GRB 210211A
GCN Circular 29470
Subject
GRB 210211A: Fermi GBM Final Real-time Localization
Date
2021-02-11T08:50:50Z (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 08:43:18 UT on 11 Feb 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 210211A (trigger 634725803.658592 / 210211363).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 283.8, Dec = -55.1 (J2000 degrees, equivalent to J2000 18h 55m, -55d 06'), with a statistical uncertainty of 11.8 degrees.
The angle from the Fermi LAT boresight is 45.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210211363/quicklook/glg_skymap_all_bn210211363.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/bn210211363/quicklook/glg_healpix_all_bn210211363.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn210211363/quicklook/glg_lc_medres34_bn210211363.gif
GCN Circular 29472
Subject
GRB 210211A: Swift detection of a burst
Date
2021-02-11T09:00:56Z (4 years ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
E. Troja (NASA/GSFC/UMCP), P. A. Evans (U Leicester),
H. A. Krimm (NSF), K. L. Page (U Leicester), B. Sbarufatti (PSU) and
M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 08:43:18 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 210211A (trigger=1032024). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 269.433, -46.299 which is
RA(J2000) = 17h 57m 44s
Dec(J2000) = -46d 17' 57"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a double-peaked
structure with a duration of about 10 sec. The peak count rate
was ~2500 counts/sec (15-350 keV), at ~4 sec after the trigger.
The XRT began observing the field at 08:44:32.2 UT, 73.9 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 269.4374, -46.2660
which is equivalent to:
RA(J2000) = 17h 57m 44.99s
Dec(J2000) = -46d 15' 57.7"
with an uncertainty of 3.4 arcseconds (radius, 90% containment). This
location is 119 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. We cannot determine whether the source
is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.24 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 8.7
(+9.04/-6.57) x 10^21 cm^-2 (90% confidence).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 77 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 none of
the XRT error circle. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. Because of the density of
catalogued stars, further analysis is required to report an upper limit for any
afterglow in the region. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.126.
Burst Advocate for this burst is E. Troja (eleonora.troja AT nasa.gov).
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 Circular 29474
Subject
GRB 210211A: REM optical/NIR afterglow detection
Date
2021-02-11T11:19:34Z (4 years ago)
From
Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>
P. D'Avanzo, S. Covino, D. Fugazza, A. Melandri (INAF-OAB) on behalf of the REM team, report:
We observed the field of GRB 210211A (Troja et al., GCN Circ. 29472) with the REM 60cm robotic
telescope located at the ESO premise of La Silla (Chile). The observations were performed starting
on 2021 February 11 at 08:44:54 UT (i.e. 96 seconds after the burst) and were carried in the g, r, i, z, H
bands simultaneously.
From a preliminary analysis of the first set of images, obtained at a mid time of t-t0 = 101 s we detect in
all filters an uncatalogued object at the following position:
RA (J2000), Dec (J2000) = 17:57:45.67, -46:16:01.8 (+/- 0.5")
with a magnitude r = 16.9 +/- 0.1 (AB; calibrated against the APASS catalogue). This source is found about
1.5 magnitudes fainter in a subsequent set of images obtained at t-t0 = 204 s.
The source position lies about 8" outside the current available XRT error circle (https://www.swift.ac.uk/xrt_positions/).
However, the observed brightness and rapid fading suggests that it is the optical/NIR afterglow of GRB 210211A.
We also note the presence of an optical/NIR source inside the XRT error circle whose magnitude does not show significant
variation in our dataset.
Further analysis is in progress.
GCN Circular 29477
Subject
GRB 210211A: MASTER optical observation of REM OT
Date
2021-02-11T12:56:02Z (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 (Blagoveschensk Educational StateUniversity)
MASTER-OAFA robotic telescope (MASTER-Net: http://observ.pereplet.ru Lipunov et al.,2010,Advances in Astronomy,2010,30L)
automatically started (Lipunov et al. GCN 29471)
Swift GRB 200211A (Troja et al. GCN 29472,Ttrigger=08:43:18UT)
at 2021-02-11 08:44:02UT with 10s exposition.
At the second (10s exp), third (20s exp) and fourth images we see OT,
discovered by REM (D'Avanzo et al. GCN29474)
The reduction of MASTER wide field and very wide field cameras images will be continued.
This message may be cited.
GCN Circular 29478
Subject
GRB 210211A: Enhanced Swift-XRT position
Date
2021-02-11T13:47:05Z (4 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester)
report on behalf of the Swift-XRT team.
Using 481 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 210211A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 269.43976, -46.26729 which is equivalent
to:
RA (J2000): 17h 57m 45.54s
Dec (J2000): -46d 16' 02.3"
with an uncertainty of 2.4 arcsec (radius, 90% confidence).
This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).
This circular was automatically generated, and is an official product of the
Swift-XRT team.
GCN Circular 29482
Subject
GRB 210211A: Fermi GBM observation
Date
2021-02-11T20:30:18Z (4 years ago)
From
Joshua Wood at MSFC/Fermi-GBM <joshua.r.wood@nasa.gov>
J. Wood (NASA/MSFC), A. von Kienlin (MPE), and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 08:43:18.66 UT on 11 February 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 210211A (trigger 634725803 / 210211363)
which was also detected by the Swift/BAT and Swift/XRT (E. Troja et al. 2021, GCN 29472).
The Fermi GBM Final Real-time Localization (GCN 29470) is consistent with the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 50.5 degrees.
The GBM light curve shows multiple peaks
with a duration (T90) of about 29 s (50-300 keV).
