Unusually faint for its spectral type, Groombridge 1830 is a yellow - orange halo subdwarf star of spectral and luminosity type sdG8p / VI. (solstation.com)
In 1998, nine Sol - type stars (naked - eye objects Omicron Aquilae, Kappa Ceti, and Pi1 Ursae Majoris, as well as MQ / 5 Serpentis, UU Coronae Borealis, S Fornacis, MT Tauri, BD +10 2783, and Groombridge 1830 — now believed to be a single, Halo subdwarf without a «flare star» companion) were found to have produced superflares, on average, about once per century. (members.nova.org)
We determine typical colors of M0 - T9 dwarfs, and we highlight the distinctive colors of subdwarfs and young objects. (arxiv.org)