GRB 211211A
GCN Circular 31201
Subject
GRB 211211A: Fermi GBM Final Real-time Localization
Date
2021-12-11T13:20:10Z (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 13:09:59 UT on 11 Dec 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 211211A (trigger 660921004.65092 / 211211549).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 211.3, Dec = 27.1 (J2000 degrees, equivalent to J2000 14h 05m, 27d 06'), with a statistical uncertainty of 1.0 degrees.
The angle from the Fermi LAT boresight is 111.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211211549/quicklook/glg_skymap_all_bn211211549.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/bn211211549/quicklook/glg_healpix_all_bn211211549.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211211549/quicklook/glg_lc_medres34_bn211211549.gif
GCN Circular 31202
Subject
GRB 211211A: Swift detection of a bright burst
Date
2021-12-11T13:32:57Z (4 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
A. D'Ai (INAF-IASFPA), E. Ambrosi (INAF-IASFPA),
V. D'Elia (SSDC & INAF-OAR), J.D. Gropp (PSU), J. A. Kennea (PSU),
N. P. M. Kuin (UCL-MSSL), A. Y. Lien (U Tampa),
F. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),
D. M. Palmer (LANL), T. M. Parsotan (GSFC/UMBC/CRESSTII) and
B. Sbarufatti (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 13:09:59 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 211211A (trigger=1088940). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 212.272, +27.884d which is
RA(J2000) = 14h 09m 05s
Dec(J2000) = +27d 53' 01"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). Due to a telemetry dropout, the immediately
available BAT lightcurve starts at T+8s, and shows a bright complex
burst that extends at least to T+100s. At T+8s the count rate is
300k counts/sec (15-350 keV), but the earlier peak may be significantly
higher.
The XRT began observing the field at 13:11:18.7 UT, 79.2 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 212.2912, 27.8899 which is equivalent to:
RA(J2000) = 14h 09m 9.89s
Dec(J2000) = +27d 53' 23.6"
with an uncertainty of 5.0 arcseconds (radius, 90% containment). This
location is 64 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.
UVOT took a finding chart exposure of nominal 150.000 seconds with the White
filter starting 87 seconds after the BAT trigger. No credible afterglow
candidate has been found in the initial data products. Data from the 2.7'x2.7'
sub-image are not available at this time. The 8'x8' region for the list of
sources generated on-board covers 100% of the XRT error circle. The list of
sources is typically complete to about 18 mag. No correction has been made for
the expected extinction corresponding to E(B-V) of 0.018.
Burst Advocate for this burst is A. D'Ai (antonino.dai AT inaf.it).
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 31203
Subject
GRB 211211A: KAIT Optical Afterglow Candidate
Date
2021-12-11T14:37:08Z (4 years ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on
behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift GRB 211211A (Trigger 1088940)
starting at Dec. 11, 13:46:25 UT. We detected an uncataloged
optical afterglow candidate at position (error ~0.5"):
RA: 14:09:10.09 (J2000)
Dec: +27:53:18.23 (J2000)
We estimate the clear band magnitude ~20.3 in out clear band image
at ~0.63 hours after burst. We can not estimate the variability
at this time, further observations are encouraged.
We also notice the afterglow candidate location is very close to a
SDSS galaxy (SDSS ID: 1237665429707096375, with r = 19.53 mag),
it is unclear if the galaxy is related to the GRB.
GCN Circular 31205
Subject
GRB 211211A: Enhanced Swift-XRT position
Date
2021-12-11T19:41:53Z (4 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1514 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 211211A, 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 = 212.29202, +27.88857 which is equivalent
to:
RA (J2000): 14h 09m 10.09s
Dec (J2000): +27d 53' 18.8"
with an uncertainty of 2.1 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 31206
Subject
Fermi GRB 211211A: Global MASTER-Net observations report
Date
2021-12-11T21:45:07Z (4 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov,
D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina,
A.Chasovnikov, V.Topolev, V.Grinshpun, 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
(Irkutsk State University, API),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov
(Blagoveschensk Educational State University)
MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 211211A ( Fermi GBM team, GCN 31201) errorbox 29692 sec after notice time and 29701 sec after trigger time at 2021-12-11 21:25:00 UT, with upper limit up to 13.5 mag. The observations began at zenith distance = 39 deg. The sun altitude is -17.3 deg.
The galactic latitude b = 73 deg., longitude l = 37 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1810719
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
29791 | 2021-12-11 21:25:00 | MASTER-Amur | (14h 05m 02.43s , +27d 44m 17.7s) | C | 180 | 13.5 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 31209
Subject
GRB 211211A: Swift-BAT refined analysis
Date
2021-12-12T03:14:09Z (4 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
M. Stamatikos (OSU), S. D. Barthelmy (GSFC),
A. D'Ai (INAF-IASFPA), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU)
(i.e. the Swift-BAT team):
Using the data set from T-240 to T+360 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 211211A (trigger #1088940)
(D'Ai et al., GCN Circ. 31202). The BAT ground-calculated position is
RA, Dec = 212.272, 27.884 deg which is
RA(J2000) = 14h 09m 05.2s
Dec(J2000) = +27d 53' 03.8"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 21%.
The mask-weighted light curve shows a multi-peaked structure that
starts at ~T0 and ends at ~T+140 s. The main peak occurs at ~T+7 s.
T90 (15-350 keV) is 51.37 +- 0.80 sec (estimated error including
systematics).
The time-averaged spectrum from T0 to T+142.2 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.56 +- 0.02. The fluence in the 15-150 keV band is 1.5 +- 0.02 x 10^-04
erg/cm2.
The 1-sec peak photon flux measured from T+6.86 sec in the 15-150 keV band
is 155.0 +- 3.1 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/1088940/BA/
GCN Circular 31210
Subject
GRB 211211A: Fermi GBM observation
Date
2021-12-12T07:31:36Z (4 years ago)
From
Joe Mangan at UCD <joseph.mangan@ucdconnect.ie>
J.Mangan (UCD), R.Dunwoody (UCD) and C.Meegan (UAH)
report on behalf of the Fermi GBM Team:
At 13:09:59.651 UT on 11 December 2021, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 211211A (trigger 660921004 / 211211549)
which was also detected by the Swift/BAT (D'Ai et al., GCN 31202). The
Fermi GBM Final Real-time Localization (GCN 31201) is consistent with
the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 106.5 degrees.