The time-averaged spectrum from T0-4 s to T0+27 s is
best fit by a Band function with Epeak = 95 +/- 35 keV,
alpha = 2.8 +/- 3.1, and beta = -1.5 +/- 0.1.
The event fluence (10-1000 keV) in this time interval is
(3.1 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+3.8 s in the 10-1000 keV band
is 1.8 +/- 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 29483
Subject
GRB 210211A: Swift-BAT refined analysis
Date
2021-02-11T20:52:22Z (4 years ago)
From
Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov>
C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
Using the data set from T-240 to T+600 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 210211A (trigger #1032024)
(Troja, et al., GCN Circ. 29472). The BAT ground-calculated position is
RA, Dec = 269.408, -46.270 deg which is
RA(J2000) = 17h 57m 38.0s
Dec(J2000) = -46d 16' 11.0"
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.
The mask-weighted light curve shows a single broad peak starting at T-1 sec,
and decaying to background by T+8 sec. T90 (15-350 keV) is 6.1 +- 0.6 sec
(estimated error including systematics).
The time-averaged spectrum from T-0.70 to T+5.90 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.09 +- 0.16. The fluence in the 15-150 keV band is 4.2 +- 0.4 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+4.28 sec in the 15-150 keV band
is 1.0 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1032024/BA/
GCN Circular 29484
Subject
GRB 210211A: Swift-XRT refined Analysis
Date
2021-02-11T22:28:35Z (4 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto),
B. Sbarufatti (PSU), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAB), T.
Sbarrato (INAF-OAB) and E. Troja report on behalf of the Swift-XRT
team:
We have analysed 9.6 ks of XRT data for GRB 210211A (Troja et al. GCN
Circ. 29472), from 81 s to 40.6 ks after the BAT trigger. The data are
entirely in Photon Counting (PC) mode. The enhanced XRT position for
this burst was given by Osborne et al. (GCN Circ. 29478).
The light curve can be modelled with a power-law decay with a decay
index of alpha=1.15 (+0.09, -0.08).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.5 (+0.7, -0.6). The
best-fitting absorption column is 6.7 (+6.5, -3.6) x 10^21 cm^-2, in
excess of the Galactic value of 1.2 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 3.4 x 10^-11 (8.5 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 6.7 (+6.5, -3.6) x 10^21 cm^-2
Galactic foreground: 1.2 x 10^21 cm^-2
Excess significance: 2.5 sigma
Photon index: 2.5 (+0.7, -0.6)
If the light curve continues to decay with a power-law decay index of
1.15, the count rate at T+24 hours will be 7.2 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.4 x
10^-14 (6.1 x 10^-14) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01032024.
This circular is an official product of the Swift-XRT team.
GCN Circular 29485
Subject
GRB 210211A: Swift/UVOT Detection
Date
2021-02-11T22:59:12Z (4 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 210211A
78 s after the BAT trigger (Troja et al., GCN Circ. 29472). A source
consistent with the XRT position (Osborne et al. GCN Circ. 29478) and
the REM detection (d'Avanzo et al., GCN Circ. 29474)is detected in
the initial UVOT exposures.
The preliminary UVOT position is:
RA (J2000) = 17:57:45.68 = 269.44035 (deg.)
Dec (J2000) = -46:16:01.6 = -46.26711 (deg.)
with an estimated uncertainty of 0.47 arc sec. (radius, 90% confidence).
Preliminary detections and 3-sigma upper limits using the UVOT photometric
system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early
exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white 78 227 147 17.89 +/- 0.06
white 596 611 15 >18.6
white 5391 5587 197 >20.3
v 4239 4438 197 >19.8
b 545 565 19 >18.4
u 290 489 196 >18.6
m2 4444 4491 47 >18.3
w2 4034 4234 197 >19.4
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.127 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 29515
Subject
GRB 210211A: ePESSTO+ NTT optical observations
Date
2021-02-16T18:08:56Z (4 years ago)
From
Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>
L. Harvey, M. Magee (TCD), P. D'Avanzo (INAF-OAB), D. B. Malesani (DTU Space), S. Prentice, M. Deckers (TCD), S. Schulze (OKC), J. Teffs (LJMU),
S. Gonzalez-Gaitan (CENTRA), J. Anderson (ESO), T. Muller Bravo (Southampton), T.-W. Chen (Stockholm), M. Gromadzki (Warsaw), C. Inserra (Cardiff),
E. Kankare (Turku), M. Nicholl (Birmingham), O. Yaron (Weizmann), D. Young (QUB), I. Manulis (Weizmann), report:
We observed the field of GRB 210211A (Fermi GBM Team, GCN Circ. 29470; Troja et al., GCN Circ. 29472) under the advanced extended Public ESO
Spectroscopic Survey for Transient Objects (ePESSTO+; see Smartt et al. 2015, A&A, 579, 40 http://www.pessto.org <http://www.pessto.org/> ). The observations were performed
on the ESO New Technology Telescope at La Silla with the EFOSC2 instrument in imaging mode on 2021-02-16 between 08:01:05 UT and 08:42:23 UT
(i.e. about 4.99 days from the burst). The observations were carried out with the R filter under a seeing of about 1.9".
The optical afterglow (D'Avanzo et al., GCN Circ. 29474; Lipunov et al. GCN Circ. 29477; Kuin et al., GCN Circ. 29485) is not detected down to a 3sigma
limiting magnitude of R ~ 24.3 (Vega; based on preliminary photometry calibrated against the USNO B1 catalogue).