VTC J095517.5+690813: A radio transient from an accretion-induced collapse of a white dwarf?

Abstract

We investigate a possibility that a recently reported radio transient in M81, VTC J095517.5+690813, is caused by an accretion-induced collapse of a white dwarf. It became bright in radio but no associated optical transient was discovered. The accretion-induced collapse is predicted to be radio bright but optically faint, satisfying the observed property. We compare predicted radio emission from the accretion-induced collapse with that of VTC J095517.5+690813 and show that it can be reasonably explained by the accretion-induced collapse. Although it is difficult to firmly conclude that VTC J095517.5+690813 is an accretion-induced collapse, our study shows that radio-bright transients without an optical counterpart could still be related to stellar deaths.