GRB230827B

This page lists all entries on GRB230827B in GRBweb

Summary Fermi GBM IPN GCN 34584 GCN 34585 GCN 34593 GCN 34596 GCN 34601 GCN 34604

Summary table
Variable Value Source
GRB_name_Fermi GRB230827256
T0 6:08:30.730 UTC GCN_circulars,Fermi GBM Det
ra 299.6375° IPN
decl 54.4667° IPN
pos_error 5.00e-02° IPN
T90 11.005 s Fermi_GBM
T90_error 2.318 s Fermi_GBM
T90_start 6:08:30.737 UTC Fermi_GBM
fluence 1.05e-05 erg/cm² Fermi_GBM
fluence_error 1.47e-07 erg/cm² Fermi_GBM
T100 11.012 s
GBM_located False
mjd 60183.25591122685 GCN_circulars,Fermi GBM Det
Fermi GBM table
GRB_name_Fermi GRB230827256
trigger_name bn230827256
ra 299.3200°
decl 56.4700°
datum 2023-08-27
t_trigger 6:08:30.734 UTC
T90 11.005 s
T90_error 2.318 s
T90_start 6:08:30.737 UTC
fluence 1.05e-05 erg/cm²
fluence_error 1.47e-07 erg/cm²
flux_1024 1.64e+01 erg/cm²/s
flux_1024_error 8.87e-01 erg/cm²/s
flux_1024_time 4.74e+00 erg/cm²/s
flux_64 2.18e+01 erg/cm²/s
flux_64_error 3.49e+00 erg/cm²/s
IPN table
GRB_name GRB230827B
ra 299.6375°
decl 54.4667°
pos_error 5.00e-02°
GCN 34584 table
GRB_name GRB230827B
GCN_number 34584
Detection_method Fermi GBM Det
t_trigger 6:08:30.730 UTC
ra 299.3200°
decl 56.4700°
Circular_text TITLE: GCN CIRCULAR NUMBER: 34584 SUBJECT: GRB 230827B / GRB 230827256: Fermi GBM Observation DATE: 23/08/28 13:52:48 GMT FROM: rachel.hamburg@ijclab.in2p3.fr R. Hamburg (CNRS/IJCLab) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 06:08:30.73 UT on 27 August 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230827B (trigger 714809315/230827256). The optical afterglow of GRB 230827B was also detected by ZTF (GCN 34574), GIT (GCN 34576), and AKO (GCN 34579). The location of the afterglow is consistent with the GBM on-ground calculated location, which is RA = 299.32, Dec = +56.47 (J2000 degrees, equivalent to J2000 19h 57m 17s, +56d 28' 12"), with a statistical uncertainty of 2.17 degrees. The angle from the Fermi LAT boresight is 140 degrees. The GBM light curve shows a multi-peaked lightcurve with a duration (T90) of about 11 s (50-300 keV). The time-averaged spectrum from T0+0.002 to T0+10.240 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.37 +/- 0.05 and the cutoff energy, parameterized as Epeak, is 352 +/- 52 keV. A Band function fits the spectrum equally well with Epeak= 256 +/- 51 keV, alpha = -1.28 +/- 0.08 and beta = -2.2 +/- 0.2. The event fluence (10-1000 keV) in this time interval is (1.08 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+4.7 s in the 10-1000 keV band is 16.4 +/- 0.9 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 34585 table
GRB_name GRB230827B
GCN_number 34585
Detection_method Fermi GBM Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 34585 SUBJECT: GRB 230827B: VZLUSAT-2 detection DATE: 23/08/28 17:13:25 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 230827B (Fermi/GBM detection: GCN 34584; GECAM-B detection: trigger no. 215; CALET/CGBM detection: trigger no. 1377151581; INTEGRAL/SPI-ACS detection at 2023-08-27 ~06:08:31 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 2023-08-27 06:08:33 UTC. The T90 duration is 21 s (17 s) and the significance during T90 reaches 10.2 sigma (7.3 sigma) for detector unit no. 0 (no. 1). The light curve obtained by VZLUSAT-2 is available here: https://vzlusat2.konkoly.hu/static/share/GRB230827B_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 34593 table
GRB_name GRB230827B
GCN_number 34593
