The Cow: discovery of a luminous, hot and rapidly evolving transient

We present the ATLAS discovery and initial analysis of the first 18 days of the unusual transient event, ATLAS18qqn/AT2018cow. It is characeterized by a high peak luminosity (\sim 1.7\times10^{44} erg s^{-1}), rapidly evolving light curves (>5 mag rise in \sim3 days), hot blackbody spectra, peaking at \sim27000 K that are... Show more