EP250908a
GCN Circular 41757
Subject
The EP-WXT trigger EP250908a/01709240652 is not a real source
Date
2025-09-09T03:14:28Z (22 days ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
C. Zhou (HUST), Y. H. Cheng (SWIFAR, YNU), S. L. Wang (YNU), T. Y. Liu, H. Q. Cheng, C. C. Jin (NAO, CAS) report on behalf of the Einstein Probe (EP) team
The EP-WXT trigger EP250908a/01709240652 at the time of 2025-09-08T15:43:42 is not a real source based on ground data analysis.
GCN Circular 41751
Subject
EP#01709240652 (possibly EP250908a): FTW optical and NIR observations
Date
2025-09-08T23:54:00Z (22 days ago)
From
Malte Busmann at Ludwig-Maximilians-Universität München <m.busmann@physik.lmu.de>
Via
Web form
Malte Busmann (LMU), Xander Hall (Carnegie Mellon U.), Brendan O’Connor (Carnegie Mellon U.), Daniel Gruen (LMU), and Antonella Palmese (Carnegie Mellon U.) report:
We observed the 90% localization of EP/WXT trigger 01709240652 (possibly EP250908a) for 10 x 180 s in the r, i, and J-band simultaneously with the Three Channel Imager (3KK) at the Fraunhofer Telescope at Wendelstein Observatory (FTW). Our observations started at 2025-09-08T21:33:56 (0.23 days after trigger). We performed difference imaging with i-band templates from PS1 and J-band templates from UKIDSS. We do not detect any new sources in the difference images. The mean 3-sigma depth of our J band difference is J > 20.4 AB mag, calibrated against the 2MASS catalog and not corrected for Galactic extinction.
We thank Michael Schmidt from the Wendelstein Observatory for obtaining these observations.