GCN Circular 46006
Subject
EP261015a: Further optical observations with the 1.3m DFOT
Event
Date
2026-10-21T13:36:45Z (22 days ago)
From
pawarpankaj1492@gmail.com
Via
Web form
Pankaj Pawar, Yash Sharma, Anshika Gupta, Debalina Kar, Dhruv Jain, Kuntal Misra, Amit K Ror and Shashi B. Pandey (ARIES, Nainital, India) report:
We observed the field of EP261015a (Li et al., GCN 45956) and its candidate optical counterpart (Corcoran et al., GCN 45955) with the 1.3m Devasthal Fast Optical Telescope (DFOT), India, on 2026 October 20. Observations started at 19:07:22 UT. We obtained six 300-s exposures in the R filter.
We reduced and stacked the images using standard procedures. After archival Legacy Survey template subtraction, we find a tentative positive residual at the counterpart position. Our preliminary PSF photometry, using an empirical PSF constructed with AutoPhOT (Brennan & Fraser 2022, A&A, 667, A62), is:
Mid-time (UT) Tmid-T0 (d) Filter Exposure (s) Mag (AB)
2026-10-20 19:22:34 5.25484 R 6 x 300 22.30 +/- 0.24
T0 is 2026-10-15 13:15:36 UT (Li et al., GCN 45956). Photometry was calibrated against nearby stars using standardised synthetic Johnson–Cousins R magnitudes derived from Gaia DR3 XP spectra. Magnitudes are reported on the AB system using the zero-point conversion of Bessell & Murphy (2012, PASP, 124, 140), and are not corrected for Galactic extinction.
The uncertainty includes an allowance for tested subtraction systematics; additional uncertainty from residual galaxy contamination and the different science/template passbands may remain. We regard the measurement as tentative.
Our observation follows the optical rebrightening reported by Fortin et al. (GCN 45991). Further observations are encouraged to establish the subsequent evolution of the source.