GCN Circular 25915
Subject
LIGO/Virgo S190930s: no counterpart candidates in SAGUARO/CSS observations
Date
2019-10-01T23:37:17Z (5 years ago)
From
Kerry Paterson at Northwestern <kerry.paterson@northwestern.edu>
Kerry Paterson (Northwestern), Michael J. Lundquist, David J. Sand (UA), Wen-fai Fong, Jillian Rastinejad (Northwestern), Jennifer Andrews (UA), Sam Wyatt (UA), Eric Christensen, Alex Gibbs, Frank Shelly (UA/LPL), report on behalf of the SAGUARO collaboration:
We initiated observations of 12 fields (each 5 deg^2, totalling 60 deg^2) within the LVC localization region for the GW trigger S190930s (LVC Circ 25871) starting on 2019-10-01 02:09:22 UT (0.52 days after the GW trigger) with the 1.5m Catalina Sky Survey telescope on Mt. Lemmon, AZ.
Below are the field centers observed.
RA DEC
318.8895 7.7292
318.8895 9.9375
316.6665 9.9375
316.3965 12.1458
315.8490 14.3541
313.5840 14.3541
314.1615 12.1458
319.1415 5.5208
321.3495 3.3125
321.3495 5.5208
318.6330 12.1458
313.2915 16.5625
We have posted our pointings to the Treasure Map, and encourage others to do the same:
http://treasuremap.space/alerts?graceids=S190930s&pointing_status=all&alert_type=Initial
Performing image subtraction, we find no new transients within the 60 deg^2 searched down to a 3-sigma limit of G~21.3 AB mag (calibrated to Gaia DR2) relative to deep CSS reference images.
A more detailed description of SAGUARO can be found in Lundquist et al. 2019, ApJL, 881, 2. SAGUARO is supported by the National Science Foundation under Award Nos. AST-1909358 and AST-1908972.