GRB240727B

This page lists all entries on GRB240727B in GRBweb

Summary Fermi GBM IPN GCN 36945 GCN 36946 GCN 36949 GCN 36970

Summary table
Variable Value Source
GRB_name_Fermi GRB240727250
T0 6:00:08.960 UTC GCN_circulars,Fermi GBM Det
ra 97.7792° IPN
decl -37.1833° IPN
pos_error 6.67e-02° IPN
T90 18.688 s Fermi_GBM
T90_error 1.056 s Fermi_GBM
T90_start 6:00:09.217 UTC Fermi_GBM
fluence 2.85e-06 erg/cm² Fermi_GBM
fluence_error 7.02e-08 erg/cm² Fermi_GBM
T100 18.945 s
GBM_located False
mjd 60518.25010370371 GCN_circulars,Fermi GBM Det
Fermi GBM table
GRB_name_Fermi GRB240727250
trigger_name bn240727250
ra 97.7858°
decl -37.1800°
datum 2024-07-27
t_trigger 6:00:08.961 UTC
T90 18.688 s
T90_error 1.056 s
T90_start 6:00:09.217 UTC
fluence 2.85e-06 erg/cm²
fluence_error 7.02e-08 erg/cm²
flux_1024 3.42e+00 erg/cm²/s
flux_1024_error 3.52e-01 erg/cm²/s
flux_1024_time 8.70e+00 erg/cm²/s
flux_64 8.42e+00 erg/cm²/s
flux_64_error 2.32e+00 erg/cm²/s
IPN table
GRB_name GRB240727B
ra 97.7792°
decl -37.1833°
pos_error 6.67e-02°
GCN 36945 table
GRB_name GRB240727B
GCN_number 36945
Detection_method Swift Other
ra 97.7860°
decl -37.1800°
Circular_text TITLE: GCN CIRCULAR NUMBER: 36945 SUBJECT: GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst DATE: 24/07/27 12:33:16 GMT FROM: Samuele Ronchini at PSU Samuele Ronchini (PSU), James DeLaunay (PSU), Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 240727B onboard (T0: 2024-07-27T06:00:08.96 UTC, AstroSat GCN 36943, Fermi trig. 743752813). 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), detects the burst in a 16.384 s analysis time bin starting at T0 s with a sqrt(TS) of 45.6. An arcminute localization is found with DeltaLLHOut of 29.3 and a DeltaLLHPeak of 49.37. See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretations of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut. The BAT position is RA, Dec = 97.786, -37.18 deg which is RA(J2000) = 06h 31m 08.64s Dec(J2000) = -37d 10′ 48.0″ with an estimated uncertainty of 4 arcmin radius. XRT and UVOT follow-up has been requested. Results of follow-up observations will be reported in future circulars. 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/
GCN 36946 table
GRB_name GRB240727B
GCN_number 36946
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 36946 SUBJECT: GRB 240727B: Swift ToO observations DATE: 24/07/27 15:19:02 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 240727B. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021701 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 36949 table
GRB_name GRB240727B
GCN_number 36949
Detection_method Fermi GBM Det
t_trigger 6:00:08.960 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 36949 SUBJECT: GRB 240727B: Fermi GBM Observation DATE: 24/07/27 19:00:39 GMT FROM: Cori Fletcher at USRA C. Fletcher (USRA), R. Hamburg (CNRS/IJCLab) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 06:00:08.96 UT on 27 July 2024, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 240727B (trigger 743752813/240727250). which was also detected by Swift/BAT-GUANO (Ronchini et al. 2024, GCN 36945) and AstroSat (Waratkar et al. 2024, GCN 36943). The Fermi GBM on-ground location is consistent with the Swift/BAT-GUANO position. The angle from the Fermi LAT boresight is 114 degrees. The GBM light curve consists of multiple peaks with a duration (T90) of about 19 s (50-300 keV). The time-averaged spectrum from T0-3.3 to T0+20.2 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.3 +/- 0.1 and the cutoff energy, parameterized as Epeak, is 850 +/- 90 keV. The event fluence (10-1000 keV) in this time interval is (1.52 +/- 0.05)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+8.7 s in the 10-1000 keV band is 3.4 +/- 0.4 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 848 +/- 116 keV, alpha = -0.3 +/- 0.1 and beta = -2.5 +/- 0.3. 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 36970 table
GRB_name GRB240727B
GCN_number 36970
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 36970 SUBJECT: GRB 240727B: Swift-XRT observations DATE: 24/07/29 08:50:31 GMT FROM: Phil Evans at U of Leicester D.N. Burrows (PSU), J. D. Gropp (PSU), S. Dichiara (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), B. Sbarufatti (INAF-OAB), C. Salvaggio (INAF-OAB), M. Ferro (INAF-OAB) 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, Swift/BAT-GUANO and Astrosat/CZTI detected burst GRB 240727B (Fletcher et al. 2024, GCN 36949; Ronchini et al. 2024, GCN 36945; Waratkar et al. 2024, GCN 36943), collecting 4.9 ks of Photon Counting (PC) mode data between T0+33.5 ks and T0+52.2 ks. No X-ray sources have been detected within 296 arcsec of the Swift/BAT-GUANO position. The 3-sigma upper limit in the field is 0.003 ct s^-1, corresponding to a 0.3-10 keV observed flux of 1.0e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). Three uncatalogued sources were detected too far from the GRB position to be likely afterglow candidates. The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021701. This circular is an official product of the Swift-XRT team.