GCN Circular 39444
Subject
LIGO/Virgo/KAGRA S250223dk: DDOTI Upper Limits on the Optical Counterpart
Date
2025-02-24T04:53:21Z (8 months ago)
From
Alan Watson at UNAM <alan@astro.unam.mx>
Via
Web form
Alan M. Watson (UNAM), William H. Lee (UNAM), Océlotl L ópez (UNAM), Camila Angulo Valdez (UNAM), Rosa L. Becerra (U Roma), Nat Butler (ASU), Simone Dichiara (Penn State University), Tsvetelina Dimitrova (ASU), Alexander Kutyrev (GSFC/UMD), and Margarita Pereyra (UNAM), and Eleonora Troja (U Roma) report:
We imaged the field of the Swift/BAT-GUANO trigger possibly associated with LIGO/Virgo/KAGRA S250223dk (GCN Circ. 39443) with the DDOTI wide-field imager at the Observatorio Astronómico Nacional on the Sierra de San Pedro Mártir in Mexico (http://ddoti.astroscu.unam.mx).
We observed the whole BAT error region from 2025-02-24 03:56 UTC to 04:24 UTC (15.9 to 16.4 hours after the GW event) at extremely high airmass. We obtained a total exposure of 24 minutes.
Comparing our observations to the USNO-B1 and PanSTARRS PS1 DR2 catalogues, we detect no uncatalogued sources within the observed BAT error region to a 5-sigma AB limiting magnitude of
w > 20.0.
Our photometry is in the AB system and is not corrected for Galactic extinction.
We thank the staff of the Observatorio Astronómico Nacional in San Pedro Mártir.