Possible Disintegration of Main-belt Asteroid 2008 BJ₂₂

Abstract Active asteroids are a mysterious population of objects on asteroid-like orbits that display comet-like activity produced by a diverse variety of mechanisms, providing glimpses of the ongoing evolution of the asteroid belt and near-Earth objects. We report the identification of a new active asteroid 2008 BJ22, from images obtained by the Subaru Telescope in 2008. The object was not detected in earlier Canada–France–Hawaii Telescope images obtained in 2005 down to a 3σ limiting magnitude of m r ∼ 24, corresponding to a V-band absolute magnitude of H V > 18.4, more than 3 mag fainter than the absolute magnitude computed from 2008 data. Analysis of later images obtained by the Dark Energy Camera on the 4.0 m Victor M. Blanco Telescope in 2013 set the object’s current V-band absolute magnitude at H V > 19.3. These results suggest that 2008 BJ22 was discovered in an active state in 2008 January.