GRB 241212A
GCN Circular 38677
Subject
GRB 241212A: VZLUSAT-2 detection
Date
2024-12-27T06:45:12Z (10 months ago)
From
Jakub Ripa <ripa.jakub@gmail.com>
Via
Web form
J. Ripa, M. Dafcikova (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU) -- the VZLUSAT-2/GRB payload collaboration.
The long-duration GRB 241212A (Fermi/GBM detection: GCN 38540; AstroSat/CZTI detection: GCN 38544; SVOM detection: GCN 38541; INTEGRAL/SPI-ACS peak detection at 2024-12-12 09:21:47 UT) was detected by the GRB detector on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).
The data acquisition was performed by GRB detector unit no. 1. The detection was confirmed at the peak time 2024-12-12 09:21:48 UTC. The T90 duration measured by VZLUSAT-2 is 25 s and the significance during T90 reaches 7.1 sigma.
The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB241212A_GCN_VZLUSAT2.pdf
All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/
The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral.
GCN Circular 38579
Subject
GRB 241212A: Swift-XRT observations
Date
2024-12-16T06:42:41Z (10 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti
(INAF-OAB), D.N. Burrows (PSU), M. A. Williams (PSU), S. Dichiara
(PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester) and P.A.
Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the
SVOM/ECLAIRs-detected burst GRB 241212A, collecting 2.3 ks of Photon
Counting (PC) mode data between T0+257.0 ks and T0+297.7 ks.
No X-ray sources have been detected within the estimated 3-sigma
SVOM/ECLAIRs error region (118 arcsec). The 3-sigma upper limit in the
field is 0.004 ct s^-1, corresponding to a 0.3-10 keV observed flux of
1.4e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum).
An uncatalogued was detected, however this was too far from the GRB
position to be the afterglow.
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00021740.
This circular is an official product of the Swift-XRT team.
GCN Circular 38561
Subject
GRB 241212A: Fermi GBM detection
Date
2024-12-13T15:43:11Z (10 months ago)
From
Joe Mangan at IJCLab <joseph.mangan@ijclab.in2p3.fr>
Via
Web form
J. Mangan (CNRS/IJCLab) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 09:21:48.66 UT on 12 December 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241212A (trigger 755688113 / 241212390), which was also detected by, SVOM-GRM (Zhang Li et al. 2024, GCN 38541), and for which there is a possible optical counterpart (P.A. Evans et al. 2024, GCN 38559).
The Fermi GBM Final Real-time Localization is reported in GCN 38540. The angle from the Fermi LAT boresight at the GBM trigger time is 40 degrees.
The GBM light curve consists of a single emission with a duration (T90) of about 39 s (50-300 keV). The time-averaged spectrum from T0-0 s to T0+34 s is best fit by
a power law function with an exponential high-energy cutoff. The power law index is -1.1 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 304.8 +/- 59.1 keV. The event fluence (10-1000 keV) in this time interval is (5.8 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+4.4 s in the 10-1000 keV band is 2.8 +/- 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 38559
Subject
GRB 241212A: Swift ToO observations
Date
2024-12-13T15:26:28Z (10 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a ToO observation of the SVOM/ECLAIRs GRB 241212A.
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021740
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 SVOM/ECLAIRs 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 38551
Subject
GRB241212A: OHP/T193 optical observations
Date
2024-12-13T10:32:53Z (10 months ago)
Edited On
2024-12-13T13:30:49Z (10 months ago)
From
Christophe Adami at LAM <christophe.adami@lam.fr>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Christophe Adami at LAM <christophe.adami@lam.fr>
Via
Web form
C. Adami (LAM/Pytheas/AMU), J. Schmitt (OHP/Pytheas/AMU), S. Basa (LAM/OHP/Pytheas/AMU) report
on behalf of a larger collaboration:
We observed the field of GRB241212A (Fermi GBM team, GCN 38540; Zhang Li et al., GCN 38541; Joshi
et al., GCN 38544; Qiu et al., GCN 38545; Zhe Kang et al., GCN 38546) using the T193cm telescope
at Observatoire de Haute-Provence (France) equipped with the MISTRAL spectro-imager. Six exposures
were obtained in the Y-band (6x300s) with the MISTRAL red mode during technical time from 2024 12
December 18:43 UT to 2024 12 December 19:15 UT (~+9.5h after detection). The moon was at an
illumination of ~92% and at a distance of 13deg from target.
