A Unicorn in Monoceros: the $3M_{\odot }$ dark companion to the bright, nearby red giant V723 Mon is a non-interacting, mass-gap black hole candidate

T. Jayasinghe, K. Z. Stanek, Todd A. Thompson +18

We report the discovery of the closest known black hole candidate as a binary companion to V723 Mon. V723 Mon is a nearby ($d\sim 460\mathrm{pc}$), bright ($V\simeq 8.3$~mag), evolved (…