TITLE:   GCN CIRCULAR
NUMBER:  40284
SUBJECT: EP250428b: GROWTH-India telescope optical upper limit
DATE:    25/04/30 07:54:42 GMT
FROM:    anirudhsalgundi@gmail.com

A. Salgundi (IITB), V. Swain (IITB), D. Eappachen (IIA), A.P. Saikia (IITB), V. Bhalerao (IITB), G.C. Anupama (IIA), S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:

We observed the field of the EP250428b (Liu et al., GCN #40277) with the 0.7m GROWTH-India Telescope (GIT). Observation started at 2025-04-29T18:21:59 UT, about 1.51 days after the trigger. We obtained single image of 360s in r' filter.

The following upper limit was obtained:


|MJD (mid)| Filter| Exposure (s)|	Limiting Magnitude (AB)|
| ----------------- | ----------- |------- | ------------------ |
60794.7652662038|	r'| 360|	20.5

The magnitude is calibrated against PanSTARRS DR1 (Chambers et al., 2016) and not corrected for Galactic extinction.

The upper limit is consistent with MASTER (Lipunov et al., GCN #40278), LAST (Konno et al., GCN #40281), SAO RAS (Moskvitin et., GCN #40282), SVOM/VT (Xin et al., GCN #40283).


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/.