GCN Circular 43774
Subject
EP260214b: 1.3m DFOT optical upper limit
Event
Date
2026-02-17T17:26:03Z (6 days ago)
From
Debalina Kar at ARIES <kardebalina2000@gmail.com>
Via
Web form
Debalina Kar, Pankaj Pawar, Anshika Gupta, Dhruv Jain and Kuntal Misra (ARIES) report:
We observed the field of EP260214b detected by EP/WXT (Yang et al., GCN 43744) with the 1.3m Devasthal Fast Optical Telescope (DFOT), located at the Devasthal Observatory of the Aryabhatta Research Institute of Observational Sciences (ARIES), India. The observations began on 2026-02-17 at 00:15:22 UT, approximately 50.82 hours after the trigger. We obtained multiple exposures of 300 s each in the R filter. A total of 15 frames were aligned and stacked to improve the signal-to-noise ratio. In the stacked frame we do not detect any optical counterpart within the error box of EP/WXT (Yang et al., GCN 43760) as reported by He et al. (GCN 43745). This is consistent with the non-detection reported by Aryan et al. (GCN 43762). We derive the following 3-sigma upper limit from the stacked image:
Date (UT) Start Time T_start–T0 (hr) Filter Exposure Magnitude
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2026-02-17 00:15:22 ~50.82 R 300 s × 15 > 22.40
The non-detection is consistent with the detection and fading behavior reported by Watson et al. (GCN 43747), Floch et al. (GCN 43749), Pérez-Fournon et al. (GCN 43750), Russeil et al. (GCN 43752), Li et al. (GCN 43755), Becerra et al. (GCN 43758), as well as with the upper limit reported by Vijaykumar et al. (GCN 43757).
The reported magnitude is not corrected for Galactic extinction. Photometric calibration was performed using standard stars from the Pan-Starrs catalogue.