TITLE:   GCN CIRCULAR
NUMBER:  37808
SUBJECT: GRB 241017A: GROWTH-India Telescope optical upper limit
DATE:    24/10/18 06:01:57 GMT
FROM:    Varun Bhalerao at IIT Bombay <varunb@iitb.ac.in>

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

We observed the field of the GRB 241017A (SVOM/ECLAIRs team, GCN 37799) with the 0.7m GROWTH-India Telescope (GIT). With the current GIT camera with a field of view of 11' x 7', observed 12 tiles to cover the area for the statistical and systematic uncertainity regions mentioned in GCN 37799.

Obserations started at 2024-10-17 19:02:04 UT, about 15.1 hours after the SVOM/ECLAIRs trigger. Each tile had image of 360s in r' filter. We did not detect any new source in our images. In particular, we do not find any source in the error circle of uncatalogued source at 356.1750d, +15.6574d reported in the automated Swift follow-up (GCN #37800, https://gcn.gsfc.nasa.gov/other/21723.counterpart). Due to the proximity to the bright moon (~28 deg), the images were shallower than usual.

| MJD mid     | RA      | Dec    | Lim Mag (5-sigma) |
| ----------- | ------- | ------ | ----------------- |
| 60600.79518 | 356.305 | 15.731 | 19.2  |
| 60600.79972 | 356.637 | 15.726 | 19.3  |
| 60600.80424 | 356.238 | 15.725 | 19.2  |
| 60600.81313 | 356.515 | 15.894 | 19.3  |
| 60600.81766 | 356.367 | 15.892 | 19.1  |
| 60600.82209 | 356.382 | 15.563 | 19.5  |
| 60600.82654 | 356.248 | 15.559 | 19.5  |
| 60600.83556 | 356.101 | 15.723 | 19.1  |
| 60600.84000 | 356.511 | 15.561 | 19.4  |
| 60600.84452 | 356.096 | 15.892 | 19.1  |
| 60600.84894 | 356.376 | 15.729 | 19.4  |
| 60600.85339 | 356.513 | 15.734 | 19.6  |

The magnitude are 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/.