- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Sun 27 Dec 20 15:14:31 UT
NOTICE_TYPE: Fermi-GBM Flight Position
RECORD_NUM: 48
TRIGGER_NUM: 630774852
GRB_RA: 106.183d {+07h 04m 44s} (J2000),
105.961d {+07h 03m 51s} (current),
106.706d {+07h 06m 50s} (1950)
GRB_DEC: -77.117d {-77d 07' 00"} (J2000),
-77.149d {-77d 08' 56"} (current),
-77.038d {-77d 02' 15"} (1950)
GRB_ERROR: 3.53 [deg radius, statistical plus systematic]
GRB_INTEN: 3528 [cnts/sec]
DATA_SIGNIF: 43.50 [sigma]
INTEG_TIME: 0.064 [sec]
GRB_DATE: 19210 TJD; 362 DOY; 20/12/27
GRB_TIME: 54847.41 SOD {15:14:07.41} UT
GRB_PHI: 290.00 [deg]
GRB_THETA: 150.00 [deg]
DATA_TIME_SCALE: 0.0640 [sec]
HARD_RATIO: 0.00
LOC_ALGORITHM: 3 (version number of)
MOST_LIKELY: 100% Below horizon
2nd_MOST_LIKELY: 0% n/a
DETECTORS: 0,0,0, 0,1,0, 0,0,1, 0,0,0, 0,0,
SUN_POSTN: 276.90d {+18h 27m 36s} -23.28d {-23d 17' 02"}
SUN_DIST: 79.42 [deg] Sun_angle= 11.4 [hr] (West of Sun)
MOON_POSTN: 66.36d {+04h 25m 27s} +20.45d {+20d 27' 08"}
MOON_DIST: 100.38 [deg]
MOON_ILLUM: 94 [%]
GAL_COORDS: 288.64,-25.66 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 252.00,-78.40 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201227635/quicklook/glg_lc_medres34_bn201227635.gif
COMMENTS: Fermi-GBM Flight-calculated Coordinates.
COMMENTS: This trigger occurred at longitude,latitude = 288.77,13.23 [deg].
COMMENTS: The LC_URL file will not be created until ~15 min after the trigger.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Sun 27 Dec 20 15:14:52 UT
NOTICE_TYPE: Fermi-GBM Ground Position
RECORD_NUM: 58
TRIGGER_NUM: 630774852
GRB_RA: 180.990d {+12h 03m 58s} (J2000),
181.267d {+12h 05m 04s} (current),
180.338d {+12h 01m 21s} (1950)
GRB_DEC: -73.880d {-73d 52' 47"} (J2000),
-73.997d {-73d 59' 48"} (current),
-73.602d {-73d 36' 05"} (1950)
GRB_ERROR: 1.24 [deg radius, statistical only]
DATA_SIGNIF: 77.90 [sigma]
DATA_INTERVAL: 0.064 [sec]
GRB_DATE: 19210 TJD; 362 DOY; 20/12/27
GRB_TIME: 54847.41 SOD {15:14:07.41} UT
GRB_PHI: 298.00 [deg]
GRB_THETA: 133.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 4173 (Gnd S/W Version number)
SUN_POSTN: 276.90d {+18h 27m 36s} -23.28d {-23d 17' 02"}
SUN_DIST: 69.20 [deg] Sun_angle= 6.4 [hr] (West of Sun)
MOON_POSTN: 66.37d {+04h 25m 28s} +20.45d {+20d 27' 11"}
MOON_DIST: 116.40 [deg]
MOON_ILLUM: 94 [%]
GAL_COORDS: 299.59,-11.32 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 234.31,-61.58 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201227635/quicklook/glg_lc_medres34_bn201227635.gif
POS_MAP_URL: http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_630774852.fits
COMMENTS: Fermi-GBM Ground-calculated Coordinates.
COMMENTS: Bright hard burst in the GBM.