The GBM light curve consists of an exceptionally bright emission made
up of three separate pulses
with a duration (T90) of about 34.3s (50-300 keV).
The time-averaged spectrum from T0-1.264 s to T0+54.033 s is
best fit by a Band function with Epeak = 646.8 +/- 7.8 keV,
alpha = -1.3 +/- 0.00, and beta = -2.4 +/- 0.02
The event fluence (10-1000 keV) in this time interval is
(5.4 +/- 0.01)E-04 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+6.8 s in the 10-1000 keV band
is 324.9 +/- 1.5 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 31212
Subject
GRB 211211A: Swift-XRT refined Analysis
Date
2021-12-12T11:39:52Z (4 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), E. Ambrosi
(INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR),
D.N. Burrows (PSU), J. D. Gropp (PSU), J.A. Kennea (PSU), A.P.
Beardmore (U. Leicester) and A. D'Ai report on behalf of the Swift-XRT
team:
We have analysed 8.1 ks of XRT data for GRB 211211A (D'Ai et al. GCN
Circ. 31202), from 69 s to 74.2 ks after the BAT trigger. The data
comprise 214 s in Windowed Timing (WT) mode (the first 9 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 31205).
The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=1.99 (+0.13, -0.10). At T+171 s the decay
steepens to an alpha of 4.19 (+0.31, -0.21). The light curve breaks
again at T+704 s to a decay with alpha=-0.4 (+0.7, -0.6), before a
final break at T+5861 s s after which the decay index is 1.63 (+0.15,
-0.13).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.80 (+/-0.03). The
best-fitting absorption column is 4.5 (+/-0.8) x 10^20 cm^-2, in
excess of the Galactic value of 1.8 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.50 (+0.12, -0.06)
and a best-fitting absorption column consistent with the Galactic
value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum is 4.2 x 10^-11 (4.3 x 10^-11) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.8 (+2.5, -0.0) x 10^20 cm^-2
Galactic foreground: 1.8 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index: 1.50 (+0.12, -0.06)
If the light curve continues to decay with a power-law decay index of
1.63, the count rate at T+24 hours will be 0.020 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 8.7 x
10^-13 (8.9 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01088940.
This circular is an official product of the Swift-XRT team.
GCN Circular 31213
Subject
GRB 211211A: Nanshan/NEXT optical observations
Date
2021-12-12T11:42:12Z (4 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
S.Q. Jiang (NAOC), Z.P. Zhu (NAOC, HUST), S.Y. Fu, X. Liu, D. Xu (NAOC),
X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 211211A detected by Fermi (Fermi GBM team,
GCN 31201) and Swift (D'Ai et al., GCN 31202) using the NEXT-0.6m
optical telescope located at Nanshan, Xinjiang, China. Observations
started at 23:01:09 UT on 2021-12-11, i.e., 9.85 hr after the BAT
trigger, and 10x200 s frames in the Sloan r-filter as well as 12x200 s
frames in the Sloan z-filter were obtained.
The optical afterglow candidate of the GRB reported by KAIT (Zheng &
Filippenko, GCN 31203), consistent with the enhanced Swift-XRT position
(Beardmore et al., GCN 31205), is detected in our stacked r- and z-band
images. Preliminary photometry is as follows:
T_mid-T0 (hr) Mag MagErr Filter
10.34 20.29 0.07 r
10.68 19.9 0.3 z
both calibrated with nearby PS1 stars.
We note that the NEXT's r-band magnitude is comparable to that of KAIT
in the clear band, although the time interval of the two observations is
~10 hr.
GCN Circular 31214
Subject
GRB 211211A: LCO Optical Observations
Date
2021-12-12T12:50:00Z (4 years ago)
From
Robert Strausbaugh at U. of the Virgin Islands <robert.strausbaugh@uvi.edu>
R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (College of Marin) report on behalf of a larger collaboration:
We observed Swift GRB 211211A (D'Ai et al., GCN 31202) with the LCO 1-m Sinistro instrument at the Teide Observatory, Tenerife site, on December 12, from 05:57 to 06:33 UT (corresponding to 16.8 to 17.4 hours from the GRB trigger time) with the Bessel R and I filters.
We performed a series of 3x400s exposures in R and I bands. We detect a source in both R-band and I-band that is consistent with the Swift Enhanced XRT coordinates (Osborne, et al., GCN 31212) and the optical observations by KAIT (Zheng et al., GCN 31203) and Nanshan/NEXT (Jiang et al., GCN 31213); there appears to be fading in the R band compared to those earlier observations. The following magnitudes are calculated using the USNO-B.1 catalog as reference:
R=20.83+/-0.09
I=21.49+/-0.25
These magnitudes are not corrected for galactic extinction.
R.S. is funded by NSF AST grant #1831682
GCN Circular 31216
Subject
Swift GRB 211211A: Global MASTER-Net observations report
Date
2021-12-12T13:10:09Z (4 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov,
D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, T.Pogrosheva, E.Minkina,
A.Chasovnikov, V.Topolev, V.Grinshpun, 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
(Irkutsk State University, API),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov
(Blagoveschensk Educational State University)
MASTER-Amur robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Blagoveshchensk State Pedagogical University) was pointed to the Swift GRB 211211A ( A. D'Ai et al., GCN 31202) errorbox 29687 sec after notice time and 29621 sec after trigger time at 2021-12-11 21:25:00 UT, with upper limit up to 13.5 mag. The observations began at zenith distance = 39 deg. The sun altitude is -17.3 deg.
MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the Swift GRB 211211A errorbox 35200 sec after notice time and 35135 sec after trigger time at 2021-12-11 22:56:53 UT, with upper limit up to 19.1 mag. The observations began at zenith distance = 80 deg. The sun altitude is -59.4 deg.
MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 211211A errorbox 37423 sec after notice time and 37358 sec after trigger time at 2021-12-11 23:33:56 UT, with upper limit up to 17.2 mag. The observations began at zenith distance = 79 deg. The sun altitude is -58.1 deg.
MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) was pointed to the Swift GRB 211211A errorbox 52860 sec after notice time and 52795 sec after trigger time at 2021-12-12 03:51:13 UT, with upper limit up to 18.9 mag. The observations began at zenith distance = 76 deg. The sun altitude is -50.4 deg.
The galactic latitude b = 72 deg., longitude l = 39 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=1810696
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
29712 | MASTER-Amur | C | 180 | 13.5 |
35165 | MASTER-Kislovodsk | C | 60 | 17.4 |
35165 | MASTER-Kislovodsk | C | 60 | 17.5 |
35706 | MASTER-Kislovodsk | C | 180 | 18.0 |
35706 | MASTER-Kislovodsk | C | 180 | 18.2 |
36851 | MASTER-Kislovodsk | C | 60 | 17.4 |
36851 | MASTER-Kislovodsk | C | 60 | 17.7 |
37448 | MASTER-Tavrida | C | 180 | 17.1 |
37472 | MASTER-Kislovodsk | C | 180 | 18.3 |
37472 | MASTER-Kislovodsk | C | 180 | 18.6 |
38013 | MASTER-Kislovodsk | C | 60 | 17.5 |
38013 | MASTER-Kislovodsk | C | 60 | 18.0 |
38452 | MASTER-Tavrida | C | 60 | 17.0 |
39166 | MASTER-Tavrida | C | 60 | 17.2 |
39404 | MASTER-Tavrida | C | 60 | 17.1 |
40330 | MASTER-Tavrida | C | 60 | 15.6 |
40488 | MASTER-Tavrida | C | 60 | 15.1 |
40697 | MASTER-Kislovodsk | C | 180 | 18.3 |
40697 | MASTER-Kislovodsk | C | 180 | 18.4 |
41906 | MASTER-Tavrida | C | 60 | 12.8 |
41960 | MASTER-Kislovodsk | C | 60 | 18.0 |
42458 | MASTER-Tavrida | C | 60 | 12.2 |
42921 | MASTER-Kislovodsk | C | 60 | 18.3 |
43375 | MASTER-Tavrida | C | 180 | 13.2 |
43594 | MASTER-Tavrida | C | 60 | 12.0 |
43883 | MASTER-Kislovodsk | C | 60 | 18.3 |
48892 | MASTER-Kislovodsk | C | 180 | 18.9 |
48892 | MASTER-Kislovodsk | C | 180 | 19.1 |
49751 | MASTER-Tavrida | C | 180 | 14.4 |
49972 | MASTER-Tavrida | C | 60 | 13.9 |
50256 | MASTER-Kislovodsk | C | 180 | 18.5 |
50256 | MASTER-Kislovodsk | C | 180 | 18.5 |
50288 | MASTER-Tavrida | C | 60 | 13.2 |
51619 | MASTER-Kislovodsk | C | 180 | 16.8 |
51619 | MASTER-Kislovodsk | C | 180 | 14.5 |
52825 | MASTER-IAC | C | 60 | 16.3 |
52905 | MASTER-IAC | C | 60 | 14.0 |
52985 | MASTER-IAC | C | 60 | 17.3 |
54066 | MASTER-Tavrida | C | 60 | 15.2 |
54626 | MASTER-IAC | C | 60 | 17.4 |
54706 | MASTER-IAC | C | 60 | 17.4 |
54786 | MASTER-IAC | C | 60 | 17.6 |
55666 | MASTER-IAC | C | 60 | 17.5 |
55746 | MASTER-IAC | C | 60 | 17.9 |
56120 | MASTER-IAC | C | 60 | 17.9 |
59363 | MASTER-IAC | C | 180 | 18.7 |
59363 | MASTER-IAC | C | 180 | 18.7 |
60352 | MASTER-IAC | C | 180 | 18.9 |
60352 | MASTER-IAC | C | 180 | 18.7 |
61693 | MASTER-IAC | C | 180 | 18.9 |
61693 | MASTER-IAC | C | 180 | 18.7 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 31217
Subject
GRB 211211A: MITSuME Akeno optical observation
Date
2021-12-12T13:18:20Z (4 years ago)
From
Naohiro Ito at Tokyo Tech <n.ito@hp.phys.titech.ac.jp>
N. Ito, R. Hosokawa, K. L. Murata, Y. Imai, Y. Takamatsu, M. Takaku, M.
Niwano, R. Noto, S. Sato, R. Yamaguchi, Y. Yatsu, and N. Kawai (TokyoTech)
report on behalf of the MITSuME collaboration:
We observed the field of GRB 211211A (The Fermi GBM team GCN Circular
#31201, A. D'Ai et al. GCN Circular #31202, WeiKang Zheng and Alexei V.
Filippenko GCN Circular #31203, A.P. Beardmore et al. GCN Circular #31205,
V. Lipunov et al. GCN Circular #31206, M. Stamatikos et al. GCN Circular
#31209, J.Mangan et al. GCN Circular #31210, J.P. Osborne et al. GCN
Circular #31212, S.Q. Jiang et al. GCN Circular #31213, R. Strausbaugh and
A. Cucchiara GCN Circular #32214) with the optical three color (g', Rc, and
Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno. The
observation with a series of 60 sec exposures was carried out from
2021-12-11 17:32:12 UT (~4.4 hours after the Fermi trigger) to 2021-12-11
21:20:21 UT. We stacked the images with good conditions.
We marginally detected the optical afterglow candidate reported by the KAIT
observation (WeiKang Zheng and Alexei V. Filippenko GCN Circular #31203),
Nanshan/NEXT observation (S.Q. Jiang et al. GCN Circular #31213) and LCO
observation (R. Strausbaugh and A. Cucchiara GCN Circular #32214) in our
g'-, Rc- and Ic- band images. The candidate in our images is blended with
the nearby SDSS galaxy (SDSS ID: 1237665429707096375, reported by GCN
Circular #31203). We performed forced photometry at the position of the
candidate against the nearby galaxy. The magnitudes and the 5-sigma limits
of the stacked images are as follows.
