TITLE:   GCN CIRCULAR
NUMBER:  37809
SUBJECT: GRB 241001A: EP-FXT afterglow detection
DATE:    24/10/18 07:00:20 GMT
FROM:    Damien Turpin at CEA-Saclay <dturpin-astro@hotmail.com>

D. Turpin (CEA), M. Xuan, J. W. Hu, H. W. Pan, W. Yuan (NAOC, CAS), C. Plasse, D. Adrien (CEA/irfu), J. Guan, C. K. Li, Y . Chen, S. M. Jia, W. W. Cui, D. W. Han, W. Li, C. Z. Liu, F . J. Lu, L. M. Song, J. Wang, J. J. Xu, J. Zhang, S. N. Zhang, H. S. Zhao, X. F . Zhao (IHEP , CAS), Y . Liu, C. C. Jin, C. Zhang, Z. X. Ling, J. Wang, L. P . Xin (NAOC,CAS), E. Kuulkers, A. Santovincenzo (ESA), P . O'Brien (Univ. of Leicester), K. Nandra, A. Rau (MPE), B. Cordier (CEA) on behalf of the SVOM and Einstein Probe teams

We performed a follow-up observation of GRB 241001A (Dagoneau et al., GCN 37655)  with the Follow-up X-ray Telescope (FXT) on board the Einstein Probe (EP) mission. The observation started at 2024-10-02T05:36:36.895 (T-TGRB ~ 0.52 day) for about 6 ks of exposure in total. 

We detected an uncatalogued x-ray source at a position consistent with the Swift/XRT afterglow (Osborne et al., GCN 37725). Compared to the first Swift/XRT epoch (Osborne et al., GCN 37670) the source had faded by about an order of magnitude to F_X =  5.1e-14 +/- 1.2e-14 erg.cm-2.s-1 in the 0.3-10 keV energy band.
 
We thus confirm that the Swift/XRT source #2 is the afterglow of GRB 241001A.
 
The above observation was made with the EP-FXT instrument. 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). EP is a mission of the Chinese Academy of Sciences in collaboration with ESA, MPE and CNES.