Binary Star

Star gazing in night sky can be very soothing when we are unaware of the complexities and real physics acting behind them. But there is always a curiosity among all the people irrespective of age to know the theories working behind the celestial objects which are several light years away. Astronomers use the orientations and behaviors of a special system of stars to understand the fundamental properties of single stars and to understand the formation of astronomical objects! This special system of stars is the binary star or a double star system.

What is binary star?

A pair of orbiting stars that shares a common centre of massis called a double star system, also known as binary star system. Almost 60-70% of all the stars in milky way galaxy are binary stars or a multi star system, i.e. , triple or quadruple star systems. Binary stars are useful in calculating the mass of single stars involved in the system as well as other fundamental properties of similar single stars. There are some subcategories of binary stars based on their visual properties. Some are :

1) Visual binary star system:

With an astronomical telescope having precise resolving power,the stars of the system can be individually resolved. The stars are several astronomical units apart from each other in the system.

2) Eclipsing binary star system:

The orbit plane of the stars is positioned in the line if sight of the observer. They appear as a single point of light to an observer.

3) Spectroscopic binary star system:

The components are either very close to each to other or are very far away. Their orbital motion are detected through their spectral lines. These kind of binary system of stars can’t be resolved through a telescope.

4) Astromeric binary star system:

Binary star system where only one star can be seen at a time, while the other’s position is inferred by the detectable wobble of the first star. This is due to the gravitational pull of smaller star over the larger one!