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: Sun 27 Dec 20 15:23:28 UT
NOTICE_TYPE: Fermi-GBM Final Position
RECORD_NUM: 0
TRIGGER_NUM: 630774852
GRB_RA: 182.810d {+12h 11m 14s} (J2000),
183.099d {+12h 12m 24s} (current),
182.131d {+12h 08m 31s} (1950)
GRB_DEC: -73.020d {-73d 01' 11"} (J2000),
-73.137d {-73d 08' 11"} (current),
-72.742d {-72d 44' 30"} (1950)
GRB_ERROR: 1.90 [deg radius, statistical only]
GRB_DATE: 19210 TJD; 362 DOY; 20/12/27
GRB_TIME: 54847.41 SOD {15:14:07.41} UT
GRB_PHI: 298.00 [deg]
GRB_THETA: 132.00 [deg]
E_RANGE: 44.032 - 279.965 [keV]
LOC_ALGORITHM: 41731 (Gnd S/W Version number)
SUN_POSTN: 276.91d {+18h 27m 38s} -23.28d {-23d 17' 01"}
SUN_DIST: 68.86 [deg] Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN: 66.44d {+04h 25m 46s} +20.47d {+20d 28' 15"}
MOON_DIST: 117.17 [deg]
MOON_ILLUM: 94 [%]
GAL_COORDS: 299.96,-10.38 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 233.46,-60.67 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201227635/quicklook/glg_lc_medres34_bn201227635.gif
LOC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201227635/quicklook/glg_locplot_all_bn201227635.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 Short GRB.
- GCN NOTICE
TITLE: GCN/FERMI NOTICE
NOTICE_DATE: Sun 27 Dec 20 16:14:14 UT
NOTICE_TYPE: Fermi-GBM Final Position
RECORD_NUM: 0
TRIGGER_NUM: 630774852
GRB_RA: 182.790d {+12h 11m 10s} (J2000),
183.079d {+12h 12m 19s} (current),
182.111d {+12h 08m 27s} (1950)
GRB_DEC: -73.030d {-73d 01' 47"} (J2000),
-73.147d {-73d 08' 47"} (current),
-72.752d {-72d 45' 05"} (1950)
GRB_ERROR: 1.25 [deg radius, statistical only]
GRB_DATE: 19210 TJD; 362 DOY; 20/12/27
GRB_TIME: 54847.41 SOD {15:14:07.41} UT
GRB_PHI: 298.00 [deg]
GRB_THETA: 132.00 [deg]
E_RANGE: 50.000 - 300.000 [keV]
LOC_ALGORITHM: 415 (Gnd S/W Version number)
SUN_POSTN: 276.95d {+18h 27m 47s} -23.28d {-23d 16' 55"}
SUN_DIST: 68.88 [deg] Sun_angle= 6.3 [hr] (West of Sun)
MOON_POSTN: 66.89d {+04h 27m 32s} +20.58d {+20d 34' 33"}
MOON_DIST: 117.14 [deg]
MOON_ILLUM: 94 [%]
GAL_COORDS: 299.96,-10.39 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS: 233.47,-60.68 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201227635/quicklook/glg_lc_medres34_bn201227635.gif
LOC_URL: http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201227635/quicklook/glg_locplot_all_bn201227635.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 has human-in-the-loop processing.
- GCN Circular #29179
A. Ursi (INAF/IAPS), F. Verrecchia, C. Pittori (SSDC, and INAF/OAR),
F. Longo (Univ. Trieste and INFN Trieste), M. Tavani (INAF/IAPS, and
Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y.Evangelista,
G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A. Bulgarelli,
V. Fioretti, F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi
(INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois
(INAF/OA-Cagliari), I. Donnarumma (ASI), A. Giuliani (INAF/IASF-Mi),
report on behalf of the AGILE Team:
The AGILE Mini-CALorimeter (MCAL) detected a short burst at
T0 = 2020-12-27 15:14:07.40 +/- 0.01 s (UTC) detected also by
Fermi/GBM (trigger 630774852).
The event lasted about 0.10 s and released a total number of ~480 counts
in the detector (in the 0.4-100 MeV energy range),
above an average background rate of 676 counts / s.
The light curve shows a single sharp peak and can be found at
http://www.agilescienceapp.it/notices/GRB_071058_536166847.405605.png.
The AGILE-MCAL detector is a CsI detector with a 4 pi FoV,
sensitive in the energy range 0.4-100 MeV.
Additional analysis of AGILE data is in progress.
Automatic MCAL GRB alert Notices can be found at:
https://gcn.gsfc.nasa.gov/agile_mcal.html.
