{
  "circularId": 43009,
  "bibcode": "2025GCN.43009....1M",
  "editedOn": 1765065582470,
  "subject": "GRB 251205A: NOT optical observations",
  "version": 2,
  "createdOn": 1765014300894,
  "body": "D. B. Malesani (DAWN/NBI and Radboud), A. Martin-Carrillo (UCD), Z.P. Zhu (NAOC), A. K. Aris-Kiss (Helsinki), N. Routamo (Helsinki), M. Korp-Lagg (Aalto University), S. Wedemeyer (Oslo), S. Armas Perez (NOT) report on behalf of a larger collaboration:\n\nWe observed the optical afterglow of GRB 251205A (Lanava et al., GCN 43005; Lipunov et al., GCN 43006; de Ugarte Postigo et al., GCN 43008) using the Nordic Optical Telescope (NOT) equipped with the StanCam camera. Observations started on 2025-12-06 at 05:25:33 UT (5.75 hr after the trigger). Five 150 s observations were taken using the StanCam “interference i” filter.\n\nThe optical afterglow is well detected in single images. At a mean time of 5.90 hr after the trigger, we measure a magnitude\n\ni = 17.93 +- 0.03.\n\nThis magnitude is in the AB system and is not corrected for Galactic extinction. We note that, due to the small field-of-view of StanCam, only one star from the Pan-STARRS catalog could be used for photometric calibration. Considering that the StanCam i filter is (slightly) different from the Pan-STARRS one, an extra systematic error of 0.1 mag should be conservatively added to the photometric error budget.",
  "submitter": "Daniele Bjørn Malesani at Cosmic Dawn Center, Niels Bohr Institute <daniele.malesani@nbi.ku.dk>",
  "submittedHow": "web",
  "editedBy": "Vidushi Sharma at NASA GSFC/UMBC <vidushi.sharma@nasa.gov> on behalf of Daniele Bjørn Malesani at Cosmic Dawn Center, Niels Bohr Institute <daniele.malesani@nbi.ku.dk>",
  "eventId": "GRB 251205A",
  "format": "text/plain"
}