{
  "circularId": 44810,
  "version": 2,
  "createdOn": 1780516727835,
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of A. Bochenek at Liverpool John Moores University <a.m.bochenek@2023.ljmu.ac.uk>",
  "subject": "EP260602a: Liverpool Telescope optical upper limits",
  "eventId": "EP260602a",
  "submittedHow": "web",
  "format": "text/plain",
  "body": "A. Bochenek, D. A. Perley, J. L. Wise (LJMU), report:\n\nWe observed the field of EP260602a (Li et al., GCN 44770) using the IO:O optical camera on the 2m robotic Liverpool Telescope. We obtained multiple 120s exposures in SDSS gri filters, starting at 2026-06-02 21:15:26 UT, approximately 13.07 hours after trigger. The observations were interrupted and consequently resumed due to weather conditions and telescope tracking issues; some exposures needed to be discarded.\n\nWe do not detect any sources at the position of the counterpart (Xu et al., GCN 44781, Li et al., GCN 44794; also Watson et al., GCN 44790; He et al., GCN 44798, Malesani et al., GCN 44807) down to the 3 sigma limiting magnitudes of:\n\n| MJD (mid)    | T_mid-T_0    | Exp. Time    | Filter       | Mag limit. (AB) |\n| ------------ | ------------ | ------------ | ------------ | --------------- | \n| 61193.93925  | 14.34 h      | 600 s        | g            |  > 21.8      |\n| 61193.91413  | 13.75 h      | 960 s        | r            |  > 22.1      |\n| 61194.11373  | 18.54 h      | 720 s        | i            |  > 21.9      |\n\nThe stacked exposures were subtracted from PanSTARRS reference imaging using custom PSF-matching image subtraction code utilising Swarp, SourceExtractor, and PSFex. The photometry is in the AB magnitude system, was calibrated using nearby PanSTARRS secondary standards and was not corrected for extinction.",
  "submitter": "A. Bochenek at Liverpool John Moores University <a.m.bochenek@2023.ljmu.ac.uk>",
  "editedOn": 1780582639285
}