T0+[hour] | MID-UT | T-EXP[sec] | candidate magnitude | 5-sigma limits
------------------------------------------------------------------------------------------------
6.3 | 2021-12-11 19:25:34 | 6600 | g'=20.4 +/- 0.2, Rc=20.3 +/- 0.1,
Ic=20.4 +/- 0.3 | g'>20.2, Rc>20.7, Ic>19.7
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used id 141492123232234127 of PS1 catalog for flux calibration. The
conversion from PS1 r and i band to our Rc and Ic band is by the equation
of Tonry et al. (2012), Table. 6. The magnitudes are expressed in the AB
system. The images were processed in real-time through the MITSuME GPU
reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24;
https://github.com/MNiwano/Eclaire).
GCN Circular 31218
Subject
GRB 211211A: Afterglow detection from CAFOS/2.2m CAHA
Date
2021-12-12T13:53:45Z (4 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (Obs. Cote d���Azur), D.A. Kann, C. Thoene,
J.F. Agui Fernandez, M. Blazek (HETH/IAA-CSIC) and
A. Guijarro (CAHA) report:
We observed the optical afterglow of GRB 211211A (Fermi team
GCN31201; D���Ai et al. GCN31202; Zheng and Filipenko GCN
31203) with CAFOS, mounted on the 2.2m telescope, at the Calar
Alto Observatory (Almer��a, Spain). The observation started at
04:54 UT (15.73 hr after the GRB) and consisted of 30x90s in i-band.
The optical afterglow is well detected at a magnitude (AB) of
i = 20.83+/-0.05, as compared to field stars from the SDSS catalogue.
This magnitude confirms the plateau or very shallow decay phase
undergone by the afterglow light curve since the early detection
(Zheng and Filipenko GCN 31203) already noted by Jiang et al.
(GCN 31213) and consistent with the observations of Strausbaugh
& Cucchiara (GCN 31214) and Ito et al. (GCN 31217).
GCN Circular 31221
Subject
GRB 211211A: NOT optical spectroscopy
Date
2021-12-12T16:24:56Z (4 years ago)
From
Daniele B Malesani at Radboud U <d.malesani@astro.ru.nl>
D. B. Malesani (Univ. Radboud and DAWN/NBI), J. P. U. Fynbo (DAWN/NBI),
A. de Ugarte Postigo (Obs. Cote d'Azur), L. Izzo (DARK/NBI), S. Fu, D.
Xu, Z. Zhu (NAOC/CAS), N. R. Tanvir (Univ. Leicester), A. A. Djupvik
(NOT), report on behalf of a larger collaboration:
We observed the optical afterglow of GRB 211211A (D'Ai et al., GCN
31202; Zheng & Filippenko, GCN 31203) using the Nordic Optical Telescope
(NOT) equipped with the ALFOSC instrument. Images were secured in the
SDSS r, g and i filters.
At the mean time of Dec 12.24 UT (16.6 hr after the GRB), we measure a
magnitude r = 20.89 +- 0.05 AB, calibrated against nearby stars from the
Pan-STARRS survey. Our measurement is in agreement with those by
Strausbaugh & Cucchiara (GCN 31214) and de Ugarte Postigo et al. (GCN
31218), taken at a comparable epoch. Compared to the magnitudes reported
by Zheng & Filippenko (GCN 31203), Ito et al. (GCN 31217) and Jang (GCN
31213), our data confirm the unusually slow decay,
We report for the afterglow the following coordinates (0.3" uncertainty):
RA = 14:09:10.12
Dec = +27:53:18.1
A bright, extended object (r ~ 19.5) is visible about 5.5" to the N-E of
the afterglow (as already pointed out by Zheng & Filippenko, GCN 31203),
which is also visible in the SDSS, Pan-STARRS, and Legacy surveys.
A spectrum was secured covering both the afterglow and the nearby galaxy
(wavelength range 3700-9400 AA). A weak emission line is detected on top
of the host galaxy trace at 7063 AA, which could be due to Halpha at z =
0.076. This is marginally consistent with the SDSS photometric redshift
0.140 +- 0.0375, unlike other interpretations of the same line.
No clear absorption or emission features are detected in the afterglow
trace. This may be due to the modest S/N, and is also consistent with a
low redshift, as is the detection of the afterglow in all the UVOT UV
filters (Swift observation ID 1088940000).
It is not clear at the present stage whether the afterglow is physically
associated with the galaxy at z = 0.076. While the sky proximity and the
low redshift are indeed suggestive, the physical offset at z = 0.076
would be about 8 kpc (in projection), an unusually large value for long
GRBs. There is also no visible emission in the archival images down to r
~ 24 (AB) at the location of the afterglow, which would be unusual for a
long GRB at z = 0.076.
Moreover, if placed at z = 0.076, GRB 211211A would be an outlier of the
the Amati relation (e.g. Nava et al. 2012, MNRAS, 421, 1256), with E_iso
= 1.4*10^54 erg and E_peak ~ 700 keV (using the Fermi/GBM prompt
properties from Mangan et al., GCN 31210).
Overall, a moderate-redshift GRB (with z > 0.076) is consistent with the
available information. The detection of an emerging supernova could
clarify the situation. We encourage further photometric and
spectroscopic follow-up of this potentially interesting event.
GCN Circular 31222
Subject
GRB 211211A: Swift/UVOT detection
Date
2021-12-12T18:19:57Z (4 years ago)
From
Alexander Belles at PSU/Swift <aub1461@psu.edu>
A. Belles (PSU) and A. D'Ai (INAF-IASFPA)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 211211A
92 s after the BAT trigger (D'Ai et al., GCN Circ. 31202).
A fading source consistent with the XRT position
(Beardmore et al. GCN Circ. 31205) and optical position
(Zheng & Filippenko, GCN Circ. 31203) is detected in the initial
UVOT exposures.
