TITLE: GCN CIRCULAR
NUMBER: 35231
SUBJECT: GRB 231129C: GECAM-B detection of a bright burst
DATE: 23/11/30 10:03:59 GMT
FROM: yqzhang_cl(a)163.com
GRB 231129C: GECAM-B detection of a bright burst
Chao Zheng, Shaolin Xiong, report on behalf of the GECAM team:
GECAM-B was triggered in-flight by a likely long burst, GRB 231129C,
at 2023-11-29T19:10:18.200 UTC, which was also observed by
Fermi/GBM (Fermi/GBM team, GCN 35217 & 35227) and MAXI/GSC
(Y. Kawakubo et al., GCN 35223) and CALET (Y. Shimizu et al., GCN 35228)
and AstroSat (G. Waratkar et al., GCN 35230).
According to the realtime alert data of GECAM-B, this burst mainly consists
of a bright pulse with a total duration (T90) of about ~15 sec (20-1000 keV).
The GECAM light curve could be found here:
http://twiki.ihep.ac.cn/pub/HXMT/GRBList/GRB231129C_LC.png
GECAM location is consistent with that of MAXI/GSC within the error.
We note that these results are based on realtime alert data and thus very preliminary.
Refined analysis will be reported later.
Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B)
launched in Dec. 2020. As the third member of GECAM constellation,
GECAM-C was launched onboard SATech-01 experimental satellite in July 2022.
GECAM mission is funded by the Chinese Academy of Sciences (CAS).
View this GCN Circular online at https://gcn.nasa.gov/circulars/35231.
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TITLE: GCN CIRCULAR
NUMBER: 35230
SUBJECT: GRB 231129C: AstroSat CZTI detection
DATE: 23/11/30 09:47:31 GMT
FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in>
G. Waratkar (IITB), P. K. Navaneeth (IUCAA), 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 an extremely bright long-duration GRB 231129C which was also detected by Fermi-GBM (Fermi GBM team, GCN Circ. 35217), MAXI/GSC (Kawakubo et al., GCN Circ. 35223), and CALET (Shimizu et al., GCN Circ. 35228).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. Based on the orientation of the CZTI, the burst saturated two quadrants (A, B out of four). We report two versions of our analysis of CZT data: one from two unsaturated quadrants (C, D), and the other for all four quadrants by including unsaturated data segments from A, B.
For the two unsaturated quadrants C and D, the light curve peaks at 2023-11-29 19:10:18 UTC. The measured peak count rate associated with the burst is 1189 (+237, -8) counts/s above the background in the combined CD data, with a total of 3838 (+150, -144) counts. The local mean background count rate was 155.1 (+3.7, -5.9) counts/s. Using cumulative rates, we measure a T90 of 5.1 (+0.2, -0.2) s in these two quadrants.
Using unsaturated data segments from all four quadrants, we report that burst duration was 6.7 (+0.2, -0.2) s. We also report a minimum peak count rate of 4164.2 (+328.9, -329.3) counts/s at a local mean background count rate of 334.8 (+6.7, -7.4) count/s, with a total of at least 8061 (+195, -236) counts. In the preliminary analysis, we find 1362 Compton events associated with this event in all four quadrants.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2023-11-29 19:10:18.69 UTC. The measured peak count rate is 4408 (+125, -126) counts/s above the background in the combined Veto data of all quadrants, with a total of 18860 (+406, - 410) counts. The local mean background count rate was 1511.3 (+6.5, -7.7) counts/s. We measure a T90 of 5.5 (+0.2, -0.2) 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=grb
View this GCN Circular online at https://gcn.nasa.gov/circulars/35230.
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TITLE: GCN CIRCULAR
NUMBER: 35229
SUBJECT: GRB 231129C: iTelescope OT retraction
DATE: 23/11/30 07:25:40 GMT
FROM: Filipp Dmitrievich Romanov at Amateur astronomer <filipp.romanov.27.04.1997(a)gmail.com>
Retraction of GCN #35226. I did not have access to a computer to check
in time that this object was a star with a high proper motion. I
initially compared my images with archival images from the DSS Plate
Finder, but now I have determined that AT 2023yph is a star
#4631003097698452224 from the Gaia DR3.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35229.
