TITLE:   GCN CIRCULAR
NUMBER:  24357
SUBJECT: LIGO/Virgo S190426c: ZTF pre-detections of Gaia19bpm AT2019ehs
DATE:    19/04/30 18:36:11 GMT
FROM:    Igor Andreoni at Caltech  <igor.andreoni@gmail.com>

Igor Andreoni (Caltech), Eric Bellm (UW) report on behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations

 

We searched for Zwicky Transient Facility (ZTF) detections associated with Gaia19bpm AT2019ehs (Kostrzewa-Rutkowska et al., GCN 24355) in the archive of ZTF alerts.  A transient, dubbed ZTF19aaphkxx, was found at the location of Gaia19bpm.  The transient was first detected in public ZTF data starting from 2019-04-08 (g = 18.66 +- 0.14) and it peaked around 2019-04-15 (g = 17.98 +- 0.08).

 

The optical transient was detected days before the gravitational wave event S190426c (LIGO and Virgo Collaboration, GCN 24237), therefore we exclude an association between Gaia19bpm AT2019ehs and S190426c.

 

 

ZTF and GROWTH are worldwide collaborations 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. ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341. GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949. Alert distribution service provided by DIRAC@UW (Patterson et al. 2019).