observations of the Swift/BAT-GUANO (Perri et al., GCN 33135), we observed
the localization of the five detected uncatalogued X-ray sources mentioned
in GCN 33135. Our observation was done with our 0.36m f/7.7 robotic
telescope on 01 January 2023 around 15:27 (UT), 17.7 hours after the GRB
trigger. We obtained multiple 180-sec exposures in Ic filter. We did not
detect any afterglow within the mentioned locations.
The following upper limit was calculated using Atlas catalogue as a
reference:
----------------------------------------------------------------------------
JD (mid), T_mid-T0(hrs), Exposure (sec), Filter, Lim_mag
----------------------------------------------------------------------------
2459946.143993, 17.7, 5 x 180 (stacked), Ic, > 18.8
----------------------------------------------------------------------------
These magnitudes are not corrected for galactic extinction.
- GCN Circular #33139
M. Perri (SSDC & INAF-OAR), A. Tohuvavohu (U. Toronto), D.N. Burrows
(PSU), J. D. Gropp (PSU), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), V. D'Elia (SSDC & INAF-OAR),
B. Sbarufatti (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf
of the Swift-XRT team:
Swift-XRT has conducted further observations of the field of the
Swift/BAT-GUANO-detected burst GRB 221231A. The observations now extend
from T0+32.7 ks to T0+120.0 ks.
Of the sources reported by Perri et al. (GCN Circ. 33135), "Source 2"
is fading with >3-sigma significance, and is therefore likely the GRB
afterglow. Using 4154 s of PC mode data and 2 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 = 336.25600, +25.12978
which is equivalent to:
RA (J2000): 22h 25m 01.44s
Dec(J2000): +25d 07' 47.2"
with an uncertainty of 3.0 arcsec (radius, 90% confidence). This
position is 34 arcsec from the Swift/BAT-GUANO position.
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.1 (+0.6, -0.5).
The results of the XRT-team automatic analysis of the likely afterglow
are at https://www.swift.ac.uk/ToO_GRBs/00021534/Source2.php.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021534.
This circular is an official product of the Swift-XRT team.
- GCN Circular #33146
S. Lesage (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 21:46:05 UT on 31 December 2022, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 221231A (trigger 694215970/221231907).
which was also detected by Swift BAT (A. Tohuvavohu et al. 2023, GCN 33132)
and Swift XRT GCN (M. Perri et al. 2023, 33139).
The Fermi GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 61 degrees.
The GBM light curve consists of a single emission episode with a duration
(T90)
of about 5 s (50-300 keV). The time-averaged spectrum
from T0-0.06 to T0+4.93 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.2 +/- 0.4 and the cutoff energy,
parameterized as Epeak, is 200 +/- 40 keV.
The event fluence (10-1000 keV) in this time interval is
(4.4 +/- 0.4)E-07 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0 s in the 10-1000 keV band is 3.9 +/- 0.2 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 #33149
Amit K. Ror, Rahul Gupta, S. B. Pandey, A. Aryan, A. Ghosh, Dimple, and K.
Misra (ARIES) report:
We observed the field of GRB 221231A detected by Fermi/GBM (2022, GCN
33129) using the 3.6m Devasthal Optical Telescope of ARIES Nainital. We
have taken multiple frames having an exposure time of 200 sec in the r
filter. We stacked the images after the alignment. We did not find any
evidence of an afterglow candidate inside the Swift XRT error circle (Perri
et al. 2023, GCNs 33135 and 33139). We obtained the limiting mag of ~ 21.7
mag at ~ 1.87 days post-detection. The non-detection of the optical
afterglow is consistent with Odeh 2023, GCN 32876.
The limiting magnitudes quoted are not corrected for the Galactic and host
extinction in the direction of the burst. Photometric calibration is
performed using the standard stars from the Pan-STARRS catalog.
This circular may be cited. 3.6m Devasthal Optical Telescope (DOT) is a
recently commissioned facility in the Northern Himalayan region of India
(long: 79 41 04E, lat: 29 21 40N, alt: 2540m) owned and operated by the
Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital (
https://www.aries.res.in). The authors of this GCN circular thankfully
acknowledge the consistent support from the staff members to run and
maintain the 3.6m DOT.
Previous IAU Circulars 
