TYPES OF STAR A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z           HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site W Ursae Majoris star W Ursae Majoris Photo: ESO Online Digitized Sky Survey A type of eclipsing binary with a very short period of a few hours up to a day. In W UMa systems, the components stars, which are of spectral type F or G and lie on or near the mean sequence, form a contact binary and have pulled each other into teardrop shapes. The primary and secondary minima are virtually the same (some 0.6 to 0.8 magnitude deep) and there's a continuous light variation throughout the orbit, with no clear start or end to an eclipse. W Ursae Majoris itself lies 162 light-years away and consists of two stars not unlike the Sun, the primary with a mass of 0.99 Msun, a radius of 1.14 Rsun, and a luminosity of 1.45 Lsun, and the secondary with a mass of 0.62 Msun, a radius of 0.83 Rsun, and a solar-equivalent luminosity. Related entry    • variable stars Related category    • TYPES OF STAR Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP