TITLE:   GCN CIRCULAR
NUMBER:  38214
SUBJECT: EP241113b/GRB 241113B: EP detection of GRB 241113B
DATE:    24/11/14 09:01:38 GMT
FROM:    EP Team at NAOC/CAS <ep_ta@bao.ac.cn>

Z. Y. Liu, M. Q. Huang (USTC), C. Y. Dai (NJU), X. P. Xu, M. H. Zhang, W. Yuan (NAO, CAS) report on behalf of the Einstein Probe team:

We report on the detection of an X-ray transient, designated EP241113b, by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission. The WXT position of EP241113b is R.A.= 110.233 deg, DEC = 46.800 deg (J2000) with an uncertainty of 2.5 arcmin (radius, 90% C.L. statistical and systematic). 

The lightcurve of the transient observed by the WXT lasts around 100 seconds. The 0.5-4.0 keV spectrum can be fitted using an absorbed power law with a photon index of 1.5 +/- 0.7, and a column density of 2.7 (+/- 1.8) ×10^(21) cm^-2. The derived average flux is estimated to be around 1.5 (+/- 0.4 ) ×10^(-9) erg/s/cm^2 in 0.5-4.0 keV.

EP241113b is spatially and temporally consistent with GRB 241113B (GCN 38196; GCN 38212). The burst started at 2024-11-13T11:22:50 (UTC), which is about 15 seconds before the SVOM/ECLAIRs trigger time (2024-11-13T11:23:05). 

 Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics).