13-letter words containing b, y, r, u
- visual binary — a binary star having components that are sufficiently separated to be resolved by a telescope.
- vitreous body — a transparent gelatinous substance, permeated by fine fibrils, that fills the interior of the eyeball between the lens and the retina
- vulnerability — capable of or susceptible to being wounded or hurt, as by a weapon: a vulnerable part of the body.
- x-ray burster — a celestial source from which bursts of x-rays are received.
- yekaterinburg — Ekaterinburg.