... Star Atlas . ... Astronomy for Kids . ... Vast halo boosts Andromeda's size . ... These stars probably represent Andromeda's stellar halo, a distinct structural component of the galaxy that has eluded astronomers for over 20 years, Guhathakurta said. Following up on their discovery of Andromeda's halo, the researchers have found evidence that stars in the halo are chemically anemic compared with stars in the inner parts of the galaxy, said Jasonjot Kalirai, a postdoctoral fellow at UCSC. ...