- GCN Circular #29182
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,
K. Hurley, on behalf of the IPN,
A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi GBM team,
A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, and
A. Ursi, N. Parmiggiani, F. Verrecchia, A. Bulgarelli,
A. Trois, M. Marisaldi, C. Pittori, M. Tavani, Y. Evangelista,
I. Donnarumma, M. Cardillo, G. Piano, G. Minervini, A. Argan,
F. Lucarelli, A. Zoli, V. Fioretti, F. Fuschino, M. Pilia,
F. Longo, A. Giuliani on behalf of the AGILE team, report:
The short-duration, very bright GRB 201227A
(AGILE detection: Ursi et al., GCN Circ. 29179)
has been detected by Fermi (GBM trigger 630774852), Konus-Wind,
INTEGRAL (SPI-ACS), AGILE (MCAL), and Swift (BAT), so far,
at about 54847 s UT (15:14:07).
The burst was outside the coded field of view of the BAT.
We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
170.121 (11h 20m 29s) -73.613 (-73d 36' 48")
Corners:
171.971 (11h 27m 53s) -73.140 (-73d 08' 22")
171.755 (11h 27m 01s) -73.060 (-73d 03' 36")
168.169 (11h 12m 41s) -74.071 (-74d 04' 16")
168.379 (11h 13m 31s) -74.155 (-74d 09' 17")
---------------------------------------------
The error box area is 517 sq. arcmin, and its maximum
dimension is 1.45 deg (the minimum one is 6 arcmin).
The Sun distance was 72 deg.
This box may be improved.
The Swift ToO has been submitted.
A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB201227_T54847/IPN/
The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.
- GCN Circular #29184
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the IPN GRB 201227A.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021409
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 IPN 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 #29185
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a series of observations, tiled on the sky, of the
IPN GRB 201227A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00096
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the IPN event is high: 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 #29187
S. Xiao, C. Cai, Y. F. Du, Y. G. Zheng, Q. Luo, Q. B. Yi,
Y. Huang, C. K. Li, G. Li, X. B. Li, J. Y. Liao, S. L. Xiong,
C. Z. Liu, X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang,
Y. F. Zhang, X. F. Lu, C. L. Zou (IHEP), Y. J. Jin,
Z. Zhang (THU), T. P. Li (IHEP/THU), F. J. Lu, L. M. Song,
M. Wu, Y. P. Xu, S. N. Zhang (IHEP),
report on behalf of the Insight-HXMT team:
At 2020-12-27T15:14:07.400 (T0), Insight-HXMT/HE detected
GRB 201227A (trigger ID: HEB201227634) in a routine search of the data,
which also triggered Fermi/GBM (trigger 630774852) and
AGILE Mini-CALorimeter (GCN#29179).
The Insight-HXMT/HE light curve mainly consists of multiple
pulses with a duration (T90) of 0.098 s measured from T0-0.03 s.
The 1-ms peak rate, measured from T0+0.024 s, is 52740 cnts/sec.
The total counts from this burst is 1612 counts.
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB201227634_lc.jpg
The HE light curves have not been corrected for data saturation
caused by the extreme brightness of this burst in HE.
All measurements above are made with the CsI detectors operating in the
regular mode with the energy range of about 80-800 keV (deposited energy).
Only gamma-rays with energy greater than about 200 keV can penetrate
the spacecraft and leave signals in the CsI detectors installed inside
of the telescope.
Insight-HXMT is the first Chinese space X-ray telescope, which was
funded jointly by the China National Space Administration (CNSA) and
the Chinese Academy of Sciences (CAS).
More information about it could be found at:
http://www.hxmt.org.
- GCN Circular #29196
D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks,
M. Ulanov, A. Tsvetkova, A. Lysenko, A. Ridnaia, and T. Cline
on behalf of the Konus-Wind team, report:
The short-duration, very bright GRB 201227A
(AGILE detection: Ursi et al., GCN Circ. 29179;
IPN triangulation: Svinkin et al., GCN Circ. 29182;
Insight-HXMT/HE detection: Xiao et al., GCN Circ. 29187)
triggered Konus-Wind at T0=54846.705 s UT (15:14:06.705).
The burst light curve shows a multipeaked structure
which starts at ~T0-28 ms and has a total duration of ~106 ms.
The emission is seen up to ~4 MeV.
The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB201227_T54846/
As observed by Konus-Wind, the burst
had a fluence of 4.30(-0.52,+0.54)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0,
of 1.05(-0.18,+0.18)x10^-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).
