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GCN Circular 41016

Subject

EP250702a/GRB250702 B,D,E: GRANDMA Upper Limit

Event

EP250702a

Date

2025-07-07T19:18:12Z (13 hours ago)

From

Dalya Akl at American Uni. SHJ <dalyaakl.d@gmail.com>

Via

Web form

D. Akl (AUS), K. Noysena, A. Manasanun (NARIT), M. Freeberg, R. Hellot (KNC), C. Andrade (UMN), W. Corradi (LNA), M. Pillas (Uliege), S. Antier (OCA/IJCLAB), N. Kochiashvili (AbAO), M. Lamoureux (UCLouvain), on behalf of GRANDMA:

We observed the field of EP250702a (GCN 40906

; associated with GRBs 250702/B/D/E) with GRANDMA and Kilonova Catcher and did not detect any optical counterpart.

All our measurements can be downloaded from: https://skyportal-icare.ijclab.in2p3.fr/public/sources/EP250702a/

All the data have been reduced by a single data processing pipeline, STDPipe (Karpov et al., 2022). Images obtained with the Sloan filters were calibrated using the PanSTARRS DR1 catalog. Images obtained with the Johnson-Cousin filters were calibrated using the Gaia DR3 Synphot catalog.

We use the SkyPortal application (skyportal.io) to monitor our observational campaign (Coughlin et al. 2023).

Our observations are consistent with previously reported measurements (refer to SkyPortal for a subset of GCN measurements we collected).

GRANDMA is a worldwide telescope network (grandma.ijclab.in2p3.fr) devoted to the observation of transients in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS 497, 5518). Kilonova-Catcher (KNC) is the citizen science program of GRANDMA (http://kilonovacatcher.in2p3.fr/).