GRB 250223C
GCN Circular 39459
Subject
GRB 250223C: Fermi GBM Final Real-time Localization
Date
2025-02-24T17:27:23Z (3 months 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 16:18:20 UT on 23 Feb 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250223C (trigger 762020305.175056 / 250223679).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 262.6, Dec = 41.0 (J2000 degrees, equivalent to J2000 17h 30m, 41d 00'), with a statistical uncertainty of 5.1 degrees.
The angle from the Fermi LAT boresight is 41.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250223679/quicklook/glg_skymap_all_bn250223679.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/bn250223679/quicklook/glg_healpix_all_bn250223679.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250223679/quicklook/glg_lc_medres34_bn250223679.gif
GCN Circular 39470
Subject
GRB 250223C: SVOM/GRM observation of a long burst
Date
2025-02-25T13:44:49Z (3 months ago)
From
yqzhang_cl@163.com
Via
Web form
SVOM/GRM team: Yan-Qiu Zhang, Chao Zheng, Chen-Wei Wang, Shi-Jie Zheng, Wen-Jun Tan, Chen-Wei Wang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP)
SVOM/ECLAIRs team: Nicolas Dagoneau (CEA), Maria-Grazia Bernardini (INAF-OAB), Jean-Luc Atteia (IRAP)
report on behalf of the SVOM team:
SVOM/GRM was triggered on-ground by a long burst GRB 250223C at 2025-02-23T16:18:36.500 UTC (T0), which was also observed by Fermi/GBM (Fermi GBM team, GCN #39459).
With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multi-pulses with a T90 of 40.50 +/- 15.03 s in the 15-2000 keV band.
ECLAIRs was not collecting data at the time of this burst.
The SVOM/GRM light curve can be found here:
https://www.bursthub.cn//admin/static/svgrb250223C.png
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/GRM point of contact for this burst is: Yan-Qiu Zhang (IHEP) (zhangyanqiu@ihep.ac.cn)