TITLE:   GCN CIRCULAR
NUMBER:  26752
SUBJECT: LIGO/Virgo S200114f: No Counterparts in DDOTI/OAN Optical Observations
DATE:    20/01/14 22:38:35 GMT
FROM:    Simone Dichiara at UMCP/NASA/GSFC  <dichiara@umd.edu>

Simone Dichiara (GSFC/UMD), Eleonora Troja (GSFC/UMD), Alan M. Watson
(UNAM), Nat Butler (ASU), Alexander Kutyrev (GSFC/UMD), Margarita Pereyra
(UNAM), Rosa L. Becerra (UNAM), Diego Gonzalez (UNAM), William H. Lee
(UNAM) and Tanner Wolfram (ASU) report:

We observed LIGO/Virgo S200114f (Chatterjee et al, GCN Circ. 26734) 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
2020-01-14 UTC.

We tiled the LVC localization with four pointings spanning a region of
approximately 13.6 degrees in RA and 20.4 degrees in DEC centered on the
peak of the probability map at 07:20:09 +15:42:50 2000. This region covers
about 280 square degrees and includes about 80% of the probability in the
map. We observed from 2020-01-14 02:40 UTC to 2020-01-14 12:00 UTC (from 29
minutes to 9.7 hours after the event) obtaining exposures of 53 to 65
minutes across the field in the w filter.

We calibrate our images against the APASS catalog. Our 10-sigma limiting
magnitude are typically between w = 18.9 and w = 19.5.

We detect no uncatalogued sources within the observed field with
significant fading or brightening.

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