TITLE: GCN CIRCULAR NUMBER: 44952 SUBJECT: GRB 260604C: GRANDMA late observations with CFHT/MegaCam DATE: 26/06/16 13:14:53 GMT FROM: antier@ijclab.in2p3.fr Q. Bais (KNC), A. Bruna (KNC), L. Laumain (KNC), A. Delaplace (KNC), S. Antier (IJCLAB), M. Pillas (IAP), P. Hello (IJCLAB), M. Coughlin (UMN), L. Desrivieres (KNC) on behalf of GRANDMA and CM2 classroom of St Remy Lès Chevreuse: We conducted further follow-up observations of GRB 260604C (Fermi Team, GCN Circ. 44822, Gotz et al., GCN Circ. 44823) with the Canada-France-Hawaii Telescope/MegaPrime/MegaCam on 2026-06-10. We further detected the source and confirmed that the rebrightening episode ended on 2026-06-10. We posted some of our data in the public site group of the public ACME service Skyportal/ICARE https://skyportal-icare.ijclab.in2p3.fr/source/GCN-260604_202037. To access, one simply needs to create an account using your ORCID id. These measurements are aligned with all our previous GRANDMA measurements. We thanks the CFHT team for observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l’Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. We also acknowledge funding from the European Union’s Horizon Europe Research and Innovation Programme under Grant Agreement No 101131928 (ACME project). The observations are performed under the P7 campaign of GRANDMA to monitor SVOM alerts and LSST alerts from explosive fast transients filtered by BOOM/Babamul and FINK. 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 (kilonovacatcher.in2p3.fr). Astrophysics Center for Multimessenger studies in Europe is supported Skyportal/ICARE (contact camille.douzet@ijclab.in2p3.fr, skyportal.io). View this GCN Circular online at https://gcn.nasa.gov/circulars/44952. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...