CK Vul as a Candidate Eruptive Stellar Merging Event

Abstract

CK Vul (Nova Vul 1670) is one of the most mysterious objects among erupting stellar objects. Past studies have suggested that CK Vul is a final helium-flash object resembling V605 Aql and V4334 Sgr (Sakurai's object). The peculiar outburst light curve of CK Vul, however, had no similar counterpart among the known eruptive objects. Furthermore, the presence of hydrogen in the proposed remnant seems to contradict with the final helium-flash scenario. We propose that the peculiarities of CK Vul can be naturally understood if we consider a merging of main-sequence stars, following a new interpretation by Soker and Tylenda (astro-ph/0210463), which was proposed to explain the peculiar eruptive object V838 Mon. In this case, the 1670 outburst of CK Vul may be best understood as a V838 Mon-like event which occurred in our vicinity.