GRB 210120A
GCN Circular 29334
Subject
GRB 210120A: Fermi GBM Final Real-time Localization
Date
2021-01-20T07:21:03Z (4 years ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
The Fermi GBM team reports the detection of a likely LONG GRB
At 07:10:44 UT on 20 Jan 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210120A (trigger 632819449.704302 / 210120299).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 163.4, Dec = 17.1 (J2000 degrees, equivalent to J2000 10h 53m, 17d 06'), with a statistical uncertainty of 3.8 degrees.
The angle from the Fermi LAT boresight is 83.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210120299/quicklook/glg_skymap_all_bn210120299.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210120299/quicklook/glg_healpix_all_bn210120299.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210120299/quicklook/glg_lc_medres34_bn210120299.gif
GCN Circular 29335
Subject
GRB 210120A: BALROG localization (Fermi Trigger 632819449 / GRB 210120299)
Date
2021-01-20T07:43:15Z (4 years ago)
From
Jochen Greiner at MPE,Garching <jcg@mpe.mpg.de>
B. Biltzinger, F. Kunzweiler, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
632819449 at 07:10:44 on 20 Jan. 2021 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).
The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 163.5+/-2.8 deg
Decl.(2000.0) = 17.0+/-2.2 deg
We estimate an additional systematic error of 1 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB210120299/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB210120299/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB210120299/json
GCN Circular 29336
Subject
Fermi GRB 210120A: Global MASTER-Net observations report
Date
2021-01-20T09:00:10Z (4 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin,
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov, D. Cheryasov
(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. Gres, N.M. Budnev, O.Ershova
(Irkutsk State University, API),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko
(Blagoveschensk Educational State University)
MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 210120A ( Fermi GBM team, GCN 29334) errorbox 80 sec after notice time and 143 sec after trigger time at 2021-01-20 07:13:07 UT, with upper limit up to 19.5 mag. The observations began at zenith distance = 50 deg. The sun altitude is -27.8 deg.
The galactic latitude b = 61 deg., longitude l = 228 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1529824
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
158 | 2021-01-20 07:13:07 | MASTER-OAFA | (11h 02m 27.64s , +18d 11m 39.0s) | C | 30 | 18.3 |
214 | 2021-01-20 07:13:58 | MASTER-OAFA | (11h 02m 27.67s , +18d 10m 13.7s) | C | 40 | 18.4 |
279 | 2021-01-20 07:14:58 | MASTER-OAFA | (11h 02m 30.93s , +18d 11m 51.7s) | C | 50 | 19.0 |
353 | 2021-01-20 07:16:07 | MASTER-OAFA | (11h 02m 25.55s , +18d 10m 58.1s) | C | 60 | 18.8 |
646 | 2021-01-20 07:20:30 | MASTER-OAFA | (10h 52m 05.03s , +16d 29m 39.0s) | C | 120 | 19.2 |
795 | 2021-01-20 07:22:49 | MASTER-OAFA | (10h 52m 11.15s , +16d 29m 48.7s) | C | 140 | 19.4 |
974 | 2021-01-20 07:25:29 | MASTER-OAFA | (10h 52m 07.89s , +16d 31m 35.3s) | C | 180 | 19.5 |
1174 | 2021-01-20 07:28:48 | MASTER-OAFA | (10h 52m 07.90s , +16d 30m 04.6s) | C | 180 | 19.4 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 29338
Subject
GECAM In-Flight Trigger of GRB 210120A
Date
2021-01-20T14:43:51Z (4 years ago)
From
Shaolin Xiong at IHEP <xiongsl@ihep.ac.cn>
Z. H. An, C. Cai, G. Chen, W. Chen, M. Gao, M. Y. Ge, K. Gong, D. Y. Guo,
J. J. He, Y. Huang, B. Li, C. Li, C. Y. Li, J. H. Li, M. S. Li, Q. X. Li,
X. B. Li, X. Q. Li, Y. G. Li, X. H. Liang, J. Y. Liao, J. C. Liu, X. J. Liu,
Y. Q. Liu, F. J. Lu, Q. Luo, X. Ma, G. Ou, W. X. Peng, R. Qiao, J. Y. Shi,
D. L. Shi, L. M. Song, X. Y. Song, G. X. Sun, X. L. Sun, Y. L. Tuo,
J. Z. Wang, C. W. Wang, P. Wang, W. S. Wang, X. Y. Wen, S. Xiao,
S. L. Xiong, Y. B. Xu, Y. P. Xu, W. C. Xue, S. Yang, M. Yao, Q. B. Yi,
K. Zhang, P. Zhang, D. L. Zhang, F. Zhang, H. M. Zhang, S. N. Zhang,