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
wh_FC 92 242 147 18.93+/-0.22
wh 3906 4106 196 18.33+/-0.09
wh 68215 68397 179 >19.74
b 3701 3901 196 18.97+/-0.28
b 16837 17437 587 19.27+/-0.28
b 67303 68210 885 19.70+/-0.24
v 4317 4517 196 >18.33
u 3496 5012 275 18.26+/-0.16
u 15924 16831 885 18.44+/-0.11
u 57177 74247 362 >18.89
w1 4727 4927 196 17.46+/-0.16
m2 4522 4721 196 17.58+/-0.19
m2 21678 22153 467 18.18+/-0.18
w2 4112 4312 196 17.30+/-0.15
w2 61756 62656 885 18.94+/-0.24
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.018 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 31223
Subject
GRB 211211A: incorrect E_iso value in GCN 31221
Date
2021-12-12T18:45:59Z (4 years ago)
From
Daniele B Malesani at Radboud U <d.malesani@astro.ru.nl>
D. B. Malesani (Radboud Univ. and DAWN/NBI) reports:
The GRB 211211A E_iso value reported by Malesani et al. (GCN 31221) is
incorrect. Using the Fermi GBM fluence 5.4*10^-4 erg cm^-2 (Mangan et
al., GCN 31210), the corresponding E_iso value is 6.9*10^51 erg,
assuming the GRB is at z = 0.076.
The conclusion that GRB 211211A would not be consistent with the Amati
relation if at z = 0.076 was based on the correct E_iso value, and still
holds. This may indicate that the GRB lies in fact at a higher redshift.
I sincerely apologize for any confusion caused by this mistake, and I am
grateful to those who pointed it out, including Peter Veres, D.
Alexander Kann, and Lorenzo Amati. No blame should be assigned to the
other co-authors of GCN 31221, who saw an earlier draft which did not
contain the mistake.
GCN Circular 31226
Subject
GRB 211211A: CALET Gamma-Ray Burst Monitor detection
Date
2021-12-13T08:58:30Z (4 years ago)
From
Valentin Pal'shin at AGU <val@phys.aoyama.ac.jp>
T. Tamura (Kanagawa U),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu (Kanagawa U), N. Cannady (GSFC/UMBC), M. L. Cherry (LSU),
S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:
The long bright GRB 211211A (Swift detection: Ambrosi et al.,
GCN Circ. 31202, Stamatikos et al., GCN Circ. 31209;
Fermi GBM observation: Mangan et al., GCN Circ. 31210;
https://gcn.gsfc.nasa.gov/other/211211A.gcn3)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 13:09:57.513 UTC
on 11 December 2021
(http://cgbm.calet.jp/cgbm_trigger/flight/1323263412/index.html).
The burst signal was seen by all CGBM detectors.
The burst light curve shows several partially overlapped multi-peaked
pulses which start at T+3.6 sec, peak at T+9.1 sec,and end at T+73.1 sec.
The T90 and T50 durations measured by the SGM data are 33.8 +- 0.9 sec and
12.1 +- 0.4 sec (40-1000 keV), respectively.
The ground processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1323263412/
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at the Waseda University.
GCN Circular 31227
Subject
GRB 211211A: HCT and GIT optical follow up observations
Date
2021-12-13T11:11:53Z (4 years ago)
From
Harsh Kumar at Indian Inst of Tech,Bombay <harshkosli13@gmail.com>
H. Kumar(IITB), V. Bhalerao(IITB), Rahul Gupta(ARIES), Rigzin Norbu (IAO),
G. C. Anupama(IIA), D. K. Sahu (IIA), S. Barway(IIA), A. Dutta (IIA), B.
Kumar (ARIES), Dimple (ARIES), S.B. Pandey (ARIES), Kuntal Mishra (ARIES)
report on behalf of the HCT and GIT team:
We observed GRB 211211A detected by Fermi GBM (GCN #31201) and Swift-BAT
(A. D'Ai et al., GCN #31202); optical counterpart first reported by W Zheng
and A V. Filippenko, (GCN #31203) with 2.0m Himalayan Chandra Telescope
(HCT) and 0.7m GROWTH-India Telescope (GIT). We obtained a 900-sec exposure
in the Bessell R filter using HCT and multiple 300-sec r' band exposures
with GIT. We obtained the following photometric results:-
---------------------------------------------------------------------
JD (mid) | T_mid-T0(hrs) | Exposure | Filter | Magnitude | Tel |
---------------------------------------------------------------------
2459560.50469 | 10.94 | 900 sec | Bessell R | 20.30 +/- 0.13 | HCT |
2459561.47439 | 34.21 | 1500 sec | r' | > 21.19 | GIT |
---------------------------------------------------------------------
Our results from HCT are similar to R band magnitudes reported in N. Ito
et. al, (GCN #31217) which suggests that there was no significant decay in
the early hours ( <~11 hrs). GIT r' band observations at ~34 hrs did not
detect the afterglow, with a limiting magnitude of 21.19 - confirming the
fading of the afterglow at late times reported by R. Strausbaugh et. al.,
(GCN #31214).
The magnitudes were calibrated by querying the SDSS catalog (Alam+, 2015).
We converted magnitudes to the R band using Lupton (2005) equations for HCT
calibration.
HCT observations were carried out under the ToO program HCT-2021-C3-P02. We
thank HCT and GIT observers, staff for undertaking the observations.
The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7-degree
field of view, set up by the Indian Institute of Astrophysics (IIA) and the
Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and
IUSSTF. It is located at the Indian Astronomical Observatory (Hanle),
operated by IIA. We acknowledge funding by the IITB alumni batch of 1994,
which partially supports operations of the telescope. Telescope technical
details are available at https://sites.google.com/view/growthindia/.