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TITLE: GCN CIRCULAR
NUMBER: 35228
SUBJECT: GRB 231129C: CALET Gamma-Ray Burst Monitor detection
DATE: 23/11/30 06:11:11 GMT
FROM: Yuta Kawakubo at Louisiana State University <kawakubo1(a)lsu.edu>
Y. Shimizu (Kanagawa U), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
T. Tamura (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 GRB 231129C (Fermi GBM Final Real-time Localization: Fermi GBM team,
GCN Circ. 35217; Fermi GBM detection: Sharma at al., GCN Circ. 35221; BALROG
localization: Preis et al., GCN Circ 35222; MAXI/GSC detection: Kawakubo et al.,
GCN Circ. 35223) triggered the CALET Gamma-ray Burst Monitor (CGBM) at
19:10:15.03 UTC on 29 November 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1385320118/index.html).
The burst signal was seen by all CGBM detectors.
The burst light curve shows a single pulse that starts
at T+3.1 sec, peaks at T+4.7 sec, and ends at T+8.9 sec.
The T90 and T50 durations measured by the SGM data are 4.7 +/- 0.4 sec
and 2.2 +/- 0.2 sec (40-1000 keV), respectively.
The ground-processed light curve is available at
http://cgbm.calet.jp/cgbm_trigger/ground/1385320118/index.html
The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35228.
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TITLE: GCN CIRCULAR
NUMBER: 35227
SUBJECT: GRB 231129C: Fermi GBM Observation of a very bright GRB
DATE: 23/11/30 04:57:42 GMT
FROM: Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma(a)nasa.gov>
V. Sharma (NASA-GSFC/UMBC), C. Fletcher (USRA) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 19:10:18.11 UT on 29 November 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 231129C (trigger 722977823/231129799), which was also detected by MAXI/GSC (Y. Kawakubo et al. 2023, GCN 35223). The Fermi GBM Final Real-time Localization is reported (GCN 35221, GCN 35217).
The angle from the Fermi LAT boresight at the GBM trigger time is 50 degrees.
The GBM light curve shows a very bright, single pulse starting from about T0+0 s to T0+15 s. The calculated duration (T90) is about 6 s (50-300 keV). The time-averaged spectrum from T0+0 s to T0+7 s can be fit by a Band function with Epeak = 215 +/- 2 keV, alpha = -0.11 +/- 0.01, and beta = -2.79 +/- 0.03.
The event fluence (10-1000 keV) in this time interval is (8.41 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.8 s in the 10-1000 keV band is 102 +/- 1 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/"
View this GCN Circular online at https://gcn.nasa.gov/circulars/35227.
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TITLE: GCN CIRCULAR
NUMBER: 35226
SUBJECT: GRB 231129C: iTelescope likely optical afterglow AT 2023yph discovery
DATE: 23/11/30 04:57:40 GMT
FROM: Filipp Dmitrievich Romanov at Amateur astronomer <filipp.romanov.27.04.1997(a)gmail.com>
I observed the field of GRB 231129C (Fermi GBM Team, GCN Circ. 35217)
near the MAXI (GCN Circ. 35223) sky region using remote telescope T72
(0.51-m f/6.8 Corrected Dall-Kirkham + CCD) of iTelescope.Net in Deep
Sky Chile at Rio Hurtado Valley, Chile. 9 images (with exposures 300
seconds, BINx1) were obtained with Ic filter with midtime 02:27 UT. I
detected an uncataloged source with position 00 49 17.780 -81 29 45.83
and measured its brightness near +18 mag. Magnitude was not corrected
for Galactic extinction. I am guessing this is an optical afterglow of
GRB 231129C. Now it is AT 2023yph
https://www.wis-tns.org/object/2023yph
F. D. Romanov (AAVSO).
View this GCN Circular online at https://gcn.nasa.gov/circulars/35226.
