TITLE:   GCN CIRCULAR
NUMBER:  36099
SUBJECT: LIGO/Virgo/KAGRA S240413p: No Counterparts in DDOTI/OAN Optical Observations
DATE:    24/04/14 20:37:50 GMT
FROM:    Rosa L. Becerra at Tor Vergata, Roma <rbecerra@astro.unam.mx>

Rosa L. Becerra (Tor Vergata, Roma), Alan M. Watson (UNAM), Eleonora Troja (Tor Vergata, Roma), Nat Butler (ASU), Simone Dichiara (Penn State University), William H. Lee (UNAM), Alexander Kutyrev (GSFC/UMD), Tsvetelina Dimitrova (ASU), Keneth Garcia Cifuentes (UNAM), Camila Angulo Valdez (UNAM), Margarita Pereyra (UNAM) and Océlotl Lopez (UNAM) report:

We observed LIGO/Virgo/KAGRA S240413p (GCN #36075) with the DDOTI/OAN wide-field imager at the Observatorio Astronomico Nacional on Sierra San Pedro Martir (http://ddoti.astroscu.unam.mx) on the night of 2024-04-13 UTC.

We tiled the LVKC localization with one pointing centred on 165.541667 +11.866667  (J2000). The combined field covers about 48 square degrees and includes about 41% of the probability in the current BAYESTAR map. 

We observed from 2024-04-13 05:58 UTC to 2024-04-13 09:29 UTC (from T+3.6 to
T+7.1 hours after the event) obtaining exposures of 2.4 hours across
the field in the w filter, with 10-sigma limiting magnitudes of w = 20.2 to
w = 20.9. 

Comparing our observations to the USNO-B1 and PanSTARRS PS1 DR2 catalogs we
detect no uncatalogued sources within the observed field to our 10-sigma
limit. We observe the galaxy WISEA J105644.96+105455.6 (GCN #36080) without any evidence of flare activity.

Further observations are planned.

We thank the staff of the Observatorio Astronomico Nacional in San Pedro
Martir.
