GCN Circular 37545
Subject
EP240918a: Optical upper limits with Kinder observations
Event
Date
2024-09-18T15:59:55Z (a year ago)
From
Janet Chen at National Central University <janetstars@gmail.com>
Via
Web form
A. K. H. Kong (NTHU), A. Aryan, T.-W. Chen, C.-H. Lai, H.-Y. Hsiao, C.-S. Lin (all NCU), S. Yang (HNAS), S. J. Smartt (Oxford/QUB), A. Sankar. K, Y. J. Yang, W.-J. Hou, C.-C. Ngeow, M.-H. Lee, Y.-C. Pan, H.-C. Lin, J.-K. Guo (all NCU), H.-W. Lin (UMich), H. F. Stevance, S. Srivastav, J. Gillanders, L. Rhodes (all Oxford), M. Nicholl, M. Fulton, T. Moore, K. W. Smith, C. Angus, A. Aamer (all QUB), A. Schultz and M. Huber (both IfA, Hawaii) report:
We observed the field of the fast X-ray transient EP240918a (Zhang et al., GCN 37541) using the 40cm SLT at Lulin Observatory in Taiwan as part of the Kinder collaboration (Chen & Yang et al., 2024arXiv240609270C). The first SLT epoch of observations started at 13:43 UTC on the 18th of September 2024 (MJD = 60571.571), 2.30 hrs after the EP trigger.
We utilized the astroalign (Beroiz et al., 2020, A&C, 32, 100384) and astropy (Astropy Collaboration et al., 2022, ApJ, 935, 167) packages to align and stack the individual frames. In the stacked frames, we do not detect any evidence of a new uncataloged source within the FXT error circle of 20" reported by Zhang et al. (GCN 37541