We do not detect the SVOM VT GRB counterpart provided by Qiu et al. (GCN 38545). The combined
frame has a detection upper limit of Y~19.25+/-0.6 (5sigma limit). The photometric calibration
was performed using objects from the PanSTARRS catalog. The magnitude is not corrected for
Galactic extinction.
We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Jean Pierre
Troncin, Francois Huppert, and Jean-Claude Brunel and the SOPHIE observers Guillaume Hebrard and Florian Destriez.
GCN Circular 38546
Subject
GRB 241212A : SVOM/C-GFT optical upper limit at early phase
Date
2024-12-13T00:58:36Z (10 months ago)
From
Chao Wu at NAOC <cwu@nao.cas.cn>
Via
Web form
SVOM/C-GFT team: Zhe Kang (CHO), Chao WU (NAOC), Liping Xin(NAOC), Xuhui Han(NAOC), Pinpin Zhang (NAOC), Xiaomeng Lu (NAOC), Zhenwei Li (CHO), You Lv (CHO), Ruosong Zhang (NAOC), Yujie Xiao(NAOC)
SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC),Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV)
We observed the field of GRB 241212A (Zhang et. al, GCN 38541; Fermi team GCN 38540;Joshi et al. GCN 38544) starting at 2024-12-12T09:22:45 UT, ~53 sec after the burst trigger with C-GFT. A series of g, r and i band images were obtained with exposure time of 10s. Due to bad observation condition(not good weather, low altitude and ~13.8 deg to the moon), the optical counterpart reported by Qiu et al. (GCN 38545) was not detected in the images. The upper limit at early phase are,
(T-T0)_mid(sec) limiting_mag(3sigma)
-------------------------------------
58 15.80
91 16.80
The photometry was calibrated with nearby stars in ucac4.
We thank the observation assistant Bowen Li and Chunlei Guo at Jilin observatory for their excellent support.
Chinese Ground Follow-up Telescope of SVOM mission is located at Jilin, Changchun Observatory, National Astronomical Observatories, CAS. It has FOV of 1.28 deg x 1.28 deg with a 4k*4k CMOS detector mounted on the primary focus of 1.2-meter-aperure telescope.
GCN Circular 38545
Subject
GRB 241212A : SVOM/VT bright optical afterglow
Date
2024-12-12T20:40:17Z (10 months ago)
From
Liping Xin at NAOC, SVOM <xlp@nao.cas.cn>
Via
Web form
SVOM/VT commissioning team: Y. L. Qiu, H. L. Li, L. P. Xin, C. Wu, X. H. Han, J. Wang, W. J. Xie, H. B. Cai, Y. Xu, Y. J. Xiao, P. P. Zhang, J. S. Deng, L. Lan, X. M. Lu, R. S. Zhang, J. Zhang, L. J. Dan, G. Y. Zou, C. J. Wang, Y. F. Du, C. Huang (XIOPM), H. Zhou (PMO), Li Zhang (IHEP)
SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV)
report on behalf of the SVOM team:
The GRB 241212A (Zhang et al., GCN 38541; Fermi GBM team et al., GCN 38540) was observed by on-board SVOM/VT after the automatic slew of the platform. The VT conducted observations in VT_B (400nm-650nm) and VT_R (650nm-1000nm) channel simultaneously.
With the X band downlinked data, an uncatalogued optical source was detected in VT_B and VT_R band images within the errorbox in both Eclairs and MXT (Zhang et al., GCN 38541) compared to the Desi D10 catalog. The source is located at RA, Dec = 45.08033, 6.71682, which is equivalent to:
RA (J2000) : 03:00:19.28
Dec (J2000): +06:43:00.56
with an uncertainty of 0.2 arcsec.