The time-averaged spectrum of the burst
(measured from T0 to T0+0.064 s)
is best fit in the 20 keV - 4 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -0.17(-0.18,+0.21)
and Ep = 870(-130,+151) keV (chi2 = 17/19 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 = 17/18 dof).
All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.
- GCN Circular #29202
V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), A. Tohuvavohu (U.
Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), A. Melandri (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 IPN-detected
burst GRB 201227A (Ursi et al. GCN Circ. 29179) in a series of
observations tiled on the sky. The total exposure time is 7.5 ks,
distributed over 4 tiles; the maximum exposure at a single sky location
was 5.3 ks. The data were collected between T0+51.6 ks and T0+80.7 ks,
and are entirely in Photon Counting (PC) mode.
Four 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. Details of these sources are given below:
Source 1:
RA (J2000.0): 170.6083 = 11:22:25.99
Dec (J2000.0): -73.4880 = -73:29:16.9
Error: 7.4 arcsec (radius, 90% conf.)
Count-rate: (4.4 [+1.7, -1.4])e-3 ct s^-1
Distance: 670 arcsec from IPN position.
Flux: (9.0 [+3.5, -2.8])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 2:
RA (J2000.0): 170.6190 = 11:22:28.57
Dec (J2000.0): -73.4798 = -73:28:47.2
Error: 4.8 arcsec (radius, 90% conf.)
Count-rate: (3.6 [+1.6, -1.3])e-3 ct s^-1
Distance: 698 arcsec from IPN position.
Flux: (1.34 [+0.60, -0.47])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
Source 3:
RA (J2000.0): 169.8508 = 11:19:24.19
Dec (J2000.0): -73.5866 = -73:35:11.9
Error: 5.6 arcsec (radius, 90% conf.)
Count-rate: (2.8 [+1.4, -1.1])e-3 ct s^-1
Distance: 290 arcsec from IPN position.
Source 4:
RA (J2000.0): 171.2953 = 11:25:10.87
Dec (J2000.0): -73.6326 = -73:37:57.4
Error: 4.4 arcsec (radius, 90% conf.)
Count-rate: (4.2 [+2.6, -1.9])e-3 ct s^-1
Distance: 1194 arcsec from IPN position.
The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00096.
This circular is an official product of the Swift-XRT team.
- GCN Circular #29206
S. Lesage, P. Veres, C. Meegan (all UAH), J. Mangan (UCD) and R. Dunwoody
(UCD)
report on behalf of the Fermi GBM Team:
"At 15:14:07.41 UT on 23 December 2020, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 201227A (trigger 630774852 / 201227635),
which was also detected by Konus-Wind (Svinkin et al. GCN 29196),
Insight-HXMT (Xiao et al., GCN 29187),
AGILE (Ursi et al., GCN 29179) and IPN (Svinkin et al., GCN 29182).
The GBM on-ground location is consistent with the IPN position.
The angle from the Fermi LAT boresight at the GBM trigger time is 135
degrees.
The GBM light curve consists of a short bright pulse
with a duration (T90) of about 0.1 s (50-300 keV).
The time-averaged spectrum from T0-64 ms to T0+128 ms is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.47 +/- 0.07 and
the cutoff energy, parameterized as Epeak, is 1076 +/- 96 keV.
The event fluence (10-1000 keV) in this time interval is
(3.6 +/- 0.1)E-6 erg/cm^2. The 64-ms peak photon flux measured
starting from T0 in the 10-1000 keV band
is 100 +/- 5 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 #29207
L. Izzo (DARK/NBI), P. D'Avanzo (INAF-OAB), E. Brocato (INAF-OAA/INAF-OAR) report on behalf of GRAWITA:
We observed the field of the short GRB 201227A (Fermi/GBM trigger 630774852; Ursi et al., GCN Circ. 29179;
Svinkin et al., GCN Circ. 29182; Xiao et al., GCN Circ. 29187; Svinkin et al., GCN Circ. 29196; Lesage et al.,
GCN Circ. 29206) with the VLT Survey Telescope (VST) equipped with OmegaCAM (1 square degree FOV;
Proposal ID ESO 0106.D-0343(A)).
We obtained one epoch of observations with the r filter on 2020-12-28 between 07:10:07 UT and 07:32:12 UT
(i.e. between 15.93 and 16.30 hours after the burst t0).
