GRB230426A

This page lists all entries on GRB230426A in GRBweb

Summary Fermi GBM IPN GCN 33684 GCN 33686 GCN 33689 GCN 33691 GCN 33702

Summary table
Variable Value Source
GRB_name_Fermi GRB230426853
T0 20:28:59 UTC GCN_circulars,Fermi GBM final loc
ra 37.8965° GCN_circulars,Optical
decl -79.3511° GCN_circulars,Optical
T90 25.856 s Fermi_GBM
T90_error 0.724 s Fermi_GBM
T90_start 20:29:08.670 UTC Fermi_GBM
fluence 5.23e-05 erg/cm² Fermi_GBM
fluence_error 6.74e-08 erg/cm² Fermi_GBM
T100 35.526 s
GBM_located False
mjd 60060.85346064815 GCN_circulars,Fermi GBM final loc
Fermi GBM table
GRB_name_Fermi GRB230426853
trigger_name bn230426853
ra 38.5300°
decl -82.4000°
pos_error 2.47e+00°
datum 2023-04-26
t_trigger 20:28:59.966 UTC
T90 25.856 s
T90_error 0.724 s
T90_start 20:29:08.670 UTC
fluence 5.23e-05 erg/cm²
fluence_error 6.74e-08 erg/cm²
flux_1024 6.66e+01 erg/cm²/s
flux_1024_error 6.51e-01 erg/cm²/s
flux_1024_time 2.29e+01 erg/cm²/s
flux_64 7.28e+01 erg/cm²/s
flux_64_error 2.68e+00 erg/cm²/s
IPN table
GRB_name GRB230426A
ra 37.8958°
decl -79.3500°
pos_error 3.00e+00°
GCN 33684 table
GRB_name GRB230426A
GCN_number 33684
Detection_method Fermi GBM final loc
t_trigger 20:28:59 UTC
ra 38.5000°
decl -82.4000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 33684 SUBJECT: GRB 230426A: Fermi GBM Final Real-time Localization DATE: 23/04/26 20:39:19 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 20:28:59 UT on 26 Apr 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230426A (trigger 704233744.96626 / 230426853). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 38.5, Dec = -82.4 (J2000 degrees, equivalent to J2000 02h 34m, -82d 24'), with a statistical uncertainty of 1.0 degrees. The angle from the Fermi LAT boresight is 49.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230426853/quicklook/glg_skymap_all_bn230426853.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230426853/quicklook/glg_healpix_all_bn230426853.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230426853/quicklook/glg_lc_medres34_bn230426853.gif
GCN 33686 table
GRB_name GRB230426A
GCN_number 33686
Detection_method AstroSat CZTI
Circular_text TITLE: GCN CIRCULAR NUMBER: 33686 SUBJECT: GRB 230426A: AstroSat CZTI detection DATE: 23/04/27 05:36:14 GMT FROM: Gaurav Waratkar at IIT Bombay P K. Navaneeth (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 ML pipeline (Abraham et al., 2021, MNRAS, 504, 3084) and the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a bright long GRB 230426A which was also detected by Fermi (Fermi GBM Team, GCN Circ. 33684). The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2023-04-26 20:29:23.50 UTC. The measured peak count rate associated with the burst is 1773 (+77, -81) counts/s above the background in the combined data of all quadrants, with a total of 14876 (+653, -615) counts. The local mean background count rate was 454 (+2, -3) counts/s. Using cumulative rates, we measure a T90 of 23 (+3, -2) s. In the preliminary analysis, we find 1069 Compton events associated with this event. The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2023-04-26 20:29:23.50 UTC. The measured peak count rate associated with the burst is 1179 (+82, -77) counts/s above the background in the combined data of all quadrants, with a total of 8609 (+655, -665) counts. The local mean background count rate was 1491 (+4, -5) counts/s. We measure a T90 of 18 (+5, -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
GCN 33689 table
GRB_name GRB230426A
GCN_number 33689
Detection_method Fermi GBM Det
t_trigger 20:28:59.970 UTC
ra 38.5300°