Y. Q. Zhang, Z. Zhang, S. Y. Zhao, X. Y. Zhao, Y. Zhao, C. Zheng,
S. J. Zheng (IHEP), L. Chang, W. W. Chen, Y. M. Chen, L. Dong, X. B. Han,
J. Huang, J. Huang, C. Y. Ji, Y. C. Ji, F. Li, M. Y. Li, Z. D. Li,
Y. F. Lu, Y. Pang, J. L. Qi, J. G. Rong, Q. Q. Wang, Z. Wang, Y. Yang,
J. P. Yu, S. M. Yu, K. K. Zhang, D. K. Zhou (IAMCAS), M. Bai, T. Hu, Z. Ji,
Y. R. Liu, J. Su, C. X. Tian, J. Z. Tong, H. Y. Wu, Q. S. Yu, J. Zhong,
Z. M. Zou (NSSC), X. X. Feng (AIR),
(The GECAM Mission Team) report:
During the commissioning phase, one satellite of GECAM mission, GECAM-B,
was triggered by a long GRB 210120A at 2021-01-20T07:10:48.550 (T0),
which was also observed by Fermi/GBM (GCN #29334, 29335).
This burst was triggered, localized and classified as unknown source by
the GECAM In-Flight Trigger and Localization Software and
then its alert data was promptly downlinked to the ground through the
short message service of BeiDou Navigation Satellite System (BDS).
The time latency of the first BeiDou message (including in-flight trigger
and location results) relative to the trigger time is about 60 seconds.
All other messages (including light curves data) for this trigger arrived
within about 10 minutes.
We made the quick-look light curve and the on-ground localization using the
alert data. The quick-look light curve shows that this burst mainly consists
of a single peak with a duration of about 20 s.
Although the in-flight calibration of energy response and localization
has not been finalized yet, the quick-look location is generally consistent
with the position given by Fermi/GBM within the error.
As the detailed science data are downloaded, all analyses including
localization would be further improved.
The GECAM quick-look light curve could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/utn210120_071048_GECAMb.png
The GECAM quick-look location (preliminary) could be found here:
http://twiki.ihep.ac.cn/pub/GECAM/GRBList/utn210120_071048_GECAMb_Localization.png
Please note that all GECAM results here are preliminary. The final analysis
will be published in journal papers or GECAM online catalog.
This is the first GECAM GRB which was triggered and localized in-flight
with alert data promptly downlinked to ground successfully.
Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in
Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time),
which was funded by the Chinese Academy of Sciences (CAS).
GCN Circular 29339
Subject
GRB 210120A: MASTER OT (possibly) discovery
Date
2021-01-20T20:41:29Z (4 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E.Gorbovskoy,N.Tiurina,P.Balanutsa,F.Balakin, V.Vladimirov, A.Kuznetsov,K.Zhirkov,D. Vlasenko, I.Gorbunov, D.Zimnukhov,
V.Senik, A.Chasovnikov,A.Pozdnyakov,V.Topolev, D.Cheryasov(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico FelixAguilar OAFA),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley (South African Astronomical Observatory),
O.A. Gres, N.M. Budnev (Irkutsk State University, API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov, Yu. Sergienko (Blagoveschensk Educational StateUniversity)
MASTER-OAFA robotic telescope (MASTER-Net: http://observ.pereplet.ru Lipunov et al.,2010,Advances in Astronomy,2010,30L)
automatically was pointed (Lipunov et al. GCN 29336)
to Fermi GRB210120A (Ttrigger=07:10:44UT, Fermi GCN 29334, BALROG localization Biltzinger et al. GCN 29335,
Barthelmy https://gcn.gsfc.nasa.gov/other/210120A.gcn3 )
80s after notice time (143s after trigger time) at 2021-01-20 07:13:07UT
At first images MASTER auto-detection system found fast changing optical transient
MASTER OT J105242.66+152355.0 / AT2021axc
at (RA, Dec) = 10h 52m 42.66s +15d 23m 55.0s at 2021-01-20 07:20:30UT
with unfiltered m_OT=18.6 at the beginning stage.
The OT is seen at several images. There is no any sources at this place in
MASTER database since 2004.
The nearest source in VIZIER is SDSS galaxy in 4.9" with rmag(as most
closest to MASTER unfiltered)=22.217 (22.088 in PanSTARRS)
The reduction will be continued.
