GRB 250624A
GCN Circular 40817
Subject
GRB 250624A: Fermi GBM Final Real-time Localization
Date
2025-06-24T19:46:55Z (a day ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 19:36:21 UT on 24 Jun 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250624A (trigger 772486586.849764 / 250624817).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 10.6, Dec = 16.6 (J2000 degrees, equivalent to J2000 00h 42m, 16d 36'), with a statistical uncertainty of 5.3 degrees.
The angle from the Fermi LAT boresight is 56.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250624817/quicklook/glg_skymap_all_bn250624817.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/bn250624817/quicklook/glg_healpix_all_bn250624817.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250624817/quicklook/glg_lc_medres34_bn250624817.gif
GCN Circular 40818
Subject
Fermi GRB 250624A: Global MASTER-Net observations report
Date
2025-06-24T20:30:25Z (a day 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-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 250624A ( Fermi GBM team, GCN 40817) errorbox 542 sec after notice time and 573 sec after trigger time at 2025-06-24 19:45:55 UT, with upper limit up to 14.4 mag. Observations started at twilight. The observations began at zenith distance = 57 deg. The sun altitude is -8.0 deg.
The galactic latitude b = -46 deg., longitude l = 121 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2915767
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
574 | 2025-06-24 19:45:55 | MASTER-Tunka | (00h 36m 20.26s , +16d 05m 54.9s) | C | 1 | 14.4 |
584 | 2025-06-24 19:46:05 | MASTER-Tunka | (00h 36m 20.23s , +16d 05m 54.7s) | C | 1 | 14.4 |
590 | 2025-06-24 19:46:10 | MASTER-Tunka | (00h 36m 20.23s , +16d 05m 54.6s) | C | 1 | 14.4 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.