GCN Circular 39851
Subject
EP250304a: VLT/MUSE spectroscopic observation of its associated supernova SN 2025fhm
Date
2025-03-23T09:41:34Z (3 days ago)
From
Antonio Martin-Carrillo at UCD,Space Science Group <antonio.martin-carrillo@ucd.ie>
Via
Web form
L. Izzo (INAF-OACN and DARK/NBI), A. Martin-Carrillo (UCD), D. B. Malesani (Radboud and DAWN/NBI), A. J. Levan (Radboud and Warwick), P. G.Jonker (Radboud Univ.), L. Cotter (UCD), J. van Dalen (Radboud Univ.), G. Corcoran (UCD), K. Wiersema (Herts), F. E. Bauer (PUC), report on behalf of a larger collaboration:
We observed the optical counterpart (Liu et al., GCN 39583; Page et al., GCN 39584; Saccardi et al., GCN 39585; Shilling et al., GCN 39587; Gupta et al., GCN 39593; Ghosh et al., GCN 39594) of the fast X-ray transient EP250304a (Chen et al., GCN 39580) using the ESO VLT UT4 (Yepun) equipped with the MUSE spectrograph on 2025-03-22 at 02:45:04 UT (about 18.05 days after trigger, 15 days in the rest frame). A series of 4x470 s exposures were taken for this observation.
From a preliminary reduction, the continuum is well detected over the wavelength range of 5000 to 9000 AA. Broad features, typical of broad-lined supernovae expanding at relativistic speeds, can be clearly identified, with SNID finding a good match with SN1998bw at 14 days after the explosion.
Further observations are planned.
We acknowledge the excellent support from the ESO staff in Paranal, in particular Thallis Pessi and Francisco Caceres.