GRB250121A

This page lists all entries on GRB250121A in GRBweb

Summary Fermi GBM IPN GCN 39006 GCN 39011 GCN 39018 GCN 39023

Summary table
Variable Value Source
GRB_name_Fermi GRB250121983
T0 23:36:05 UTC GCN_circulars,Fermi GBM final loc
ra 225.1417° IPN
decl -34.3667° IPN
pos_error 2.33e-01° IPN
T90 5.248 s Fermi_GBM
T90_error 0.453 s Fermi_GBM
T90_start 23:36:05.907 UTC Fermi_GBM
fluence 5.69e-06 erg/cm² Fermi_GBM
fluence_error 2.50e-08 erg/cm² Fermi_GBM
T100 6.155 s
GBM_located False
mjd 60696.98339120371 GCN_circulars,Fermi GBM final loc
Fermi GBM table
GRB_name_Fermi GRB250121983
trigger_name bn250121983
ra 225.1500°
decl -36.9000°
pos_error 2.61e+00°
datum 2025-01-21
t_trigger 23:36:05.779 UTC
T90 5.248 s
T90_error 0.453 s
T90_start 23:36:05.907 UTC
fluence 5.69e-06 erg/cm²
fluence_error 2.50e-08 erg/cm²
flux_1024 1.41e+01 erg/cm²/s
flux_1024_error 4.70e-01 erg/cm²/s
flux_1024_time 3.20e-01 erg/cm²/s
flux_64 1.76e+01 erg/cm²/s
flux_64_error 1.44e+00 erg/cm²/s
IPN table
GRB_name GRB250121A
ra 225.1417°
decl -34.3667°
pos_error 2.33e-01°
GCN 39006 table
GRB_name GRB250121A
GCN_number 39006
Detection_method Fermi GBM final loc
t_trigger 23:36:05 UTC
ra 225.1000°
decl -36.9000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 39006 SUBJECT: GRB 250121A: Fermi GBM Final Real-time Localization DATE: 25/01/21 23:46:35 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 23:36:05 UT on 21 Jan 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250121A (trigger 759195370.779232 / 250121983). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 225.1, Dec = -36.9 (J2000 degrees, equivalent to J2000 15h 00m, -36d 53'), with a statistical uncertainty of 1.1 degrees. The angle from the Fermi LAT boresight is 16.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250121983/quicklook/glg_skymap_all_bn250121983.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250121983/quicklook/glg_healpix_all_bn250121983.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250121983/quicklook/glg_lc_medres34_bn250121983.gif
GCN 39011 table
GRB_name GRB250121A
GCN_number 39011
Detection_method INTEGRAL
Circular_text TITLE: GCN CIRCULAR NUMBER: 39011 SUBJECT: GRB 250121A: INTEGRAL/SPI-ACS detection DATE: 25/01/22 11:04:29 GMT FROM: Aishwarya L Thakur at INAF-IAPS, Rome Patrizia Barria(a,b), Giulia Gianfagna(a), James Craig Rodi(a), Aishwarya Linesh Thakur(a), Lorenzo Natalucci(a,b), Luigi Piro(a) report: GRB 250121A was discovered by Fermi/GBM (GCN 39006, Fermi/LAT GCN 39010) on 2025-01-21T23:36:05 (UTC). We searched for a corresponding counterpart in the INTEGRAL/SPI-ACS data. In an SPI-ACS light curve above 80 keV, we find a signal temporally coincident with the GBM detection, having an approximate duration of ~ 4 sec. The signal consists of a single pulse over this duration. The approximate peak count rate in SPI-ACS is 74,000 cts/s for E>80 keV, over a median background rate of 62,800 cts/s. This work is based on observations with INTEGRAL, an ESA project with instruments and a science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Switzerland, and Spain), and with the participation of Russia and the USA. The SPI-ACS detector system has been provided by MPE Garching/Germany. ----- (a) INAF/IAPS-Rome (b) ICSC National Research Centre for High-Performance Computing
GCN 39018 table
GRB_name GRB250121A
GCN_number 39018
Detection_method Fermi GBM Det
t_trigger 23:36:05.780 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 39018 SUBJECT: GRB 250121A: Fermi GBM Observation DATE: 25/01/23 20:33:41 GMT FROM: Matt Godwin Matt Godwin (UAH) and C.Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 23:36:05.78 UT on 21 January 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250121A (trigger 759195370/250121983). which was also detected by Fermi-LAT (Holzmann Airasca et al. 2025, GCN 39010). The Fermi GBM on-ground location is consistent with the Fermi-LAT position. (Fermi GBM Team et al. 2025, GCN 39006) The angle from the Fermi LAT boresight is 15 degrees. This burst was also independently detected by INTEGRAL SPI-ACS. The GBM light curve consists of one peak with a duration (T90) of about 5.2 s (50-300 keV). The time-averaged spectrum from T0-0.4 to T0+5.8 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -0.65 +/- 0.05 and the cutoff energy, parameterized as Epeak, is 230 +/- 10 keV. The event fluence (10-1000 keV) in this time interval is (5.8 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+0.32 s in the 10-1000 keV band is 14.0 +/- 0.3 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak= 210 +/- 20 keV, alpha = -0.59 +/- 0.07 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 39023 table
GRB_name GRB250121A
GCN_number 39023
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 39023 SUBJECT: GRB 250121A: Swift/BAT-GUANO localization skymap of a burst DATE: 25/01/24 17:29:42 GMT FROM: Samuele Ronchini at PSU Samuele Ronchini (PSU), James DeLaunay (PSU), Aaron Tohuvavohu (Caltech), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: Swift/BAT did not localize GRB 250121A onboard (T0: 2025-01-21T23:36:05.78 UTC, Fermi GBM GCN 39006 and 39018, Fermi LAT GCN 39010, INTEGRAL GCN 39011, CALET GCN 39021) 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 38.1 in a 2.048 s analysis time bin, starting at T0 - 0.0001 s. Using the NITRATES analysis, parameter estimation was performed to obtain the localization of this burst in the form of a HEALPIX Multi-Order Coverage (MOC) skymap. This localization accounts for both statistical and systematic errors. More details in the creation and calibration of these maps will soon be published (DeLaunay et al. 2025. in prep) The 90% credible area is 153 deg2 and the 50% credible area is 46 deg2. The integrated probability inside the coded field of view is <1%. The NITRATES skymap is consistent with the Fermi-GBM and Fermi-LAT localizations. The joint NITRATES+GBM localization has a 90% credible area of 68 deg2 and a 50% credible area of 17 deg2 A plot of the probability skymap can be viewed here: [skymap_plot](https://guano.swift.psu.edu/trigger_report?id=759195400/#:~:text=Probability%20Skymap) The probability skymap file can be downloaded from the link here [skymap_fits_file](https://guano.swift.psu.edu/files/759195400/0_n_PROBMAP) Instructions on how to read and manipulate this map can be found here: https://guano.swift.psu.edu/documentation More details about this burst can be found on the trigger report page here: https://guano.swift.psu.edu/trigger_report?id=759195400 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/