This message may be cited.
GCN Circular 29341
Subject
GRB 210120A(MASTER OT J105242.66+152355.0 / AT2021axc): Mondy optical observations
Date
2021-01-21T09:08:59Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
S. Belkin (IKI), A. Pozanenko (IKI), N. Pankov (HSE), E. Klunko (ISTP)
report on behalf of GRB IKI FuN:
We observed the MASTER OT J105242.66+152355.0 / AT2021axc (Lipunov et
al., GCN 29339) in the field of Fermi GRB 210120A (Fermi GBM Team, GCN
29334; Biltzinger et al. GCN 29335) with AZT-33IK telescope of Sayan
observatory (Mondy) starting on 2021-01-20 (UT) 20:57:41. The candidate
in optical afterglow (Lipunov et al., GCN 29339) is well detected in our
R-filter stacked image at R = 22.14 +/- 0.27 with 3 sigma upper limit of
the field for point-like source R=22.3. We confirm fading nature of the
transient and support it for afterglow candidate of GRB 210112A.
Preliminary photometry of the optical transient in the stacked image is
following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2021-01-20 20:57:41 0.59510 R 30*120 22.14 0.27 22.3
The photometry is based on the nearby USNO-B1.0 stars
USNO-B1.0_id R2
1053-0195054 16.13
1053-0195003 18.57
GCN Circular 29345
Subject
GRB 210120A : 1.3m DFOT optical observations
Date
2021-01-22T20:35:52Z (4 years ago)
From
Dimple Panchal at ARIES, India <dimplepanchal96@gmail.com>
Dimple (ARIES), A. Ghosh (ARIES), R. Gupta (ARIES), A. Kumar (ARIES), K.
Misra (ARIES), S.B. Pandey (ARIES) report:
We carried out the follow-up observations of the MASTER OT
J105242.66+152355.0 / AT2021axc (Lipunov et al., GCN #29339) in the field
of Fermi GRB 210120A (Fermi GBM Team, GCN
29334; Biltzinger et al., GCN #29335) with 1.3m Devasthal Fast Optical
Telescope (DFOT) at Devasthal observatory of Aryabhatta Research Institute
of observational sciencES (ARIES), India. The observations started on
2021-01-21 at 20:51:55 in R-band. We observed a set of 18 images with an
exposure time of 300 seconds each, centered at 1.5937 days after the burst.
We clearly detect the optical afterglow candidate reported by Lipunov
et al., GCN #29339 in the stacked image with a magnitude of 22.60+-0.16. The
object is fading with time (S. Belkin et al. GCN #29341; Lipunov et al.,
GCN #29339) which supports it as an afterglow candidate for GRB 210120A.
The magnitude is not corrected for the Galactic extinction in the direction
of the burst. The photometric calibration is performed using the standard
stars from the USNO-B1.0 catalog.
GCN Circular 29361
Subject
GRB 210120A: Fermi GBM detection
Date
2021-01-27T01:39:51Z (4 years ago)
From
Stephen Lesage at Fermi-GBM Team <sjl0014@uah.edu>
S. Lesage (UAH), R. Dunwoody (UCD), J. Mangan (UCD), C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 07:10:44.70 UT on 20 January 2021, the Fermi Gamma-Ray Burst Monitor
(GBM)
triggered and located GRB 210120A (trigger 632819449 / 210120.299),
the optical counterpart for which was detected by MASTER (Lipunov et al.
2021,
GCN 29339) and confirmed (Pozanenko et al. 2021, GCN 29341; Dimple et al.
2021,
GCN 29345). The GBM Fermi GBM Final Real-time Localization (GCN 29334) is
consistent
with the MASTER OT follow-up observations.
The angle from the Fermi LAT boresight at the GBM trigger time is 82
degrees.
The GBM light curve consists of a single peak
with a duration (T90) of about 22.2 s (50-300 keV).
The time-averaged spectrum from T0-0.32 s to T0+22.21 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.62 +/- 0.12 and
the cutoff energy, parameterized as Epeak, is 94 +/- 6 keV
The event fluence (10-1000 keV) in this time interval is
(2.9 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+ 2.6 s in the 10-1000 keV band
is 3.6 +/- 0.2 ph/s/cm^2.
A Band function fits the spectrum equally well
with Epeak= 95 +/- 6 keV, alpha = -0.63 +/- 0.12 and beta = -29 +/- 6E12.
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/"