Igor Andreoni (Caltech), Danny Goldstein (Caltech), Dougal Dobie (University of Sydney/CSIRO), Mansi M. Kasliwal (Caltech)
report on behalf of the GROWTH (Global��Relay��of Observatories Watching Transients Happen) collaboration
We report the discovery of an optical transient spatially coincident with AT2019osy (Stewart et al., GCN #25487), a rising radio source identified with ASKAP during the follow-up of the gravitational wave event S190814bv (GCN #25324).
The optical transient was automatically detected in public data obtained by the DESGW team (GCN #25336, GCN #25360, GCN #25373, GCN #25398) during the follow-up of S190814bv under the NOAO target of opportunity program 2019B-0372 (PI Soares-Santos). The data were processed using the image subtraction pipelines described in Goldstein, Andreoni et al. (2019) and Andreoni, Goldstein et al. (2019).
On the last night of DECam observations (MJD 58716.26) the optical transient was detected at preliminary magnitude i=22.3.
GROWTH is a worldwide collaboration comprising of Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY, Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IIT-B, India; IIA, India; LJMU, UK; TTU, USA; USyd, Australia; and SDSU, USA. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949.
We gratefully acknowledge Amazon, Inc. for a generous grant that funded our use of the Amazon Web Services cloud computing infrastructure to process the DECam data.