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TITLE: GCN CIRCULAR
NUMBER: 35225
SUBJECT: GRB 231129C: Tiled Swift observations
DATE: 23/11/30 00:33:31 GMT
FROM: Phil Evans at U of Leicester <pae9(a)star.le.ac.uk>
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a series of observations, tiled on the sky, of the
Fermi/GBM GRB 231129C. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00117
Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the Fermi/GBM event is high: 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.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35225.
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TITLE: GCN CIRCULAR
NUMBER: 35224
SUBJECT: GRB 231127A: GRBAlpha detection
DATE: 23/11/29 22:31:48 GMT
FROM: Marianna Dafčíková at Masaryk University <500025(a)mail.muni.cz>
M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), yyT. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.
The long-duration GRB 231127A (AstroSat detection: GCN 35197; CALET/CGBM detection: GCN 35200; Konus/Wind trigger at 2023-11-27 05:14:24.085 UT; INTEGRAL/SPI-ACS peak detection at 2023-11-27 ~05:14:20 UT) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; arXiv:2302.10048).
The detection was confirmed at the peak time 2023-11-27 05:14:21 UTC. The T90 duration measured by GRBAlpha is 6 s and the overall significance during T90 reaches 14 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB231127A_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35224.
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TITLE: GCN CIRCULAR
NUMBER: 35223
SUBJECT: GRB 231129C: MAXI/GSC detection
DATE: 23/11/29 22:19:44 GMT
FROM: kurihara(a)ac.jaxa.jp
Y. Kawakubo (LSU),
H. Negoro, M. Nakajima, K. Kobayashi, M. Tanaka, Y. Soejima, Y. Kudo (Nihon U.),
T. Mihara, T. Kawamuro, S. Yamada, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN),
T. Sakamoto, M. Serino, S. Sugita, H. Hiramatsu, H. Nishikawa, A. Yoshida (AGU),
Y. Tsuboi, S. Urabe, S. Nawa, N. Nemoto, E.Goto (Chuo U.),
M. Shidatsu (Ehime U.),
I. Takahashi, M. Niwano, S. Sato, N. Higuchi, Y. Yatsu (Tokyo Tech),
S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, T. Kurihara (JAXA),
Y. Ueda, K. Setoguchi, T. Yoshitake, Y. Nakatani, Y. Okada (Kyoto U.),
M. Yamauchi, Y. Hagiwara, Y. Umeki, Y. Otsuki (Miyazaki U.),
K. Yamaoka (Nagoya U.),
M. Sugizaki (NAOC),
W. Iwakiri (Chiba U.)
report on behalf of the MAXI team:
The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient
source at 2023/11/29 19:10:18 UT.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (11.910 deg, -81.636 deg) = (00 47 38, -81 38 09) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.09 deg and 0.07 deg, respectively.
The roll angle of long axis from the north direction is 90.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 1355 +- 82 mCrab
(4.0-10.0keV, 1 sigma error).
Without assumptions on the source constancy, we obtain a rectangular error
box for the transient source with the following corners:
(R.A., Dec) = (12.351, -81.744) deg = (00 49 24, -81 44 38) (J2000)
(R.A., Dec) = (11.353, -81.663) deg = (00 45 24, -81 39 46) (J2000)
(R.A., Dec) = (12.374, -81.394) deg = (00 49 29, -81 23 38) (J2000)
(R.A., Dec) = (13.350, -81.472) deg = (00 53 23, -81 28 19) (J2000)
There was no significant excess flux in the previous transit at 17:37 UT
with an upper limit of 20 mCrab for each.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35223.
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TITLE: GCN CIRCULAR
NUMBER: 35222
SUBJECT: GRB 231129C: BALROG localization (Fermi Trigger / GRB 231129799)
DATE: 23/11/29 22:08:45 GMT
FROM: Jochen Greiner at MPE <jcgrog(a)mpe.mpg.de>
T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
at 19:10:18 on 29 Nov. 2023 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) = 7.8+/-1.7 deg
Decl.(2000.0) = -81.3+/-0.3 deg
We estimate an additional systematic error of 2 deg.
Further details are available at:
https://grb.mpe.mpg.de/grb/GRB231129799/
The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB231129799/healpix
The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB231129799/json
View this GCN Circular online at https://gcn.nasa.gov/circulars/35222.
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