The observations cover 2 square degrees enclosing ~ 100% of the IPN localization box (Svinkin et al., GCN Circ. 29182).
Each one square degree pointing is the coaddition of five dithered exposures for a total exposure time of 300 seconds per
pointing.
From a preliminary analysis, we find no clear optical counterpart of GRB 201227A inside the IPN error box down to a 3sigma
limiting magnitude of r ~ 22 (AB, calibrated against the SkyMapper survey).
In particular, we do not find optical countepart candidates at the position of the four Swift/XRT sources reported by D'Elia et al.
(GCN Circ. 29202) nor at the position of the only galaxy listed in the GLADE catalogue found inside the IPN error box (galaxy
coordinates (J2000): RA, Dec = 168.85910, -73.94917, redshift z = 0.1379; Dalya et al., 2018, MNRAS, 479, 2347).
Further analysis is in progress.
We acknowledge excellent support from the ESO observing staff at Paranal, in particular Bin Yang.
- GCN Circular #29208
S. Belkin (IKI), A. Pozanenko (IKI), M. Krugov (FAI), P. Minaev (IKI)
report on behalf of GRB IKI FuN collaboration:
We observed the field of XRT 1-3 sources (D'Elia et al., GCN 29202)
(hereafter X1,X2,X3) found in IPN localization area (Svinkin et al.,
GCN 29182) of GRB 201227A (Ursi et al., GCN 29179; Xiao et al., GCN
29187; Svinkin et al., GCN 29196; Lesage et al., GCN 29206) with
Chilescope RC-1000 starting on 2020-12-29 (UT) 04:02:05 in r'-filter.
The X3 source was observed by one 300 s exposure, and the filed of X1,X2
was observed by 3*300 s exposure. The limiting magnitude of single
exposure of X3 and the stacked 3*300 s exposure is about r'=20.9.
There are two optical sources close or on the edge of the XRT error
circle localization of X3. Both sources are present in USNO-B1.0 and our
photometry of the sources show no excess in brightness in comparison
with any R-mag of USNO-B1.0.
Also there are two optical sources close or on the edge of the XRT error
circle localization of X1. Both source are also present in USNO-B1.0 and
our photometry of the sources show no excess in brightness in comparison
with any R-mag of USNO-B1.0.
At the edges of X2 error circle we found two sources which not presented
in USNO-B1.0. The coordinates of the first one (X2_O1) is RA(J2000)=11h
22m 29.34s, Dec(J2000)=-73d 28’ 44.9’’. The photometry of the source is
r'= 20.50 +/-0.29 and the source is barely visible in DSS2 plate. The
coordinates of second one (X2_02) is RA(J2000)=11h 22m 27.94s,
Dec(J2000)=-73d 28’ 50.6’’. The photometry of the source is r'= 20.52
+/-0.29 and the source is not presented in DSS2 plate. We may suggest
the optical object X2_02 could be a counterpart of GRB 201227A.
The photometry is based on nearby stars from the APASS_DR8 and still
preliminary
RA DEC r
11:19:31.40904 -73:35:47.6880 14.090
11:19:44.89128 -73:34:49.6092 15.180
11:19:36.65304 -73:36:30.2112 15.307
Taking into account that early more deep observations of the IPN field
by GRAWITA VST-ESO PARANAL (Izzo et al., GCN 29207) does no show any
counterpart we may suggest the X2_O2 source (RA(J2000)=11h 22m 27.936s,
Dec(J2000)=-73d 28’ 50.55’’) is a possible optical counterpart or
kilonova of GRB 201227A.
- GCN Circular #29276
M. Marisaldi (University of Bergen), A. Mezentsev (University of Bergen),
N. Østgaard (University of Bergen), V. Reglero (University of Valencia)
and T. Neubert (DTU Space) report on behalf of the ASIM Team:
At 15:14:07.380 UT on 27 December 2020, the Atmosphere-Space Interactions Monitor (ASIM)
mission triggered on the very short and bright GRB 201227A
(AGILE detection: Ursi et al., GCN Circ. 29179; IPN triangulation: Svinkin et al., GCN Circ. 29182;
Swift observations: Evans, GCN Circ. 29184; Evans, GCN Circ. 29185; D’Elia et al., GCN Circ. 29202;
Insight-HXMT/HE detection: Xiao et al., GCN Circ. 29187; Konus-Wind observation: Svinkin et al., GCN Circ. 29196;
Fermi GBM observation: Lesage et al., GCN Circ. 29206; GRAWITA VST observation: Izzo et al., GCN Circ. 29207
Chilescope observation: Belkin et al., GCN Circ. 29208)
Photon by photon data with <1 microsecond time resolution have been
collected for a time interval of two seconds centered at the trigger time.
