CWISE J014611.20-050850.0AB: The Widest Known Brown Dwarf Binary in the Field
Abstract
While stars are often found in binary systems, brown dwarf binaries are much rarer. Brown dwarf--brown dwarf pairs are typically difficult to resolve because they often have very small separations. Using brown dwarfs discovered with data from the Wide-field Infrared Survey Explorer (WISE) via the Backyard Worlds: Planet 9 citizen science project, we inspected other, higher resolution, sky surveys for overlooked cold companions. During this process we discovered the brown dwarf binary system CWISE J01460508AB, which we find has a very small chance alignment probability based on the similar proper motions of the components of the system. Using follow-up near-infrared spectroscopy with Keck/NIRES, we determined component spectral types of L4 and L8 (blue), making CWISE J01460508AB one of only a few benchmark systems with a blue L dwarf. At an estimated distance of 40 pc, CWISE J01460508AB has a projected separation of 129 AU, making it the widest separation brown dwarf pair found to date. We find that such a wide separation for a brown dwarf binary may imply formation in a low-density star-forming region.
Cite
@article{arxiv.2202.02315,
title = {CWISE J014611.20-050850.0AB: The Widest Known Brown Dwarf Binary in the Field},
author = {Emma Softich and Adam C. Schneider and Jennifer Patience and Adam J. Burgasser and Evgenya Shkolnik and Jacqueline K. Faherty and Dan Caselden and Aaron M. Meisner and J. Davy Kirkpatrick and Marc J. Kuchner and Jonathan Gagne and Daniella Bardalez Gagliuffi and Michael C. Cushing and Sarah L. Casewell and Christian Aganze and Chih-Chun Hsu and Nikolaj Stevnbak Andersen and Frank Kiwy and Melina Thevenot and The Backyard Worlds and : and Planet 9 Collaboration},
journal= {arXiv preprint arXiv:2202.02315},
year = {2022}
}
Comments
Accepted for publication in ApJ Letters