GRB 250607A
GCN Circular 40648
Subject
GRB 250607A: Fermi GBM Final Localization
Date
2025-06-07T15:22:38Z (20 days ago)
From
rhamburg@usra.edu
Via
Web form
The Fermi GBM team reports the detection of a likely LONG GRB.
"At 14:00:55.64 UT on 07 June 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 250607A (trigger 770997660/250607584).
The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 243.84, Dec = -24.71 (J2000 degrees, equivalent to J2000 16h 15m, -24d 42'),
with a statistical uncertainty of 10.15 degrees.
The angle from the Fermi LAT boresight is 90 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250607584/quicklook/glg_skymap_all_bn250607584.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/bn250607584/quicklook/glg_healpix_all_bn250607584.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250607584/quicklook/glg_lc_medres34_bn250607584.gif"
GCN Circular 40651
Subject
GRB 250607A: SVOM/GRM observation of a long burst
Date
2025-06-09T03:13:00Z (19 days ago)
From
wenlongzhang2018@163.com
Via
Web form
SVOM/GRM team: Wen-Long Zhang, Wen-Jun Tan, Chen-Wei Wang, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP)
SVOM/ECLAIRs team: Jean-Luc Atteia (IRAP)
report on behalf of the SVOM team:
SVOM/GRM was triggered in-flight by a long burst GRB 250607A (SVOM trigger reference: sb25060704) at 2025-06-07T14:00:56.000 UTC (T0), which is also detected by Fermi/GBM ( Fermi GBM team., GCN #40648).
With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of a single pulse with a T90 of 12.60 +7.20/-5.40 s in the 15-5000 keV band.
The SVOM/GRM light curve can be found here:
https://www.bursthub.cn//admin/static/svgrb250607A.png
In addition, the position of this burst, as determined by Fermi/GBM (RA = 243.84, Dec = -24.71 , GCN #40648), is located at about 53 degrees from the SVOM optical axis, and outside the ECLAIRs field of view.
With this localization, the time-averaged spectrum from T0-5s to T0+5s is best fitted by a power law function. The power law index is -1.82+/-0.08. The event fluence (10-1000 keV) in this time interval is (1.37 +0.15/-0.15)E-06 erg/cm^2.
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS.
The SVOM point of contact for this burst is: Wen-Long Zhang (IHEP)(zhangwl@ihep.ac.cn)