W Ursae Majoris stars
W Ursae Majoris stars (or W UMa stars for short) are a type of eclipsing binary star system where the two stars are in physical contact. Each star has its own independent core where fusion reactions take place, however they share one common photosphere. The shape of the combined system is determined by the combined effects of gravity and centrifugal force, leading to a double-lobed shape, as shown in the depictions shown above of (from top to bottom) Epsilon Coronae Australis, 44i Boötis and RW Doradus.
This add-on implements 43 W UMa stars which have Hipparcos catalogue numbers. The add-on also contains the Perl scripts used to generate the model files and star catalogue files for Celestia. The add-on is designed to work in Celestia 1.5.1 and later.
The data used to model the stars was taken from the Catalog of Field W UMa systems, available on Carla Maceroni’s webpage. The stellar coordinates were taken from Celestia’s star data files, which are based on ESA’s Hipparcos catalogue. SIMBAD was used to convert from the variable star designations to Hipparcos catalogue numbers.