VLBI Detection and Astrometry for AT2018cow

ATel #11900; M. Bietenholz (York U., Canada, & HartRAO/SARAO, South Africa), R. Margutti (NWU, USA), K. Alexander (CfA, USA), M. Argo (U. Central Lancashire, UK), N. Bartel (York U., Canada), D. Coppejans (NWU, USA), M. Drout (Carnegie, USA), T. Eftekhari (CfA, USA), C. Guidorzi (U. Ferrara, Italy), D. Milisavljevic (Purdue U., USA), G. Terreran, (NWU, USA)
on 31 Jul 2018; 14:58 UT
Credential Certification: Michael Bietenholz (mbieten@yorku.ca)

Tweet

We obtained 22-GHz VLBI observations of AT2018cow with the NRAO VLBA and Effelsberg telescopes. The midpoint of the observations was 2018 July 8.1 UT. We detect the source with a total flux density of ~5 mJy. We obtain a preliminary position of RA = 16h 16m 00.2242s, dec = 22d 16' 04.890" with an estimated uncertainty of 60 micro-arcsec. Our position is more accurate than the previously reported one from e-MERLIN (Atel #11819) but only 3.2 milliarcsecond different, and therefore consistent within the estimated uncertainties. The position is based that of the phase-reference source, JVAS J1619+2247.