A Caltech Library Service

CWISE J014611.20–050850.0AB: The Widest Known Brown Dwarf Binary in the Field

Softich, Emma and Schneider, Adam C. and Patience, Jennifer and Burgasser, Adam J. and Shkolnik, Evgenya and Faherty, Jacqueline K. and Caselden, Dan and Meisner, Aaron M. and Kirkpatrick, J. Davy and Kuchner, Marc J. and Gagné, Jonathan and Bardalez Gagliuffi, Daniella and Cushing, Michael C. and Casewell, Sarah L. and Aganze, Christian and Hsu, Chih-Chun and Andersen, Nikolaj Stevnbak and Kiwy, Frank and Thévenot, Melina (2022) CWISE J014611.20–050850.0AB: The Widest Known Brown Dwarf Binary in the Field. Astrophysical Journal Letters, 926 (2). Art. No. L12. ISSN 2041-8205. doi:10.3847/2041-8213/ac51d8.

[img] PDF - Published Version
Creative Commons Attribution.

[img] PDF - Accepted Version
Creative Commons Attribution.


Use this Persistent URL to link to this item:


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 J0146−0508AB, 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 J0146−0508AB one of only a few benchmark systems with a blue L dwarf. At an estimated distance of ∼40 pc, CWISE J0146−0508AB 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.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Softich, Emma0000-0002-1420-1837
Schneider, Adam C.0000-0002-6294-5937
Patience, Jennifer0000-0001-9004-803X
Burgasser, Adam J.0000-0002-6523-9536
Shkolnik, Evgenya0000-0002-7260-5821
Faherty, Jacqueline K.0000-0001-6251-0573
Caselden, Dan0000-0001-7896-5791
Meisner, Aaron M.0000-0002-1125-7384
Kirkpatrick, J. Davy0000-0003-4269-260X
Kuchner, Marc J.0000-0002-2387-5489
Gagné, Jonathan0000-0002-2592-9612
Bardalez Gagliuffi, Daniella0000-0001-8170-7072
Cushing, Michael C.0000-0001-7780-3352
Casewell, Sarah L.0000-0003-2478-0120
Aganze, Christian0000-0003-2094-9128
Hsu, Chih-Chun0000-0002-5370-7494
Andersen, Nikolaj Stevnbak0000-0003-4714-3829
Kiwy, Frank0000-0001-8662-1622
Thévenot, Melina0000-0001-5284-9231
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2022 January 3; revised 2022 January 31; accepted 2022 February 3; published 2022 February 17. The Backyard Worlds: Planet 9 team would like to thank the many Zooniverse volunteers who have participated in this project. We would also like to thank the Zooniverse web development team for their work creating and maintaining the Zooniverse platform and the Project Builder tools. This research was supported by NASA grant 2017-ADAP17-0067. This material is based upon work supported by the National Science Foundation under grant Nos. 2007068, 2009136, and 2009177. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, and NEOWISE, which is a project of the Jet Propulsion Laboratory/California Institute of Technology. WISE and NEOWISE are funded by the National Aeronautics and Space Administration. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. The Pan-STARRS1 Surveys (PS1) and the PS1 public science archive have been made possible through contributions by the Institute for Astronomy, the University of Hawaii, the Pan-STARRS1 Project Office, the Max Planck Society and its participating institutes, the Max Planck Institute for Astronomy, Heidelberg, and the Max Planck Institute for Extraterrestrial Physics, Garching, The Johns Hopkins University, Durham University, the University of Edinburgh, the Queen's University Belfast, the Harvard-Smithsonian Center for Astrophysics, the Las Cumbres Observatory Global Telescope Network Incorporated, the National Central University of Taiwan, the Space Telescope Science Institute, the National Aeronautics and Space Administration under grant No. NNX08AR22G issued through the Planetary Science Division of the NASA Science Mission Directorate, National Science Foundation grant No. AST-1238877, the University of Maryland, Eotvos Lorand University (ELTE), Los Alamos National Laboratory, and the Gordon and Betty Moore Foundation. Facility: Keck (NIRES). - Software: SpeXTool (Cushing et al. 2010); SPLAT (Burgasser & Splat Development Team 2017); CoMover (Gagné et al. 2021).
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
University of MarylandUNSPECIFIED
Eotvos Lorand University (ELTE)UNSPECIFIED
Los Alamos National LaboratoryUNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Subject Keywords:Brown dwarfs; L dwarfs
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Brown dwarfs (185); L dwarfs (894)
Record Number:CaltechAUTHORS:20220217-686840000
Persistent URL:
Official Citation:Emma Softich et al 2022 ApJL 926 L12
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:113489
Deposited By: George Porter
Deposited On:17 Feb 2022 21:34
Last Modified:17 Feb 2022 21:34

Repository Staff Only: item control page