GCN Circular 31228
Subject
GRB 211211A: Further observations from CAFOS/2.2m CAHA
Date
2021-12-13T17:22:44Z (4 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (Obs. Cote d���Azur), D.A. Kann, C. Thoene,
J.F. Agui Fernandez, M. Blazek (HETH/IAA-CSIC), I. Vico and
A. Guijarro (CAHA) report:
We obtained a second imaging observation of the optical afterglow
of GRB 211211A (Fermi team GCN31201; D���Ai et al. GCN31202;
Zheng and Filipenko GCN 31203) with CAFOS, mounted on the
2.2m telescope, at the Calar Alto Observatory (Almer��a, Spain).
The observation started at 04:47 UT (39.6 hr after the GRB) and
consisted of 30x90s in i-band. The optical afterglow is still detected,
at a magnitude (AB) of i = 22.45+/-0.09, as compared to field stars
from the SDSS catalogue. With respect to our earlier CAFOS
photometry (de Ugarte Postigo et al. GCN 31218) this implies a
rapid decay rate of alpha = 1.65, where F_nu ~ t^-alpha, which
would indicate a post-jet break evolution.
GCN Circular 31229
Subject
GRB 211211A: Very fast decay observed from CAFOS/2.2mCAHA
Date
2021-12-14T16:25:45Z (4 years ago)
From
Antonio de Ugarte Postigo at IAA-CSIC <deugarte@iaa.es>
A. de Ugarte Postigo (Obs. Cote d���Azur), D.A. Kann, C. Thoene,
J.F. Agui Fernandez, M. Blazek (HETH/IAA-CSIC), I. Vico and
A. Guijarro (CAHA) report:
We obtained further i-band imaging of the afterglow of GRB 211211A
(Fermi team GCN31201; D���Ai et al. GCN31202; Zheng and Filipenko
GCN 31203) from CAFOS/2.2m CAHA 2.66 days after the burst onset.
The observation consisted of 20x120s exposures under good seeing
and yielded a faint detection. The light curve decay, compared to our
previous observation from Calar Alto (de Ugarte Postigo et al., GCN
31228) indicates an extreme decay index of alpha = 3.25+/-0.40.
This is similar to what is observed from the XRT light curve, which
currently decays with an index of 3.2 (-0.7,+0.8)
(https://www.swift.ac.uk/xrt_live_cat/01088940/ <https://www.swift.ac.uk/xrt_live_cat/01088940/>; Evans et al. 2007;
Evans et al. 2009). We note that this is amongst the fastest post-break
decays that are normally observed for GRB afterglows.
Further observations with larger telescopes are encouraged.
GCN Circular 31230
Subject
GRB 211211A: redshift estimation and SPI-ACS/INTEGRAL detection
Date
2021-12-14T17:35:39Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
P. Minaev (IKI), A. Pozanenko (IKI) report on behalf of GRB IKI FuN:
We analyzed GRB 211211A (D'Ai et al. GCN 31202; Mangan et al. GCN 31210;
Tamura et al. GCN 31226) using publicly available data of GBM/Fermi and
SPI-ACS/INTEGRAL. Using GBM/Fermi we estimate a duration in 7 - 850 keV
energy band T_90 = 50.6 +/- 0.1 s, while the emission is seen at least
up to 130 s after the trigger. We performed spectral analysis in time
interval of (-0.5, 60) s, covering the main part of GRB activity. The
best fit is obtained for (Band model + thermal component) with following
parameters: E_p = 758 +/- 13 keV, alpha = -1.21 +/- 0.01, beta = -2.54
+/- 0.03 and thermal spectral component with kT = 13.9 +/- 0.3 keV. The
fluence of F = (5.47 +/- 0.01)E-4 erg/cm**2 is obtained in 10 - 1000 keV
energy band. The parameter E_p = 758 +/- 13 keV is higher than
preliminary value presented by GBM team (Mangan et al., GCN 31210) due
to inclusion of the thermal component in the fit.
Assuming a redshift of z = 0.076 (Malesani et al., GCN 31221) we
estimated E_iso = (1.161 +/- 0.006)E52 erg in the 1 keV - 10 MeV energy
band. The burst is placed very close but outside the 2 sigma correlation
region at E_p,i - E_iso and T_90,i - EH diagrams [1,2], see the Figures in
http://grb.rssi.ru/GRB211211A/GRB211211A_Ep-Eiso-2.png
http://grb.rssi.ru/GRB211211A/GRB211211A_EHD.png
Using T_90,i - EH diagram we found minimal possible redshift value of z
= 0.080, very close to the redshift of z = 0.076 (Malesani et al., GCN
31221). Therefore, we consider GRB 211211A as not a significant outlier.
The burst was also detected by SPI-ACS/INTEGRAL. Its duration in the
SPI-ACS energy band (> 80 keV) is T_90 = 30.0 +/- 0.2 s, while the
emission is seen up to 70 s. Comparing fluences of long-duration GRBs
simultaneously recorded by SPI-ACS and Fermi/GBM (Chelovekov et al., in
preparation) we estimated the GRB 211211A fluence to be 5.5E-4 erg/cm**2
in the 10-1000 keV energy band (the 95% confidence region 1.6-4 ��� 1.9E-3
erg/cm**2, incl. systematics). GRB 211211A is one of the brightest GRBs
of SPI-ACS/INTEGRAL sample in terms of peak flux (about 40000 cnts/50
ms). The SPI-ACS light curve of GRB 211211A can be found in
http://grb.rssi.ru/GRB211211A/GRB211211A_SPI-ACS_lc-2.png
[1] - Minaev et al., MNRAS, 492, 1919, 2020
[2] - Minaev et al., Astronomy Letters, 46, 9, 573, 2020
GCN Circular 31232
Subject
GRB 211211A: GMG upper limit
Date
2021-12-15T02:00:51Z (4 years ago)
From
Jirong Mao at Yunnan Obs <jirongmao_obs@ynao.ac.cn>
J. Mao, Y.-X. Xin, and J.-M. Bai (YNAO) report:
We observed the field of GRB 211211A (D'Ai et al. GCN 31202) by the GMG telescope in Yunnan observatories.
The observation began from UT 22:41:02 Dec 12, 2021, about 33.5 hours from the trigger. We could not observe
the optical afterglow down to a magnitude limit of r~22.0.