decl -82.4000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 33689 SUBJECT: GRB 230426A: Fermi GBM Detection DATE: 23/04/27 15:03:34 GMT FROM: Joshua Wood at NASA/MSFC J. Wood (NASA/MSFC) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 20:28:59.97 UT on 26 April 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230426A (trigger 704233744/230426853) which was also detected by AstroSat CZTI (P K. Navaneeth et al. 2023, GCN 33686). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 38.53, Dec = -82.40 (J2000 degrees, equivalent to J2000 2h 34m, -82d 24'), with a statistical uncertainty of 1.00 degrees. (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a mixture of two Gaussians, one with a radius of 1.8 degrees (52% contribution) and one with a radius of 4.1 degrees (47% contribution) [A. Goldstein et al. 2020, ApJ, 895, 1]). The angle from the Fermi LAT boresight is 49 degrees. The GBM light curve consists of multiple pulses with a duration (T90) of about 25.9 s (50-300 keV). The time-averaged spectrum from T0+8.2 to T0+35.8 s is best fit by a Band function with Epeak = 77 +/- 2 keV, alpha = -1.34 +/- 0.02, and beta = -2.38 +/- 0.03. The event fluence (10-1000 keV) in this time interval is (5.21 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+23 s in the 10-1000 keV band is 66.6 +/- 0.7 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 33691 table
GRB_name GRB230426A
GCN_number 33691
Detection_method Optical
ra 37.8965°
decl -79.3511°
Circular_text TITLE: GCN CIRCULAR NUMBER: 33691 SUBJECT: GRB 230426A: MASTER OT J023135.16-792104.8 optical counterpart discovery DATE: 23/04/27 17:28:36 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Lipunov (Lomonosov MSU), D.A.H.Buckley (SAAO), Ya.Kechin, A.Chasovnikov, A.Kuznetsov, N.Tiurina, P.Balanutsa, O.Gress, E.Gorbovskoy, G.Antipov, K.Zhirkov, D.Vlasenko, V.Senik, V.Topolev, Yu.Tselik, Siyu Wu (Lomonosov Moscow State University, SAI, Physics Department), C.Francile, F. Podesta, C.Lopez, R. Podesta (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), N.M.Budnev, O.Ershova (ISU,API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University), K.Vetrov, V.Shumkov, T.Pogrosheva MASTER-SAAO robotic telescope (Global MASTER Net http://observ.pereplet.ru,Lipunov et al., 2010, Advances in Astronomy, v.2010, 30L) located in South African Astronomical Observatory started (Lipunov et al. GCN 33685) inspect of the FERMI GRB230426.85 (trigger 704233744, Wood et al. GCN 33689, Ttrigger 20:28:59.97UT) errorbox 4359 sec after notice time (4391 sec after trigger time) at 2023-04-26 21:42:11UT with upper limit up to 19.5m, see our cover map https://master.sai.msu.ru/site/master2/observ.php?id=2212931 MASTER OT J023135.16-792104.8 - optical counterpart of GRB 230426A discovery 2023gwu MASTER-SAAO auto-detection system found optical counterpart of GRB 230426.85 at R.A.,Dec(2000) = 02h 31m 35.16s , -79d 21m 04s.8 with unfiltered m_OT=17.4 at 2023-04-26 21:56:50UT and with optical decay at 10 images https://www.wis-tns.org/object/2023gwu . There is no any sources in VIZIER database, no any objects in MPC at this time and no OT in MASTER database since Dec.2014. We used reference image on 2018-08-18.99148 UT with unfiltered mlim=20.6m. Analysis will be continued. Deep photometry and spectral observations are required. The message may be cited.
GCN 33702 table
GRB_name GRB230426A
GCN_number 33702
Detection_method AstroSat CZTI
Circular_text TITLE: GCN CIRCULAR NUMBER: 33702 SUBJECT: GRB 230426A: VZLUSAT-2 detection DATE: 23/04/28 10:57:54 GMT FROM: Marianna Dafčíková at Masaryk University <500025@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 230426A (Fermi/GBM detection: GCN 33684; Astrosat/CZTI detection: GCN 33686; INTGERAL/SPI-ACS detection at 2023-04-26 20:29:23 UT) was detected by the GRB detectors on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/). The data acquisition was performed by the GRB detector units no. 0 and no. 1. The detection was confirmed at the peak time 2023-04-26 20:29:21 UTC. The T90 duration measured by VZLUSAT-2 is 35 s (25 s) and the significance during T90 reaches 18 sigma (68 sigma) for detector unit no. 0 (no. 1). The light curve obtained by VZLUSAT-2 is available here: https://vzlusat2.konkoly.hu/static/share/GRB230426A_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.