TITLE: GCN CIRCULAR NUMBER: 39472 SUBJECT: EP250223a: GROWTH-India Telescope optical observations DATE: 25/02/25 19:15:48 GMT FROM: V. Swain at IIT Bombay vishwajeet.s@iitb.ac.in
A.P. Saikia, T. Mohan, V. Swain, V. Bhalerao (IITB), D. Eappachen, G.C. Anupama, S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:
We observed the field of EP250223a reported by EP-WXT (Lian et al., GCN 39429) with the 0.7m GROWTH-India Telescope (GIT). We started the observation at 2025-02-23T17:05:58 UT, i.e., 2.02 hours after the EP trigger. We obtained a single exposure of 420 seconds each in r' and g' filters. We clearly detected the afterglow in our image at the position given by NOT (Hauptmann et. al., GCN 39436). The photometry result follows as:
| MJD (mid) | tmid-t0 (hours) | Filter | Total Exposure (s) | Magnitude (AB) | Limiting Magnitude | | ----------------- | ----------- |------- | ------------------ | -------------- | ------ | | 60729.714907 | 2.08 | r' | 1x420 | 19.18 +/- 0.18 | 19.66 | | 60729.720081 | 2.15 | g' | 1x420 | - | 19.62 |
Our result is consistent with Hauptmann et al., (GCN 39436), Wu et al., (GCN 39439), Péréz-Fournon et al., (GCN 39440), Izzo et al., (GCN 39441), Xin et al., (GCN 39445), Guo et al., (GCN 39447).
The measurement is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction.
The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.
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