GCN Circular 31233
Subject
GRB 211211A: AbAO optical observations
Date
2021-12-15T15:44:10Z (4 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
N. Pankov (HSE, IKI), A. Pozanenko (IKI), S. Belkin (IKI), R. Ya.
Inasaridze (AbAO), D. Datashvili (AbAO), V. R. Ayvazian (AbAO), G. V.
Kapanadze (AbAO) report on behalf of GRB IKI FuN:
We observed the field of GRB 211211A (Fermi team GCN 31201, D'Ai et al.
GCN 31202; Mangan et al. GCN 31210; Tamura et al. GCN 31226) with AS-32
telescope of Abastumani observatory (AbAO) in R-filter on 2021-12-13
(UT) 02:21:44 and 2021-12-14 (UT) 01:49:33.
In the first epoch we marginally detected an afterglow (Zheng and
Filippenko GCN 31203; Jiang et al. GCN 31213; Strausbaugh et al. GCN
31214; Ito et al. GCN 31217; de Ugarte Postigo et al. GCN
31218,31228,31229; Malesani et al. GCN 31221; Belles et al. GCN 31222;
Kumar et al. GCN 31227). In the second epoch we obtained only an upper
limit.
Preliminary photometry of the field is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2021-12-13 02:21:44 1.56233 R 36*60 21.6 S/N=3 21.6
2021-12-14 01:49:33 2.52748 R 43*60 n/d n/d 21.8
The photometry is based on the nearby SDSS stars:
SDSS-DR12
RA DEC R(Lupton transfoemations)
14:09:08.84448 +27:53:54.5604 15.833
14:09:04.53240 +27:54:10.4760 16.701
14:08:57.03480 +27:54:50.2632 17.677
14:08:57.87816 +27:55:06.0924 17.805
14:09:03.80928 +27:55:56.5464 17.104
14:09:07.89072 +27:55:43.9968 18.640
GCN Circular 31234
Subject
GRB 211211A: SAO RAS optical observations
Date
2021-12-15T17:28:29Z (4 years ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
A. Moskvitin (SAO), O. Spiridonova (SAO), S. Belkin (IKI),
A. Pozanenko (IKI), N. Pankov (HSE, IKI) report
on behalf of GRB IKI FuN:
We observed the field of GRB 211211A (Fermi team GCN 31201,
D'Ai et al. GCN 31202; Mangan et al. GCN 31210; Tamura et al.
GCN 31226) with Zeiss-1000 telescope of SAO RAS in Rc-filter
on 2021.12.14 (UT) 02:03:33.
We marginally detected an afterglow (Zheng and Filippenko GCN 31203;
Jiang et al. GCN 31213; Strausbaugh et al. GCN 31214; Ito et al.
GCN 31217; de Ugarte Postigo et al. GCN 31218,31228,31229; Malesani et
al. GCN 31221; Belles et al. GCN 31222; Kumar et al. GCN 31227; Pankov
et al. GCN 31233).
Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err. UL(3sigma)
(mid, days) (s)
2021-12-14 02:03:33 2.55803 Rc 6*600 23.2 S/N=2.5 23.1
The photometry is based on the nearby SDSS stars:
SDSS-DR12
RA DEC R(Lupton transformations)
14:09:08.84 +27:53:54.56 15.833
14:09:04.53 +27:54:10.48 16.701
14:08:57.03 +27:54:50.26 17.677
14:08:57.88 +27:55:06.09 17.805
14:09:03.81 +27:55:56.55 17.104
14:09:07.89 +27:55:44.00 18.640
The light curve based on published photometry can be found in
http://grb.rssi.ru/GRB211211A/GRB211211A_LC.png
Using R-photometry we found a single power law decay index of -1.5
between 0.4 and 2.6 days after the burst trigger. However the power
law index between 1.6 days (Pankov et al. GCN 31233) and 2.6 days
(this circ.) we may assume power law index of -3.25 which confirm
very fast decay in i-filter observed by CAFOS/2.2mCAHA
(de Ugarte Postigo et al. GCN 31229). Based on a typical power law
decay of afterglows we may suggest a bump in the LC at ~ 2.5 days
followed by a power law decay index of 1.5.
GCN Circular 31235
Subject
GRB 211211A - Gemini K-band detection
Date
2021-12-15T21:19:50Z (4 years ago)
From
Andrew Levan at U.of Leicester <a.levan@astro.ru.nl>
A.J. Levan (Radboud), J. Rastinejad (Northwestern), B. Gompertz (Birmingham), W. Fong (Northwestern), D. B. Malesani (Radboud), M. Nicholl (Birmingham) report for a larger collaboration:
���We obtained K-band observations of GRB 211211A (D���Ai et al., GCN 31202) with the Gemini-North Telescope and NIRI. Observations began at 14:40 UT on 15 Dec 2021 (~4 days after the GRB). A total of 900 s of exposure were obtained.
At the location of the afterglow identified by Zheng & Fillipenko (GCN 31203) we clearly detect a K-band source. Photometry is complicated by the narrow field of view, however, using the 2MASS source at RA, DEC(J2000)=14:09:08,86, 27:53:54.4 with a magnitude of K=12.8, we determine an afterglow magnitude of K = 20.5 +/- 0.1 (Vega) or 22.4 +/- 0.1 (AB). This magnitude is substantially brighter than expected for afterglow emission given the rapid decay observed in the i-band (de Ugarte Postigo et al., GCN 31229), and the relatively blue colours and spectra of the source at earlier times (Malesani et al., GCN 31221; Belles & D���Ai, GCN 31222).
