TITLE: GCN CIRCULAR NUMBER: 37008 SUBJECT: EP240801a: NOT optical observations DATE: 24/08/02 00:33:18 GMT FROM: Daniele B. Malesani at IMAPP / Radboud University <d.malesani@astro.ru.nl> D. B. Malesani (DAWN/NBI and Radboud Univ.), J. Quirola-Vásquez (Radboud Univ.), J. van Dalen (Radboud Univ.), P. G. Jonker (Radboud Univ), A. J. Levan (Radboud Univ. & Warwick Univ.), F. E. Bauer (PUC), M. E. Ravasio (Radboud Univ.), D. Mata Sanchez (IAC), M. A. P. Torres (IAC), on behalf of a larger collaboration, D. Xu (NAOC), Z. P. Zhu (NAOC): We report on optical follow-up observations of the Einstein Probe fast X-ray transient EP240801a (Zhou et al., GCN 36997). We observed the optical counterpart of EP240801a (Fu et al., GCN 36998) using the ALFOSC instrument mounted on the Nordic Optical Telescope (NOT), with an exposure of 3x300 s in the SDSS-r band. Observations started on 2024-08-01T22:37:41 UT, that is ~13.56 hours after the EP trigger, at an airmass of ~2. An object is detected at a position consistent with the one reported by Fu et al. (GCN 36998), for which we measure a preliminary magnitude r = 21.67 +- 0.04 mag, calibrated against nearby Pan-STARRS sources. We thank the Nordic Optical Telescope team, in particular Alba Casasbuenas Corral, for making these observations possible. View this GCN Circular online at https://gcn.nasa.gov/circulars/37008. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...