AstroNote 2019-154

We are carrying out the "Pan-STARRS Search for Kilonovae" which is a focused search for intrinsically faint transients, or rapidly evolving transients in galaxies which are closer than 200 Mpc in the ongoing Pan-STARRS Near Earth Object surveys (see Smartt et al. AstroNote 2019-48 for details). 

In normal survey mode, Pan-STARRS takes 4 x 45s exposures in w, i or z each night reaching 5 sigma magnitudes of w<22, i<21 and z<20.5 in each frame (see Chambers et al. 2016, 1612.05560). 

We report the discovery of an intrinsically faint transient PS19hgw (AT2019wxt)  in the host galaxy  KUG 0152+311 , at a redshift of z = 0.036, or d = 143.9 Mpc (from NED).  The transient was discovered at MJD 58833.31 (2019-12-16.31) at mag i =  19.3 +/- 0.1. It is offset from the host by  0.5" S, 7.7" E ( a projected 6.7 kpc radius from the galaxy centre). At this distance the absolute magnitude is M_i = -16.6 (assuming m-M =35.8 and foreground exinction of  A_r = 0.153). Spectroscopic classification is encouraged. 

Information on all objects discovered by the "Pan-STARRS search for kilonovae" will be made available at http://star.pst.qub.ac.uk/ps1threepi/. We will release AstroNotes for all these candidates and encourage spectroscopic classification or photometric follow-up.  A finder is attached. 

We note that this is in the 80% contour of the skymap of the possible BNS gravitational wave source
S191213g (the LALInference.fits.gz, The LIGO Scientific Collaboration and the Virgo Collaboration, GCN 26402), was discovered after the merger time, and is at a distance consistent with the parameter 
estimation of LVC for this event. 

These discoveries are a byproduct of the Pan-STARRS NEO survey observations supported by the NASA Grants, including No. NNX14AM74G issued through the SSO Near Earth Object Observations Program.