{
  "submitter": "ankur ghosh at CAPP, University of Johannesburg <ghosh.ankur1994@gmail.com>",
  "submittedHow": "web",
  "subject": "EP 250108A: Late-time optical observation by LCO",
  "editedOn": 1769437371989,
  "format": "text/plain",
  "eventId": "EP250108a",
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of Malte Busmann at Ludwig-Maximilians-Universität München <m.busmann@physik.lmu.de>",
  "createdOn": 1737353544998,
  "bibcode": "2025GCN.38995....1G",
  "body": "Ankur Ghosh, Soebur Razzaque (CAPP, University of Johannesburg), Rahul Gupta (NASA GSFC),  Alexander Moskvitin, Yulia Sotnikova (SAO RAS), Naveen Dukiya (ARIES) on behalf of a larger collaboration. \n\nWe observed the field of the EP 250108A triggered by Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP)  (Li et al., GCN 38861) in V filter of  the 1-meter Sinistro telescope at the Las Cumbres Observatory Global Telescope (LCOGT) node located at South African Astronomical Observatory (SAAO). The 1-m Sinistro telescope is equipped with a 4K x 4K CCD (FOV: 26 x 26 arcmin, scale: 0.39 arcsec/pixel).\nObservations began on January 19, 2025, starting 11.4 days after the GRB trigger.\n\nWe clearly detect the optical transient (OT) reported by GCNs ( Zhu et al., GCN 38885; Malesani et al., GCN 38902; Kumar et al., GCN 38907; Zhu et al, GCN 38908; Levan et al., GCN 38909; Izzo, GCN 38912; Zou et al., GCN 38914; Moskvitin & Spiridonova, GCN 38925; Song et al., GCN 38972, Eyles-Ferris et al., GCN 38983)  in our V, r band image. There is a confirmation of the Ic-BL supernova connection with EP 250108A (Xu et al., GCN 38984, Levan et al., GCN 38987). Observations are still ongoing in other filters.\n\n|Date|\t\t|UTstart|\t|t-T0 (days)|\t|Exp (sec)|\t|Filter|\t|Magnitude|       \n2025-01-19\t 21:59:26.59\t11.4\t\t1 x 1200 \tV\t\tV = 20.37 +/- 0.04\n\nThe field was calibrated against nearby APASS stars, with magnitudes converted using Lupton (2005) equations, and has not been corrected for Galactic extinction.\n",
  "circularId": 38995,
  "version": 2
}