What is binary star system?
In a binary star system, there are two stars, both orbiting their common bary centre.
The stars in a binary star system are separated by about 10 to 20 a.u.
Do binary stars actually exist?
It is estimated that fifty percent of all stars in the Universe are continued in binary systems.
Why is the study of binary star systems of importance to astronomers?
Applying Kepler’s laws (linking stellar masses with time and distance) to binary systems, the stellar masses of the component stars can be directly calculated. This is of utmost importance to astronomers.
How do astronomers keep track of the orbits of the individual stars in a binary star system?
While observing binary star systems one star is considered stationary and the orbit of the other companion star around it is plotted. From this information the actual paths of both stars can be computed.
What is a tristar system?
A tristar system is a system in which two companion stars (sharing a common orbit) orbit a central star.
Do tristar systems actually exist?
No tristar systems have been detected so far. However, if such tristar systems do exist, then the orbit would have to be large in relation to the diameters of the stars to avoid serious tidal effects and ensure stability of the system.