GCN Circular 39858

Margarita Pereyra (UNAM), Rosa L. Becerra (U Roma), Stéphane Basa (UAR Pytheas), William H. Lee (UNAM), Jean-Luc Atteia (IRAP), Dalya Akl (AUS), Camila Angulo (UNAM), Sarah Antier (OCA), Nathaniel R. Butler (ASU), Jean-Grégoire Ducoin (CPPM), Damien Dornic (CPPM), Francis Fortin (IRAP), Noémie Globus (UNAM), Kin Ocelotl López (UNAM), Diego López-Cámara (UNAM), Francesco Magnani (CPPM), Enrique Moreno Méndez (UNAM), Ny Avo Rakotondrainibe (LAM), Benjamin Schneider (LAM), and Antonio de Ugarte Postigo (LAM) report:

We imaged the field of the Einstein Probe source EP J120944.2+585060 (Sun et al., GCN Circ. 39834

) possibly associated with FRB 250316A (ID=439373176) detected by CHIME/FRB (Mason et al., ATel #17081 with the DDRAGO wide-field imager on the COLIBRÍ telescope at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir in Mexico.

We observed the field centred in the position of EP J120944.2+585060 from 2025-03-23 08:23:56 to 12:32:11 UTC (6.99 to 7.17 days after the discovery of FRB 250316A) and obtained 2.82 hrs of exposure in the i filter. The data were coadded with custom software and analyzed in STDWeb/STDPipe (Karpov 2021), with photometric calibration against Pan-STARRS DR1 and image subtraction against Pan-STARRS DR2. Our photometry is in the AB system and is not corrected for Galactic extinction.

Consistent with previous reports (Becerra et al. ATel #17082, Niuno et al. ATel #17084, Hashimoto et al. ATel #17095, Aryan et al. Circ. GCN 39839

, Yang et al. ATel #17101, Becerra et al. GCN 39843

Loading...

 

 

and Becerra et al. GCN 39853

Loading...

 

 

), we do not detect any uncatalogued source to an estimated 5-sigma upper limit of

i > 23.6

We warmly thank the COLIBRÍ and DDRAGO engineering teams and the staff of the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir.