TITLE: GCN CIRCULAR
NUMBER: 35246
SUBJECT: GRB 231128A: VZLUSAT-2 detection
DATE: 23/12/01 16:00:49 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 (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 231128A (Fermi/GBM detection: GCN 35206) 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 the GRB detector unit no. 1. The detection was confirmed at the peak time 2023-11-28 11:44:15 UTC. The T90 duration is 24 s and the significance during T90 reaches 9.7 sigma.
The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB231128A_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.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35246.
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TITLE: GCN CIRCULAR
NUMBER: 35245
SUBJECT: Optical transient in the field of Messier 31, likely a new blazar: back to bright state
DATE: 23/12/01 12:07:03 GMT
FROM: Gianluca Masi at Virtual Telescope Project <gianluca(a)bellatrixobservatory.org>
We report that the new blazar candidate in the field of Messier 31 (NGC 224) reported by G. Masi in GCN 34819 is again on bright state, found at R=17.9 on 29.72 Nov. 2023.
The optical source, which discovery is described in the GCN circular mentioned above, has been brighter than R=19.0 since at least 10 Aug. 2023, showing an almost 1.5 mag. large amplitude in its light curve.
Extensive, R-band photometry since 10 Aug. 2023 is available at the following web address:
https://www.virtualtelescope.eu/2023/08/16/discovery-of-variability-of-the-…
Multi-wavelength observations are strongly encouraged.
Gianluca Masi
Virtual Telescope Project
View this GCN Circular online at https://gcn.nasa.gov/circulars/35245.
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TITLE: GCN CIRCULAR
NUMBER: 35244
SUBJECT: GRB 231129C: AGILE detection
DATE: 23/12/01 11:28:51 GMT
FROM: Gabriele Panebianco <gabriele.panebianco(a)inaf.it>
G. Panebianco (Univ. Bologna - INAF/OAS Bologna), A. Bulgarelli (INAF/OAS Bologna),
C. Pittori, F. Verrecchia (SSDC, and INAF/OAR),
M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, L. Foffano, G. Piano (INAF/IAPS),
L. Baroncelli, A. Ciabattoni, A. Di Piano, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna),
F. Lucarelli (SSDC, and INAF/OAR), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
M. Pilia, A. Trois (INAF/OA-Cagliari),
F. Longo (Univ. Trieste, and INFN Trieste), A. Ursi (ASI and INAF/IAPS),
I. Donnarumma, E. Menegoni (ASI), A. Giuliani (INAF/IASF-Mi),
P.W. Cattaneo (INFN Pavia), F. Cutrona (Univ. Milano Bicocca) and P. Tempesta (TeleSpazio)
report on behalf of the AGILE Team:
The AGILE satellite detected the bright and long GRB 231129C at T0 = 2023-11-29 19:10:18 s (UTC),
reported by Fermi (GCNs #35217, #35221, #35227, #35238), BALROG (GCN #35222),
MAXI/GSC (GCN #35223), Swift (GCNs #35225, #35234, #35242), CALET (GCN #35228),
AstroSAT CZTI (GCN #35230), GECAM-B (GCN #35231), Glowbug (GCN #35235),
GRBAlpha (GCN #35236), MASTER OT (#35240).
The burst is clearly visible in the AGILE scientific ratemeters of the
MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV)
detectors. The pulse lasted about 10 s and it released a total number
of 7648 counts in the MCAL detector (above a background rate of 525 Hz)
and 49403 counts in the AC-Top detector (above a background rate of 2900 Hz).
The AGILE ratemeters light curves can be found at
http://www.agilescienceapp.it/notices/GRB231129C_AGILE_RM_ND.png .
At the detection time the GRB location was occulted by the Earth for the AGILE GRID instrument.
Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices
can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html
View this GCN Circular online at https://gcn.nasa.gov/circulars/35244.
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TITLE: GCN CIRCULAR
NUMBER: 35243
SUBJECT: GRB 231129A : MITSuME Akeno optical upper limits
DATE: 23/12/01 09:27:23 GMT
FROM: Narikazu Higuchi at Tokyo Tech <higuchi(a)hp.phys.titech.ac.jp>
N. Higuchi, I. Takahashi, M. Sasada, M. Niwano, S. Sato, S. Hayatsu, H. Takei, H. Seki, Y. Yatsu and N. Kawai (Tokyo Tech) report on behalf of the MITSuME collaboration:
We observed the field of GRB 231129A (Gropp et al. GCN 35208 and Mereghetti et al. GCN 35209) with the optical three-color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50-cm telescope Akeno.
The observation started at 2023-11-29 08:01:47 UT (2.93 hours after the Swift/BAT and INTEGRAL/IBAS trigger). We stacked the images with good conditions. We did not detect any uncatalogued sources within the enhanced Swift/XRT error region (Goad et al. GCN 35220). We obtained the 5-sigma limits of the stacked images as follows.
T0+[hour] | MID-UT | T-EXP[sec] | 5-sigma limits
------------------------------------------------------------------------------------------------
4.50 | 2023-11-29 09:35:41 | 7140 | g'>19.4, Rc>19.0, Ic>18.4
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the trigger
T-EXP: Total Exposure time
We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1 g, r and i bands were converted to our g', Rc and Ic band magnitudes following 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).
View this GCN Circular online at https://gcn.nasa.gov/circulars/35243.
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TITLE: GCN CIRCULAR
NUMBER: 35242
SUBJECT: GRB 231129C: Swift/BAT-GUANO localization of a burst outside the coded FOV
DATE: 23/12/01 03:52:27 GMT
FROM: Jimmy DeLaunay at Penn State <delauj2(a)gmail.com>
James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report:
Swift/BAT did not localize GRB 231129C onboard (T0: 2023-11-29T19:10:15.02 UTC, CALET trig 1385320118 / GCN 35223 Fermi GBM trig 722460326 / GCN 35221, GECAM trig 238 / GCN 35231, MAXI-GSC GCN 35223, AstroSat GCN 35230, Glowbug GCN 35235, GRBAlpha GCN 35236, Fermi LAT GCN 35238)
The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).
Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 90 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.
The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 92.6 in a 4.096 s analysis time bin, starting at T0 + 3.072 s.
NITRATES results are consistent with a burst coming from outside the FOV, with DeltaLLHOut of -477.
See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.
A preliminary localization of this GRB was performed, finding a best fit position of
RA, Dec = 301.3, -80.4 deg
With a roughly circular 90% error radius of 11.1 deg
Calibration of systematics for localizations outside the coded field of view is not yet complete.
GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches.
A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/
View this GCN Circular online at https://gcn.nasa.gov/circulars/35242.
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