2026/07/28 by Daniel Majaess, Dante Minniti, Matias Gomez +2
Physics and Astronomy · #astro-ph.GA #astro-ph.SR
To appear in publication
arxiv created 2026/07/28 · arxiv updated 2026/07/30
Ultracool and brown dwarf candidates (d\odot\lesssim 125 pc, |b|>8∘) were identified via multiband and astrometric data from CatWISE (W1W2), 2MASS (JHKs), and Gaia DR3 (G, GRP, π, μα, μδ). N≈ 11.8 × 103 candidates emerged once simultaneously constrained by color and absolute magnitude criteria (e.g., G-W2 ≥ 1.75(G-J)-2.25), whereby ≃ 350 sources are absent from the Gaia Ultracool Dwarf (UCD) catalog. Spectral types were approximated using a hybrid MG-MW1 sigmoid that offers additional temperature coverage in certain cases. Subsequent efforts may focus on extending sampling to the deeper NIR VVVX footprint that partly encompasses the Galactic plane, and over the long-term spectroscopically (in)validating candidates missing from the Gaia UCD database.