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 component
stars, which are of spectral type F or G
and lie on or near the main 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 is 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
BACK TO TOP
|