Its brightness was fading for 1.1 magnitude in both of VT_B and VT_R images from 0.7 hours to 4.8 hours after the burst. The magnitude was VT_B = 20.60 mag and VT_R = 19.88 mag in AB magnitude,about 1.15 hr post the trigger.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. VT was jointly developed by Xi'an Institute of Optics and Precision Mechanics (XIOPM), CAS and National astronomical observatories (NAOC),CAS.
GCN Circular 38544
Subject
GRB 241212A: AstroSat CZTI detection
Date
2024-12-12T15:45:53Z (10 months ago)
From
Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>
Via
Web form
J. Joshi (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long-duration GRB 241212A which was also detected by Fermi/GBM (Fermi-GBM Team, GCN Circ. 38540), and SVOM/ECLAIRs (Li et al., GCN Circ. 38541).
The source was clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2024-12-12 09:21:49.4 UTC. The measured peak count rate associated with the burst is 238 (+71, -38) counts/s above the background in the combined data of all quadrants, with a total of 1473 (+319, -369) counts. The local mean background count rate was 1331 (+6, -7) counts/s. We measure a T90 of 14 (+1, -6) s from the cumulative Veto light curve.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grbs
GCN Circular 38541
Subject
GRB 241212A: SVOM detection of a bright long burst
Date
2024-12-12T10:40:13Z (10 months ago)
Edited On
2024-12-12T15:19:18Z (10 months ago)
From
SVOM_group <svomgroup@bao.ac.cn>
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of SVOM_group <svomgroup@bao.ac.cn>
Via
Web form
Zhang Li (IHEP), Wenjin Xie (NAOC), Nicolas Dagoneau, Stéphane Schanne (CEA), Maria-Grazia Bernardini (INAF, LUPM), Clara Plasse (CEA), Shaolin Xiong (IHEP) report:
At 2024-12-12T09:21:49 (Tb) SVOM/ECLAIRs triggered on GRB 241212A (SVOM burst-id sb24121201), also detected by Fermi GBM (GCN Circular 38540).
The following trigger information was received on the ground with low-latency by the SVOM VHF Alert Network. A total of 12 Alerts were received from Count-Rate Trigger (CRT) and Image Trigger (IMT). The best Alert was produced by CRT with a signal-to-noise ratio of 35.5 in the 8-120 keV energy band over a time window of 20.48 s starting at Tb. The light curve shows a single broad peak of duration of about 40 s.
The localization of the best Alert is RA, Dec = 45.119, 6.701 (J2000) with a 90% C.L. radius of 2.9 arcmin (including a systematic error of 2 arcmin added in quadrature).
GRM light curve showed a broad peak structure with a T90 duration of about 40 s. The SVOM/GRM light curve can be found here:
https://www.bursthub.cn//admin/static/svgrb241212A.png
SVOM slewed automatically to the burst.
MXT began observing the field at 2024-12-12T09:24:05, 133 seconds after Tb, during an exposure of 6 seconds, before SAA entry.
Using onboard processed data we found one uncatalogued X-ray source located at RA, Dec 45.087, 6.719 degrees with a 90% C.L. radius of 70 arcseconds, corresponding to:
RA = 03h 00m 21s
Dec = 06° 43' 08"
This location is 2.2 arcminutes from the ECLAIRs onboard position.
VT began observing the field after the slew. The analysis of the recorded images will be published in a future circular on the follow-up of the SVOM optical instruments.
Burst Advocate for this burst is Zhangli (zhangli@ihep.ac.cn). Please contact the BA by email if you require additional information regarding the SVOM follow-up of this burst.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe.
GCN Circular 38540
Subject
GRB 241212A: Fermi GBM Final Real-time Localization
Date
2024-12-12T09:32:08Z (10 months ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 09:21:48 UT on 12 Dec 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 241212A (trigger 755688113.6612 / 241212390).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 44.3, Dec = 6.5 (J2000 degrees, equivalent to J2000 02h 57m, 6d 30'), with a statistical uncertainty of 3.6 degrees.
The angle from the Fermi LAT boresight is 40.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241212390/quicklook/glg_skymap_all_bn241212390.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241212390/quicklook/glg_healpix_all_bn241212390.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2024/bn241212390/quicklook/glg_lc_medres34_bn241212390.gif