TITLE: GCN CIRCULAR NUMBER: 39469 SUBJECT: EP250215A: J band upper limit by SYSU 80cm telescope DATE: 25/02/25 07:01:01 GMT FROM: yanghn8@mail2.sysu.edu.cn
Hao-Nan Yang, Jia-Qi Lin, Si-Yuan Zhu, Zhong-Nan Dong, Wei-Sen Huang, Pu Lin, Jin-Ji Li, Yan Yu, Hao-Ran Zhang, Chun Chen, P H Thomas Tam, Rong-Feng Shen, Bin Ma (Sun Yat-sen University) report on behalf of the SYSU 80cm telescope team:
We observed the field of EP250215A (Fermi GCN 39327; EP GCN 39329) using the Sun Yat-sen University 80cm infrared telescope with 180 x 20 s exposures in J band. The calculated position is RA. = 156.3301 deg, DEC =-27.6997 deg J2000, from EP/FXT observation. Our observations began at 2025-2-15 17:52:00 UTC, 11.39 hours after the EP trigger.
We do not detect any counterpart at the position of the optical afterglow(Liu et al. GCN 39330; Xie et al., GCN 39333; Malesani et al., GCN 39339; and Malesani et al. GCN 39341; R. Sanchez-Ramirez et al. GCN 39343; Jean-Grégoire Ducoin (CPPM) et al. GCN 39344; I. Pérez-Fournon et al. GCN 39348; R.Ruffini et al. GCN 39366; D.Svinkin et al. GCN 39375), down to a 5-sigma depth of J~17.5 Vega magnitudes.
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