A new submm source within a few arcseconds of $α$ Centauri: ALMA discovers the most distant object of the solar system

R. Liseau, W. Vlemmings, E. O'Gorman, E. Bertone, M. Chavez, V. De la Luz

Published 2015-12-08Version 1

The understanding of the formation of stellar and planetary systems requires the understanding of the structure and dynamics of their outmost regions, where large bodies are not expected to form. Serendipitous searches for Sedna-like objects allows the observation of regions that are normally not surveyed. The Atacama Large Millimeter/submillimeter Array (ALMA) is particularly sensitive to point sources and it presents currently the only means to detect Sedna-like objects far beyond their perihelia. ALMA observations 10 months apart revealed a new blackbody point source that is apparently comoving with $\alpha$ Cen B. We exclude that source to be a sub-/stellar member of the $\alpha$ Centauri system, but argue that it is either an extreme TNO, a Super-Earth or a very cool brown dwarf in the outer realm of the solar system.