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GCN Circular 24540

LIGO/Virgo S190510g: DECam-GROWTH optical counterpart candidate DG19qcso
2019-05-14T14:27:18Z (5 years ago)
Daniel Goldstein at Caltech <>
Erik Kool (OKC), Daniel A. Goldstein (Caltech), and Igor Andreoni (Caltech) on behalf of the Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations:

As part of the follow up effort described in Andreoni et al. (2019, GCN #24467) of the high-probability region of the LALInference skymap of gravitational wave source S190510g (LIGO/VIRGO Collaboration, GCN #24448) with the Dark Energy Camera (DECam), we report the detection of an additional optical counterpart candidate, DS19qcso. The transient was detected ~2��� offset to the N of the nucleus of its host galaxy through difference imaging using an automated pipeline, and appeared in g and r-band, but not in z-band. Coordinates and observed magnitudes (at jday 2458614.5) are as follows:

Coordinates: 88.208631 -30.381382 (05:52:50.07 -30:22:53.0)
g mag: 21.57 (0.13)
r mag: 22.69 (0.21)
z mag: > 21.9

The host galaxy is identified as 2MASXi J0552500-302254, but no host redshift is available. From Pan-STARRS imaging, we measure the host galaxy to be 15������ across. Postage stamp images of the candidate can be viewed at the following link:

We thank the CTIO staff, Steve Heathcote, Kathy Vivas, Tim Abbott, for facilitating these Target of Opportunity observations.

GROWTH is a worldwide collaboration comprising 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 and USyd, Australia. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. An optimized schedule was generated using the ToO marshal system (Coughlin et al. 2019). Alert filtering and follow-up co-ordination is being undertaken by the GROWTH marshal system (Kasliwal et al. 2019).

This research draws upon DECam data as distributed by the Science Data Archive at NOAO. NOAO is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) collaboration.

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