{
  "eventType": [
    "GRB",
    "Optical Transient"
  ],
  "submittedHow": "web",
  "format": "text/markdown",
  "subject": "GRB 261029A / AT2026ahaw: r- and i-band optical follow-up with the PKU 60cm Telescope",
  "eventId": "GRB 261029A",
  "submitter": "Y.C. Kang at Peking University <yckang@stu.pku.edu.cn>",
  "createdOn": 1793280774019,
  "body": "Yacheng Kang (PKU), Xinmiao Zhao (PKU), and Fangzhou Ren (PKU) report on behalf of the PKU HiTF (High-energy Transients Follow-up) group:\n\nWe observed the field of GRB 261029A, triggered by Fermi/GBM (Fermi GBM team, GCN 46071; T0 = 2026-10-29T01:27:03) and SVOM/ECLAIRs (Goto et al., GCN 46072), using the PKU 60cm telescope at Xinglong Observatory, NAOC. Observations were conducted in the r and i bands at approximately 10 hr after the Fermi/GBM trigger.\n\nIn the stacked r- and i-band images, we clearly detect the optical counterpart in the difference images at a position consistent with previous GCN reports (O'Neill et al., GCN 46073; He et al., GCN 46078; Wang et al. GCN 46079; De et al., GCN 46080; Cotter et al., GCN 46081; Álvarez et al., GCN 46083; Yin et al., GCN 46084; Shi et al., GCN 46088). Preliminary photometry is calibrated against nearby Pan-STARRS field stars and reported in the AB magnitude system, without correction for Galactic extinction.\n\nThe observation log is summarized below following the time sequence:\n\n|    Date    |  Start_UT   | T_mid - T0 (days) | Filter | Exposure (s) | Magnitude (AB) |\n| :--------: | :---------: | :---------------: | :----: | :----------: | :------------: |\n| 2026-10-29 | 10:57:38.04 |       0.42        |   r    |   6 * 600    | 19.74 +/- 0.07 |\n| 2026-10-29 | 12:02:02.32 |       0.46        |   i    |   6 * 600    | 19.74 +/- 0.19 |\n\nFurther optical follow-up observations are encouraged.\n\nThe PKU 60cm Telescope is operated by the Department of Astronomy, Peking University. The PKU HiTF group is dedicated to rapid follow-up observations of high-energy transients.",
  "circularId": 46090
}