GCN Circular 45885
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:
We 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.
In 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.
The observation log is summarized below following the time sequence:
| Date | Start_UT | T_mid - T0 (days) | Filter | Exposure (s) | Magnitude (AB) |
|---|---|---|---|---|---|
| 2026-10-07 | 13:55:42 | 0.88 | g | 12 * 600 | 18.76 +/- 0.03 |
| 2026-10-07 | 16:02:32 | 0.94 | r | 4 * 600 | 19.07 +/- 0.04 |
| 2026-10-07 | 17:43:52 | 1.02 | r | 6 * 600 | 19.02 +/- 0.04 |
| 2026-10-07 | 18:49:21 | 1.08 | i | 11 * 600 | 19.23 +/- 0.06 |
| 2026-10-08 | 13:21:12 | 1.86 | g | 12 * 600 | 18.46 +/- 0.03 |
| 2026-10-08 | 15:23:32 | 1.92 | r | 7 * 600 | 18.79 +/- 0.04 |
| 2026-10-08 | 16:57:40 | 1.97 | r | 3 * 600 | 18.79 +/- 0.04 |
| 2026-10-08 | 17:29:48 | 2.03 | i | 12 * 600 | 19.05 +/- 0.04 |
Further analysis and follow-up observations are ongoing.
The 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.