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 34593 SUBJECT: GRB 230827B: CALET Gamma-Ray Burst Monitor detection DATE: 23/08/29 15:56:27 GMT FROM: Yuta Kawakubo at Louisiana State University T. Tamura (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), Y. Shimizu (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 230827B (Fermi GBM Observation: Hamburg et al., GCN Circ. 34584; VZLUSAT-2 detection: Dafcikova et al., GCN Circ. 34585) triggered the CALET Gamma-ray Burst Monitor (CGBM) at 06:08:28.36 UTC on 27 July 2023 (http://cgbm.calet.jp/cgbm_trigger/flight/1377151581/). The burst signal was seen by only the SGM detector. The burst light curve shows a multi-peaked structure that starts at T+2.3 sec, peaks at T+2.7 sec, and ends at T+87.7 sec. The T90 and T50 durations measured by the SGM data are 79.6 +/- 3.7 sec and 57.4 +/- 2.5 sec (40-1000 keV), respectively. The ground-processed light curve is available at http://cgbm.calet.jp/cgbm_trigger/ground/1377151581/ The CALET data used in this analysis are provided by the Waseda CALET Operation Center located at Waseda University.
GCN 34596 table
GRB_name GRB230827B
GCN_number 34596
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 34596 SUBJECT: GRB 230827B: Swift ToO observations DATE: 23/08/29 22:31:52 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Fermi/GBM GRB 230827B. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021620 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 Fermi/GBM 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 34601 table
GRB_name GRB230827B
GCN_number 34601
Detection_method Swift-XRT Other
ra 299.6394°
decl 54.4632°
Circular_text TITLE: GCN CIRCULAR NUMBER: 34601 SUBJECT: GRB 230827B: Swift-XRT afterglow detection DATE: 23/08/30 13:26:29 GMT FROM: Phil Evans at U of Leicester A. Tohuvavohu (U. Toronto), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), B. Sbarufatti (INAF-OAB), D.N. Burrows (PSU), J. D. Gropp (PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Fermi/GBM-detected burst GRB 230827B (GCN Circ. 34584), collecting 3.6 ks of Photon Counting (PC) mode data between T0+231.3 ks and T0+249.7 ks. An uncatalogued X-ray source is detected consistent with being within 9.9 arcsec of the position of ZTF23abaanxz/AT2023qxj (GCN Circ. 34574) and is believed to be the afterglow. Using 3821 s of PC mode data and 4 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 299.63944, +54.46318 which is equivalent to: RA (J2000): 19h 58m 33.47s Dec(J2000): +54d 27' 47.5" with an uncertainty of 2.6 arcsec (radius, 90% confidence). This position is 0.8 arcsec from the ZTF position. The light curve is consistent with a constant source of mean count rate 7.0e-02 ct/sec. A power-law fit gives an index of 2.490 (+0.015, -2.990). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.59 (+0.33, -0.30). The best-fitting absorption column is 4.0 (+2.1, -1.0) x 10^21 cm^-2, consistent with the Galactic value of 3.0 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 5.0 x 10^-11 (6.4 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 4.0 (+2.1, -1.0) x 10^21 cm^-2 Galactic foreground: 3.0 x 10^21 cm^-2 Excess significance: <1.6 sigma Photon index: 1.59 (+0.33, -0.30) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00021620. The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/ToO_GRBs/00021620. This circular is an official product of the Swift-XRT team.
GCN 34604 table
GRB_name GRB230827B
GCN_number 34604
Detection_method CALET
Circular_text TITLE: GCN CIRCULAR NUMBER: 34604 SUBJECT: GRB 230827B: Glowbug gamma-ray detection DATE: 23/08/30 14:51:11 GMT FROM: matthew.kerr@gmail.com M. Kerr, C.C. Cheung, J. E. Grove, R. Woolf (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge (MSFC), and M.S. Briggs (UAH) report: The Glowbug [1,2] gamma-ray telescope, operating on the International Space Station, reports the detection of GRB 230827B, which was also detected by Fermi/GBM, VZLUSAT-2, GECAM-B (trigger 215), INTEGRAL/SPI-ACS, and CALET (GCN 34584, 34585, 34593). Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2023-08-27 06:08:30.320 with a duration of 10.6 s and a total significance of about 57.8 sigma. The light-curve comprises two similar FRED pulses with widths of about 1s, separated by about 5s, each with tails of faint emission lasting about 5s. 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 272 keV. The modeled 10-10000 keV fluence is 1.3e-05 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.