{
  "circularId": 45885,
  "submittedHow": "web",
  "body": "Yacheng Kang (PKU), Qiang Wang (PKU), Ruize Shi (PKU), Chenxi Bao (PKU), Xinmiao Zhao (PKU), Yuhan Yao (PKU), and Fangzhou Ren (PKU) report on behalf of the PKU HiTF (High-energy Transients Follow-up) group:\n\nWe observed the field of EP261006a (Lao et al., GCN 45826; T0 = 2026-10-06T17:49:57), which has been classified as a possible TDE (Eyles-Ferris et al., GCN 45831; Jiang et al., GCN 45833), using the PKU 60cm telescope at Xinglong Observatory, NAOC. Observations were conducted over multiple epochs on 2026 October 7 and 8, approximately 21–49 hours after the EP-WXT detection, in the g, r, and i bands.\n\nIn the stacked images, we clearly detect the optical counterpart in the difference images at a position consistent with that of AT 2026aetp (Eyles-Ferris et al., GCN 45831; Jiang et al., GCN 45833; Wu et al. GCN 45852; Bochenek et al., GCN 45853; Chen et al. GCN 45854; Zhang et al., GCN 45877; Bochenek et al., GCN 45883). 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| 2026-10-07 | 13:55:42 |       0.88        |   g    |   12 * 600   | 18.76 +/- 0.03 |\n| 2026-10-07 | 16:02:32 |       0.94        |   r    |   4 * 600    | 19.07 +/- 0.04 |\n| 2026-10-07 | 17:43:52 |       1.02        |   r    |   6 * 600    | 19.02 +/- 0.04 |\n| 2026-10-07 | 18:49:21 |       1.08        |   i    |   11 * 600   | 19.23 +/- 0.06 |\n| 2026-10-08 | 13:21:12 |       1.86        |   g    |   12 * 600   | 18.46 +/- 0.03 |\n| 2026-10-08 | 15:23:32 |       1.92        |   r    |   7 * 600    | 18.79 +/- 0.04 |\n| 2026-10-08 | 16:57:40 |       1.97        |   r    |   3 * 600    | 18.79 +/- 0.04 |\n| 2026-10-08 | 17:29:48 |       2.03        |   i    |   12 * 600   | 19.05 +/- 0.04 |\n\nFurther analysis and follow-up observations are ongoing.\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.",
  "eventId": "EP261006a",
  "createdOn": 1791637308837,
  "eventType": [
    "X-ray Transient",
    "Optical Transient"
  ],
  "format": "text/markdown",
  "subject": "EP261006a / AT 2026aetp: Multiband optical follow-up with the PKU 60cm Telescope",
  "submitter": "Y.C. Kang at Peking University <yckang@stu.pku.edu.cn>"
}