TITLE:   GCN CIRCULAR
NUMBER:  35954
SUBJECT: X-ray transient EP240315a: 3.6 m TNG NIR detection
DATE:    24/03/18 15:24:39 GMT
FROM:    Youdong HU at INAF-OAB <huyoudong072@hotmail.com>

Y.-D. Hu, P. D'Avanzo, M. Ferro, R. Brivio, S. Covino, D. Fugazza, S. Campana (INAF-OAB), A. Rossi (INAF-OAS), D. B. Malesani (DAWN/NBI & Radboud Univ.), A. Melandri (INAF-OAR), L. Di Fabrizio, C. Padilla (INAF-TNG)  on behalf of the CIBO collaboration report:

We observed the field of the fast X-ray transient EP240315a detected by the Einstein Probe mission (Zhang et al., GCNC 35931; Chen et al. GCNC 35951) with the Italian 3.6m TNG telescope equipped with the near-infrared camera NICS to follow up its optical counterpart AT2024eju (TNS Astronomical Transient Report No. 205383). A series of images were obtained with the H filter starting on 2024-03-17 19:58:11 UT (i.e. 2.02 days post T0). The optical counterpart (Srivastav et al., GCN 35932, 35933; Jiang et al., GCN 35935; Saccardi et al., GCN 35936; Rau GCN 35937; Chen GCN 35938; Lipunov, GCN 35940; Leonini et al., GCN 35944; Pankov et al., GCN 35945, Pankov et al. GCNC 35952) is clearly detected in the co-added image with a preliminary result of H(Vega)~19.8 mag (calibrated against the 2MASS catalogue).