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GCN Circular 24172

LIGO/Virgo S190425z: SAGUARO follow-up observations
2019-04-25T10:59:32Z (5 years ago)
Michael J. Lundquist at University of Arizona <>
Michael J. Lundquist (UA), Kerry Paterson, Wen-fai Fong (Northwestern),
David J. Sand (UA), Stefano Valenti (UC Davis), Sheng Yang (INAF-OAPd, UC
Davis), Sam Wyatt (UA), Eric Christensen, Alex Gibbs, Frank Shelly
(UA/LPL), Jennifer Andrews (UA) report:

We initiated observations of 12 fields (each 2.26 x 2.26 deg^2) within the
LVC localization region for the GW trigger S190425z (LVC Circ 24168)
starting on 2019-04-25 9:01 UT. SAGUARO* uses the 1.5m Catalina Sky Survey
telescope on Mt. Lemmon, AZ and its 5 deg^2 imager to tile the highest
probability regions of the LVC localization that are accessible from
southern Arizona in order to search for electromagnetic counterparts to
gravitational wave events. The typical limiting magnitudes of single
pointings are G~21 mag (calibrated to Gaia DR2). Below are the field
centers observed. Any interesting transient candidates will be reported as
soon as possible.

244.2855 20.9792
245.7690 18.7708
247.2150 16.5625
242.7630 23.1875
240.4020 25.3958
237.9450 27.6042
235.4790 27.6042
237.9870 25.3958
240.3945 23.1875
247.9245 14.3541
249.3165 12.1458
235.3845 29.8125

*SAGUARO stands for Searches After Gravitational-waves Using ARizona's
Observatories. It is a partnership between the University of Arizona and
Northwestern University.
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