TITLE: GCN CIRCULAR NUMBER: 25915 SUBJECT: LIGO/Virgo S190930s: no counterpart candidates in SAGUARO/CSS observations DATE: 19/10/01 23:37:17 GMT FROM: Kerry Paterson at Northwestern 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.