GCN Circular 43900

Subject
GRB 260228A: EP-FXT follow-up observation
Event
GRB 260228A
Date
2026-03-03T07:00:27Z (8 days ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
Y.H.Cheng, D.Zhu, K.J.Zhang (SWIFAR, YNU), H.C.Ding, T.Wu (AHNU), C.C.Jin (NAOC) on behalf of the Einstein Probe (EP) team:

EP-FXT performed a follow-up observation of the SVOM/ECLAIRs-detected burst GRB 260228A (SVOM/sb26022802; Julakanti et al., GCN 43882Loading...
 
 ) starting at 2026-02-28T22:50:15 UTC, approximately 5 minutes after the SVOM trigger, with a total exposure time of 5527 s. Six uncataloged sources are detected within the ECLAIRs error circle. Preliminary analysis on these sources is automatically conducted, and the details are listed as follows. 

EPF_J155124.0+262035
RA (J2000): 237.8501
Dec (J2000): 26.3431
Flux: 2.1373 x 10^-12 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 1.6673 x 10^-13 erg/s/cm2 (1 sigma)

EPF_J155105.1+261820
RA (J2000): 237.7711
Dec (J2000): 26.3055
Flux: 9.6351 x 10^-14 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 1.891 x 10^-14 erg/s/cm2 (1 sigma)

EPF_J155123.9+261238
RA (J2000): 237.8498
Dec (J2000): 26.2105
Flux: 7.077 x 10^-14 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 1.6973 x 10^-14 erg/s/cm2 (1 sigma)

EPF_J155130.8+261248
RA (J2000): 237.8781
Dec (J2000): 26.2134
Flux: 1.231 x 10^-13 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 2.1478 x 10^-14 erg/s/cm2 (1 sigma)


EPF_J155140.7+261349
RA (J2000): 237.9195
Dec (J2000): 26.2303
Flux: 1.5723 x 10^-13 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 3.1532 x 10^-14 erg/s/cm2 (1 sigma)

EPF_J155148.8+262150
RA (J2000): 237.9533
Dec (J2000): 26.3640
Flux: 1.0194 x 10^-13 erg/s/cm2 (observed, 0.5-10 keV)
Flux_err: 2.9166 x 10^-14 erg/s/cm2 (1 sigma)


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).