TITLE: GCN CIRCULAR
NUMBER: 35635
SUBJECT: GRB 240123C: AstroSat CZTI detection
DATE: 24/01/26 08:25:49 GMT
FROM: Gaurav Waratkar at IIT Bombay <gauravwaratkar(a)iitb.ac.in>
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 short-duration GRB 240123C which was also detected by Konus-Wind, INTEGRAL (SPI-ACS), Swift (BAT), and Mars-Odyssey (HEND) (A.S. Kozyre, GCN Circ. 35627).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve peaks at 2024-01-23 23:12:36.55 UTC. The measured peak count rate associated with the burst is 1936 (+240, -237) counts/s above the background in the combined data of all quadrants, with a total of 798 (+116, -73) counts. The local mean background count rate was 312 (+8, -15) counts/s. Using cumulative rates, we measure a T90 of 1.4 (+0.61, -0.38) s.
The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2024-01-23 23:12:36.81 UTC. The measured peak count rate associated with the burst is 560 (+70, -77) counts/s above the background in the combined data of all quadrants, with a total of 1166 (+263, -284) counts. The local mean background count rate was 1288 (+11, -11) counts/s. Due to the intrinsic 1 s binning of veto data, we cannot reliably estimate a T90 from it.
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/35635.
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TITLE: GCN CIRCULAR
NUMBER: 35633
SUBJECT: GRB240122A: PRIME near infrared detection
DATE: 24/01/25 20:05:40 GMT
FROM: Joe Durbak at UMD <gcn.joedurbak(a)gmail.com>
O. Guiffreda (UMD), J. Durbak (UMD), A. S. Kutyrev (NASA/GSFC), E. Troja (U Rome), K. De (MIT), S. B. Cenko (NASA/GSFC)
Following the MAXI/GSC detection (Negoro et al. GCN 35593), GOTO optical candidate GOTO24eu/AT2024apy (Kumar et al. GCN 35596), and the Swift afterglow detection (Ambrosi et al. GCN 35600), we observed the transient field using J and H filters with PRIME ~1.5 days after MAXI/GSC detection.
At the position of the optical counterpart detected by GOTO, we detect an uncatalogued source in both J and H bands. Using nearby 2MASS stars for preliminary calibration we derive the following magnitudes, not corrected for Galactic extinction:
Filter | Mag(AB) | SNR | Seeing | Total exposure time (s)
-------|----------------|-----|--------|-------------------------
J | 21.02 +/- 0.20 | 6.3 | 1.373” | 1802
H | 20.90 +/- 0.21 | 6.1 | 1.480” | 1544
PRIME is a 1.8m telescope with 1.56 square degree FOV (0.5 arcsec/pixel) located in Sutherland, South Africa.
Further observations are planned.
We thank the Osaka University observers at PRIME and the staff at SAAO for their support with these observations.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35633.
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TITLE: GCN CIRCULAR
NUMBER: 35632
SUBJECT: GRB 240123B: Fermi GBM Observation
DATE: 24/01/25 19:45:45 GMT
FROM: Lorenzo Scotton at UAH <lscottongcn(a)outlook.com>
L. Scotton (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:
"At 17:48:03.22 UT on 23 January 2024, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 240123B (trigger 727724888/240123742).
which was also detected by Swift/BAT-GUANO (Ronchini et al. 2024, GCN 35629).
The Fermi GBM Final Real-time Localization was reported in GCN 35608.
The angle from the Fermi LAT boresight is 51 degrees.
The GBM light curve consists of a single emission episode with a duration (T90)
of about 12 s (50-300 keV). The time-averaged spectrum
from T0-0.5 to T0+11.5 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.6 +/- 0.2 and the cutoff energy,
parameterized as Epeak, is 250 +/- 30 keV.
The event fluence (10-1000 keV) in this time interval is
(2.6 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+4.9 s in the 10-1000 keV band is 2.4 +/- 0.2 ph/s/cm^2.
A Band function fits the spectrum equally well
with Epeak= 130 +/- 30 keV, alpha = 0.1 +/- 0.4 and beta = -1.9 +/- 0.1.
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/35632.
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TITLE: GCN CIRCULAR
NUMBER: 35631
SUBJECT: GRB 240123A: Glowbug gamma-ray detection
DATE: 24/01/25 18:11:33 GMT
FROM: C.C. Cheung at Naval Research Lab <Teddy.Cheung(a)nrl.navy.mil>
C.C. Cheung, M. Kerr, J.E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of GRB 240123A, which was also detected by Swift/BAT (GCN 35602, 35622), Fermi/GBM (GCN 35610), and GRBAlpha (GCN 35628).
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-01-23 11:05:48.840 with a duration of 6.1 s and a total significance of about 12.2 sigma. The light curve comprises a single peak.
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a photon index dN/dE~E^x of x=-0.4 and a cutoff energy ("Epeak") of 719 keV. The modeled 10-10000 keV fluence is 1.3e-06 erg/cm^2.
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS. The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
Distribution Statement A: Approved for public release. Distribution is unlimited.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35631.
