New Cold Subdwarf Discoveries from Backyard Worlds and a Metallicity Classification System for T Subdwarfs

We report the results of a spectroscopic survey of candidate T subdwarfs identified by the Backyard Worlds: Planet 9 program. Near-infrared spectra of 31 sources with red J  − W2 colors and large J -band reduced proper motions show varying signatures of subsolar metallicity, including strong collisi...

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Bibliographic Details

Published in:	The Astrophysical Journal
Main Authors:	Adam J. Burgasser, Adam C. Schneider, Aaron M. Meisner, Dan Caselden, Chih-Chun Hsu, Roman Gerasimov, Christian Aganze, Emma Softich, Preethi Karpoor, Christopher A. Theissen, Hunter Brooks, Thomas P. Bickle, Jonathan Gagné, Ètienne Artigau, Michaël Marsset, Austin Rothermich, Jacqueline K. Faherty, J. Davy Kirkpatrick, Marc J. Kuchner, Nikolaj Stevnbak Andersen, Paul Beaulieu, Guillaume Colin, Jean Marc Gantier, Leopold Gramaize, Les Hamlet, Ken Hinckley, Martin Kabatnik, Frank Kiwy, David W. Martin, Diego H. Massat, William Pendrill, Arttu Sainio, Jörg Schümann, Melina Thévenot, Jim Walla, Zbigniew Wędracki, The Backyard Worlds: Planet 9 Collaboration
Format:	Article
Language:	English
Published:	IOP Publishing 2025-01-01
Subjects:	Brown dwarfs L dwarfs L subdwarfs T subdwarfs T dwarfs Stellar classification
Online Access:	https://doi.org/10.3847/1538-4357/adb39f