{
  "eventId": "GRB 260127A",
  "bibcode": "2026GCN.43543....1M",
  "submittedHow": "web",
  "body": "D. B. Malesani (DAWN/NBI and Radboud), J. An (NAOC), L. B He (NAOC), G. Corcoran (UCD), K. Valeckas (NOT & NBI), L. Izzo (INAF/OAC and DARK/NBI), A. Martin-Carrillo (UCD), A. Saccardi (CEA/Irfu), B. Schneider (LAM) report on behalf of a larger collaboration:\n\nWe observed the optical counterpart (Saccardi & Malesani, GCN 43530; Wu et al., GCN 43537; Hagio et al., GCN 43540) of GRB 260127A (Klingler et al., GCN 43529; Fermi GBM team, GCN 43528) using the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations were carried out in the SDSS i, z, and r filters (with exposure times 3x300, 5x200, and 3x300 s, respectively).\n\nThe optical counterpart is detected in the stacked images for all bands. We report the following magnitudes:\n\n| Filter | Epoch (UT) | Time since GRB (hr) | Exp time (s) | Magnitude (AB) |\n| ------ | ---------- | ------------------- | ------------ | -------------- |\n| i      | Jan 28.197 | 10.88               | 3x300        | 22.30 +- 0.08  |\n| z      | Jan 28.209 | 11.18               | 5x200        | 22.05 +- 0.18  |\n| r      | Jan 28.243 | 12.00               | 3x300    \t   | 22.30 +- 0.06  |\n\n\nThe above magnitudes are calibrated against the Pan-STARRS catalog and are not corrected for Galactic extinction. We note that at the coordinates of the optical counterpart a faint source is reported in the Legacy Survey catalogue. Considering its tabulated magnitudes (r = 23.3, i = 23.2, z = 22.3), the transient emission is thus significantly contaminated by the host flux.\n",
  "createdOn": 1769619198481,
  "subject": "GRB 260127A: NOT optical observations",
  "circularId": 43543,
  "format": "text/plain",
  "submitter": "Daniele Bjørn Malesani at Cosmic Dawn Center, Niels Bohr Institute <daniele.malesani@nbi.ku.dk>"
}