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TITLE: GCN CIRCULAR
NUMBER: 35630
SUBJECT: GRB 240125A (short): Glowbug gamma-ray detection
DATE: 24/01/25 18:08:11 GMT
FROM: C.C. Cheung at Naval Research Lab <Teddy.Cheung(a)nrl.navy.mil>
GRB 240125A (short): Glowbug gamma-ray detection
C.C. Cheung, M. Kerr, J.E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
The Glowbug gamma-ray telescope [1,2], operating on the International Space Station, reports the detection of the short GRB 240125A, which was also detected by CALET/CGBM (Trigger 1390210300).
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2024-01-25 09:34:59.200 with a duration of 1.28 s and a total significance of about 51.2 sigma. The light curve comprises a triple-peaked structure.
Using a standard power-law function with an exponential high-energy cutoff [3] to model the emission over this duration results in a photon index dN/dE~E^x of x=0.8 and a cutoff energy ("Epeak") of 705 keV. The modeled 10-10000 keV fluence is 3.2e-06 erg/cm^2.
The best-fit localization is RA, Decl. (J2000, deg) = 153.4, 48.7 with a radius of 9.3 deg (95% confidence), with a highly uncertain systematic uncertainty.
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS. The detector comprises 12 large-area (15 cm x 15 cm) CsI:Tl panels covering the surface of a half cube, and two hexagonal (5-cm diameter, 10-cm length) CLLB scintillators, giving it a large field of view (instantaneous FoV ~2/3 sky) over a wide energy band of 50 keV to >2 MeV.
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Goldstein, A. et al. 2020, ApJ 895, 40, arXiv :1909.03006
Distribution Statement A: Approved for public release. Distribution is unlimited.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35630.
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TITLE: GCN CIRCULAR
NUMBER: 35629
SUBJECT: GRB 240123B: Swift/BAT-GUANO detection of a long burst
DATE: 24/01/25 16:01:37 GMT
FROM: Samuele Ronchini at PSU <sjs8171(a)psu.edu>
Samuele Ronchini (PSU), James DeLaunay (PSU), Gayathri Raman (PSU), Aaron Tohuvavohu (U Toronto), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report:
Swift/BAT did not localize GRB 240123B onboard (T0: 2024-01-23T17:48:03.22 UTC, Fermi GCN 35608).
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 200 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 15.5 in a 8.192 s analysis time bin, starting at T0 - 2.05 s.
NITRATES results, independently, are ambiguous with respect to whether this burst originates from in or outside the BAT coded FOV, with a DeltaLLHOut of 2.75.
See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.
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/35629.
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TITLE: GCN CIRCULAR
NUMBER: 35628
SUBJECT: GRB 240123A: GRBAlpha detection
DATE: 24/01/25 14:21:21 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.), T. 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 240123A (Swift/BAT detection: GCN 35602; Fermi/GBM detection: GCN 35610; INTEGRAL/SPI-ACS peak detection at 2024-01-23 ~11:05:47) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; arXiv:2302.10048).
The subthreshold detection was confirmed at the peak time 2024-01-23 11:05:49 UTC. The T90 duration measured by GRBAlpha is 8 s and the overall significance during T90 reaches 3.5 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB240123A_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/35628.
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TITLE: GCN CIRCULAR
NUMBER: 35627
SUBJECT: IPN triangulation of GRB 240123C (short)
DATE: 24/01/25 11:35:17 GMT
FROM: Anna Ridnaia at Ioffe Institute <ridnaia(a)mail.ioffe.ru>
A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,
A. Ridnaia, D. Frederiks, D. Svinkin, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,
E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team,
and
W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:
The short-duration GRB 240123C
was detected by Konus-Wind, INTEGRAL (SPI-ACS),
Swift (BAT), and Mars-Odyssey (HEND)
at about 83553 s UT (23:12:33).
The burst was outside the coded field of view of the BAT.
We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
RA(2000), deg Dec(2000), deg
---------------------------------------------
Center:
244.077 (16h 16m 19s) -58.857 (-58d 51' 25")
Corners:
240.883 (16h 03m 32s) -55.715 (-55d 42' 55")
241.066 (16h 04m 16s) -56.037 (-56d 02' 14")
248.066 (16h 32m 16s) -61.657 (-61d 39' 24")
247.747 (16h 30m 59s) -61.386 (-61d 23' 11")
---------------------------------------------
The error box area is 1219 sq. arcmin, and its maximum
dimension is 7.0 deg (the minimum one is 3 arcmin).
The Sun distance was 58 deg.
This localization may be improved.
A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB240123_T83553/IPN
The Konus-Wind time history and spectrum will be given
in a forthcoming GCN Circular.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35627.
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TITLE: GCN CIRCULAR
NUMBER: 35626
SUBJECT: Swift trigger 1210856 is not astrophysical
DATE: 24/01/25 11:25:42 GMT
FROM: Boris Sbarufatti at INAF-OAB <boris.sbarufatti(a)inaf.it>
N. J. Klingler (GSFC/UMBC/CRESSTII), K. L. Page (U Leicester) and
B. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift
Observatory Team:
Swift trigger 1210856 was also caused by a star track loss-of-lock
event, and is not an interesting event itself.
View this GCN Circular online at https://gcn.nasa.gov/circulars/35626.
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