GRB 250510B
GCN Circular 40418
Subject
GRB 250510B: Fermi GBM Final Localization
Date
2025-05-10T09:49:01Z (19 days ago)
From
A. Holzmann Airasca at University of Trento and INFN Bari <a.holzmannairasca@unitn.it>
Via
Web form
The Fermi GBM team reports the detection of a likely LONG GRB
"At 06:41:54.06 UT on 10 May 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250510B (trigger 768552119/250510279).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 128.93, Dec = -24.76 (J2000 degrees, equivalent to J2000 08h 35m, -24d 45'),
with a statistical uncertainty of 2.39 degrees.
The angle from the Fermi LAT boresight is 103 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250510279/quicklook/glg_skymap_all_bn250510279.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/bn250510279/quicklook/glg_healpix_all_bn250510279.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250510279/quicklook/glg_lc_medres34_bn250510279.gif"
GCN Circular 40419
Subject
GRB 250510B: Swift/BAT-GUANO localization skymap of a burst
Date
2025-05-10T13:48:28Z (19 days ago)
From
Samuele Ronchini at PSU <sjs8171@psu.edu>
Via
Web form
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 250510B onboard (T0: 2025-05-10T06:41:54.06 UTC, Fermi GCN 40418)
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 11.67 in a 8.192 s analysis time bin, starting at T0 - 2.051 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 9,213 deg2 and the 50% credible area is 2,424 deg2.
The integrated probability inside the coded field of view is 4%.
The NITRATES skymap is consistent with the Fermi localization (GCN 40418). The combined Fermi/GBM+NITRATES 90% credible area is 550 deg2 and the 50% credible area is 116 deg2.
A plot of the probability skymap can be viewed here:
[skymap_plot](https://guano.swift.psu.edu/trigger_report?id=768552149/#:~:text=Probability%20Skymap)
The probability skymap and joint skymap files can be downloaded from the links here
[skymap_fits_file](https://guano.swift.psu.edu/files/768552149/0_n_PROBMAP)
[joint_skymap_fits_file](https://guano.swift.psu.edu/files/768552149/0_n_JOINTMAP)
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=768552149
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 Circular 40425
Subject
Fermi GRB 250510B: Global MASTER-Net observations report
Date
2025-05-11T01:31:12Z (19 days ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko,
G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A.Sosnovskij (CrAO),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity),
D.Buckley (SAAO),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)
MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 250510B ( Fermi GBM team, GCN 40418) errorbox 62438 sec after notice time and 62477 sec after trigger time at 2025-05-11 00:03:11 UT, with upper limit up to 19.0 mag. The observations began at zenith distance = 27 deg. The sun altitude is -28.5 deg.
The galactic latitude b = 9 deg., longitude l = 250 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2866812
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
62497 | 2025-05-11 00:03:11 | MASTER-OAFA | (08h 43m 33.97s , -26d 38m 01.3s) | C | 40 | 17.5 |
62508 | 2025-05-11 00:03:11 | MASTER-OAFA | (08h 33m 17.64s , -26d 59m 17.6s) | C | 60 | 18.8 |
62575 | 2025-05-11 00:04:28 | MASTER-OAFA | (08h 51m 56.95s , -24d 43m 41.9s) | C | 40 | 17.6 |
62585 | 2025-05-11 00:04:29 | MASTER-OAFA | (08h 41m 50.32s , -25d 05m 00.8s) | C | 60 | 19.0 |
62653 | 2025-05-11 00:05:47 | MASTER-OAFA | (08h 35m 04.55s , -24d 42m 42.7s) | C | 40 | 17.6 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 40427
Subject
GRB 250510B: Fermi GBM Observation
Date
2025-05-11T05:33:44Z (19 days ago)
From
A. Holzmann Airasca at University of Trento and INFN Bari <a.holzmannairasca@unitn.it>
Via
Web form
A. Holzmann Airasca (UniTrento and INFN Bari) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team:
"At 06:41:54.06 UT on 10 May 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250510B (trigger 768552119/250510279).
which was also detected by Swift/BAT-GUANO (S. Ronchini et al. 2025, GCN 40419).
The Fermi GBM on-ground location is consistent with the Swift/BAT-GUANO position.
The angle from the Fermi LAT boresight is 103 degrees.
The GBM light curve consists of main emission episode with a duration (T90)
of about 35 s (50-300 keV). The time-averaged spectrum
from T0+0.51 to T0+35.58 s is
best fit by a Band function with Epeak = 147 +/- 15 keV,
alpha = 0.71 +/- 0.38, and beta = -2.79 +/- 0.49.
The event fluence (10-1000 keV) in this time interval is
(4.79 +/- 0.32)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+2.01 s in the 10-1000 keV band is 2.44 +/- 0.22 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/"