The rapid fading and relative faintness in the optical apparently rules out a classical long-GRB at z = 0.076, since a supernova akin to those seen in long GRBs at this epoch would have i ~ 20, 4 magnitudes brighter than observed by de Ugarte Postigo et al. (GCN 31229). Alternatively, the prompt light curve appears to show some similarities with GRB 060614, another suggested short-GRB with extended emission (Gehrels et al. 2006 Nature 444 1044). If GRB 211211A is associated with a compact object merger, its large offset relative to the putative host at z = 0.076 may be expected. The absolute magnitude of the source seen in the K-band is -15.2 (AB), comparable to that of AT2017gfo at the same epoch. Hence, while it remains possible that GRB 211211A is a higher redshift event in chance projection with a low redshift galaxy, a compact binary merger at z=0.076 provides a good explanation of the galactic location, rapid optical fading and red colour of the source.
We thank the Gemini staff for the rapid execution of these observations."
GCN Circular 31236
Subject
GRB 211211A: Insight-HXMT/HE detection
Date
2021-12-16T06:44:10Z (4 years ago)
From
Y Q Zhang at IHEP <yqzhang@ihep.ac.cn>
Y. Q. Zhang, S. L. Xiong, X. B. Li, C. Cai, Q. Luo, S. Xiao,
J. C. Liu, W. C. Xue, Q. B. Yi, C. Zheng���Y. Huang, C. K. Li,
G. Li, J. Y. Liao, X. Y. Song, 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 2021-12-11T13:09:59.500 (T0), Insight-HXMT/HE detected
GRB 211211A (trigger ID: HEB211211548) in a routine search of the data,
which also triggered Fermi/GBM (Fermi GBM Team, GCN #31201),
Swift/BAT (D'Ai A. et al., GCN #31202),
CALET (Tamura T. et al., GCN #31226) and
INTEGRAL/SPI-ACS (Minaev P. et al., GCN #31230)
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB211211548_lc.jpg
It should be noted that there is a significant saturation effect (data loss)
during bright parts of this GRB in HXMT.
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 31242
Subject
GRB 211211A: TNG NIR observations
Date
2021-12-16T12:40:41Z (4 years ago)
From
Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>
P. D'Avanzo (INAF-OAB), A. Rossi (INAF-OAS), D. B. Malesani (Radboud), V. D'Elia (ASI-SSDC), A. Melandri (INAF-OAB),
M. De Pasquale (Univ. Messina), S. Piranomonte (INAF-OAR), G. Andreuzzi, A. Garcia de Gurtubai (INAF-TNG)
on behalf of the CIBO collaboration report:
We observed the field of GRB 211211A (D���Ai et al., GCN Circ. 31202) with the Italian 3.6m TNG telescope equipped with the
near-infrared camera NICS. A series of images were obtained with the H filter on 2021-12-16 from 05:51:36 UT to 07:00:51 UT
(i.e. at a mid time of about 4.7 days after the burst).
No source is detected at the optical and NIR counterpart position (Zheng & Filippenko, GCN Circ. 31203; Levan et al., GCN Circ.
31235) down to the following 3sigma upper limit:
H > 20.5 (Vega) or H > 21.9 (AB)
(calibrated against the 2MASS catalogue).
GCN Circular 31264
Subject
GRB 211211A: MMT/MMIRS Observations Indicate Fading of K-band Source
Date
2021-12-18T21:26:07Z (4 years ago)
From
Wen-fai Fong at Northwestern U <wfong@northwestern.edu>
J. Rastinejad, W. Fong (Northwestern), A. J. Levan, D. B. Malesani (Radboud), J. Jencson, D. Sand (U. Arizona), N. R. Tanvir (Leicester) report:
We observed the location of GRB 211211A (D���Ai et al., GCN 31202) with the MMT and Magellan Infrared Spectrograph (MMIRS) instrument mounted on the MMT 6.5-meter telescope on Mount Hopkins, Arizona. At a mid-time of 2021 December 18.52 UT (~6.9 days post-burst), we obtained 126 x 30 s of K-band imaging at a median airmass of 1.5 and seeing of 0.8 arcsec. A faint K-band source is still detected at the location of the optical afterglow (first reported by Zheng & Fillipenko; GCN 31203). Based on calibration to 2MASS, we estimate a preliminary magnitude for the source of K_AB ~ 24 mag, although we caution that the faintness of the source precludes a precise measure at this time. Visual inspection relative to our Gemini K-band imaging (Levan et al. GCN 31235) is in support of clear fading of the source.
Taken at face value, the K-band source has declined by ~1.5 mag between ~4 and 7 days post-burst, while AT2017gfo only faded by ~0.4 mag in the K band (Villar et al., 2017, ApJL, 851, L21) on these same timescales.
Further observations are planned. We thank Joannah Hinz and ShiAnne Kattner at MMT for the rapid planning and execution of these observations.
GCN Circular 31299
Subject
GRB 211211A: observations with the 3.6m Devasthal Optical Telescope
Date
2021-12-24T16:40:23Z (4 years ago)
From
Rahul Gupta at ARIES, India <rahulbhu.c157@gmail.com>
Rahul Gupta, S. B. Pandey, A. Ror, A. Kumar, A. Aryan, Dimple, A. Ghosh, B.
Kumar, and K. Misra (ARIES) as a part of larger international collaboration:
We performed late-time photometric observations of the optical afterglow (Zheng
and Filipenko GCN 31203) of Fermi (Fermi GBM team, GCN 31201) and Swift (D'Ai
et al., GCN 31202) detected GRB 211211A using the 4Kx4K CCD Imager (Pandey
et al. 2017, arXiv:1711.05422v1) mounted at the axial port of the 3.6m
Devasthal Optical Telescope of ARIES Nainital at multiple epochs in several
filters. We report the preliminary brightness of the afterglow to be R =
21.66 +/- 0.07 mag ~ 1.41 days after the GBM trigger. At successive epochs,
we obtained the limiting mag of 23.7 mag ~ 4.42 days post-burst. Our
observations are consistent with the rapid decay nature of the afterglow
reported by de Ugarte Postigo et al. GCN 31229 and A. Moskvitin et al. GCN
31234.
The magnitude value reported is calibrated against UNSO B1 nearby stars.
This circular may be cited. 3.6m Devasthal Optical Telescope (DOT) is
the 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). Authors of this GCN circular thankfully
acknowledge consistent support from the staff members to run and maintain
the 3.6m DOT.