GRB 201227A
GCN Circular 29281
Subject
GRB 201227A: continued Chilescope confirmation of variability of possible optical counterpart, redshift estimating
Date
2021-01-08T16:20:33Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
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.
GCN Circular 29276
Subject
GRB 201227A: ASIM observation
Date
2021-01-07T14:29:38Z (5 years ago)
From
Martino Marisaldi at U of Bergen, Norway <martino.marisaldi@uib.no>
M. Marisaldi (University of Bergen), A. Mezentsev (University of Bergen),
N. ��stgaard (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 <https://doi.org/10.1007/s11214-019-0592-z> ).
The payload includes the Modular X- and Gamma-Ray Sensor (MXGS)
(��stgaard et al., Space Sci Rev (2019) 215:23 https://doi.org/10.1007/s11214-018-0573-7 <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 <https://doi.org/10.1007/s11214-019-0593-y> ).
The ASIM Science Data Centre (ASDC) website is https://asdc.space.dtu.dk/ <https://asdc.space.dtu.dk/>
GCN Circular 29208
Subject
GRB 201227A: Chilescope optical observations, possible optical counterpart
Date
2020-12-30T21:14:02Z (5 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>