As seen by the Modular X- and Gamma-Ray Sensor (MXGS) onboard ASIM
the burst consists of a single emission episode about 60 ms in duration, with evidence of time variability.
The emission is detected in the MXGS High Energy Detector (HED),
sensitive in the range 0.3 to >30 MeV.
Significant emission is observed up to about 3 MeV.
The MXGS Low Energy Detector (LED), sensitive in the range 0.05 to 0.4 MeV,
was not active at trigger time.
ASIM is an ESA mission onboard the International Space Station dedicated to the
observation of Terrestrial Gamma-ray Flashes (TGFs) and Transient Luminous Events (TLEs)
operative since June 2018 (Neubert et al., Space Sci Rev (2019) 215:26
https://doi.org/10.1007/s11214-019-0592-z ).
The payload includes the Modular X- and Gamma-Ray Sensor (MXGS)
(Østgaard et al., Space Sci Rev (2019) 215:23 https://doi.org/10.1007/s11214-018-0573-7 ),
and the the Modular Multispectral Imaging Array (MMIA)
(Chanrion et al., Space Sci Rev (2019) 215:28 https://doi.org/10.1007/s11214-019-0593-y ).
The ASIM Science Data Centre (ASDC) website is https://asdc.space.dtu.dk/
- GCN Circular #29281
S. Belkin (IKI), A. Pozanenko (IKI), P. Minaev (IKI), M. Krugov (FAI)
report on behalf of GRB IKI FuN collaboration:
We continued observations of the field of XRT #2 sources (D'Elia et al.,
GCN 29202) (hereafter X2) found in IPN localization area (Svinkin et
al., GCN 29182) of GRB 201227A (Ursi et al., GCN 29179; Xiao et al., GCN
29187; Svinkin et al., GCN 29196; Lesage et al., GCN 29206; Marisaldi et
al., GCN 29276) with Chilescope RC-1000 on 2021-01-01 and 2021-01-08 in
r'-filter.
The X2_O2 object found in previous observation on 2020-12-29 at r'(AB)=
20.5 (Belkin et al., GCN 29208; see also Izzo et al., GCN 29207) is not
detected on 2021-01-01 with an upper limit of r'(AB) > 20.6 and barely
detected on 2021-01-08 at r'(AB)=22.6. Now we confirm the variability of
the object of X2_O2 and suggest the optical object X2_02 could be a
counterpart of GRB 201227A. In the last image on 2021-01-08, the object
X2_O2 could be the host galaxy. A finding chart of the X2_O2 can be found in
http://grb.rssi.ru/GRB201227A/GRB201227A_r_FC_201229_2100108.png
Preliminary photometry of the X2_O2 is following
Date UT start t-T0 Filter Exp. OT(AB) Err. UL(AB) FWHM
(mid, days) (s)
2021-01-01 05:57:21 4.63072 r' 5*600 n/d n/d 20.6 1.5"
2021-01-08 04:15:45 11.5636 r' 3*1200 22.6 0.4 22.5 1.4"
The photometry is based on nearby stars from the APASS_DR8
RA DEC r
11:19:31.40904 -73:35:47.6880 14.090
11:19:44.89128 -73:34:49.6092 15.180
11:19:36.65304 -73:36:30.2112 15.307
In addition we investigated a position of the GRB 201227A on the EHD
diagram (see Minaev et al., MNRAS, 492, 1919, 2020). The position of
GRB 201227A based on Konus-Wind data (Svinkin et al., GCN Circ. 29196)
can be found in
http://grb.rssi.ru/GRB201227A/GRB201227A_EH_T90i.png
We can exclude the GRB 201227A as a giant flare event of SGR since there
is no nearby galaxies in the IPN error box. We can identify the GRB
201227A as short GRB at a redshift of z > 0.05.
Previous IAU Circulars 
