[vsnet-grb-info 23463] LIGO/Virgo S190828j: No Counterparts in DDOTI/OAN Optical Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25562
SUBJECT: LIGO/Virgo S190828j: No Counterparts in DDOTI/OAN Optical Observations
DATE:    19/08/30 03:17:58 GMT
FROM:    Emma Margarita Pereyra Talamantes at IA-UNAM Ensenada  <mpereyra at astro.unam.mx>

Margarita Pereyra <mpereyra at astro.unam.mx> (UNAM), Simone Dichiara
(GSFC/UMD), Alan M. Watson (UNAM), Nat Butler (ASU), Rosa L. Becerra
(UNAM), Diego Gonzalez (UNAM), Alexander Kutyrev (GSFC/UMD), William H. Lee
(UNAM), Eleonora Troja (GSFC/UMD), Gabriele Minervini (INAF/IAPS-Rome)  and
Tanner Wolfram (ASU) report:

We observed LIGO/Virgo S190828j event (Minazzoli et al., GCN #25497) with
the DDOTI/OAN wide-field imager at the Observatorio Astronomico Nacional on
Sierra San Pedro Martir (http://ddoti.astroscu.unam.mx) from 2019-08-28
08:00 to 2019-08-28 11:57 UTC (1.4 to 5.4 hours after the event).

We observed approximately 231 square degrees of the sky, with four
pointings centered on 22:10:13.126 +45:18:17.26, 21:45:30.680 +39:42:01.13,
21:25:37.437 +32:53:21.57 and 21:07:43.518 +24:13:55.90. We obtained about
21, 16, 18 and 86 minutes total exposure on each pointing, respectively.
These regions include about 35% of the 2D probability in the current
BAYESTAR map.

We calibrated our images against the APASS catalog. Our 10-sigma limiting
magnitude are typically between w = 19.2 and w = 19.8.

Comparing our 10-sigma detections against the USNO-B1 catalog, we detect no
uncataloged sources with significant fading.

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

-- 
*Dr. Margarita Pereyra *

*FFTF, Schlumberger Foundation Alumnae*
----------------------------------------------------------------------------------------------------------------

*Catedrático Conacyt*

*Instituto de Astronomía de la UNAM,*

*Km. 107 Carretera Tijua**na-Ensenada, *

*Ensenada Baja California, México. C.P. 22860*

Oficina: 405

Skype: margarita-pereyra