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This content will become publicly available on January 29, 2026

Title: New Ultracool Companions to Nearby White Dwarfs
Abstract We conducted a search for new ultracool companions to nearby white dwarfs using multiple methods, including the analysis of colors and examination of images in both the optical and the infrared. Through this process, we identified 51 previously unrecognized systems with candidate ultracool companions. 31 of these systems are resolved in at least one catalog, and all but six are confirmed as comoving companions via common proper motion and consistent parallax measurements (when available). We have followed up four comoving companions with near-infrared spectroscopy and confirm their ultracool nature. The remaining twenty candidates are unresolved, but show clear signs of infrared excess which is most likely due to the presence of a cold, low-mass companion or a dusty circumstellar disk. Three of these unresolved systems have existing optical spectra that clearly show the presence of a cool stellar companion to the white dwarf primary via spectral decomposition. These new discoveries, along with our age estimates for the primary white dwarfs, will serve as valuable benchmark systems for future characterization of ultracool dwarfs.  more » « less
Award ID(s):
2238468
PAR ID:
10571634
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
AAS Journals
Date Published:
Journal Name:
The Astronomical Journal
Volume:
169
Issue:
2
ISSN:
0004-6256
Page Range / eLocation ID:
100
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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