Wondody | The World of Odysseys

🌍 Did you know that more than half of all known stars are part of double or multiple star systems? 

In the celestial panorama, while they appear relatively isolated from one another, stars are not in fact solitary bodies, but come together to form associations and clusters of varying density. In some cases, they form much closer links, forming pairs known as double stars or binary systems, in which the evolution of one star influences that of the other. In the majority of binary systems, the distance between stars remains high. The periods of revolution of one star around the other mostly exceed 100 years.



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💥 Multiple star systems: 
- A star is a gigantic nuclear factory that produces light. The one we know best, and the one closest to us, is the Sun. But there are billions of billions of stars like the Sun in the Universe. They shine like the Sun, but we only see them at night. The Sun, on the other hand, is so close to us that its presence during the day dazzles us and even prevents us from seeing the other stars. Unlike a planet, a star produces its own light. Planets, on the other hand, simply reflect the Sun's light. 

A star is a gigantic ball of gas millions of times more massive than the Earth, and hundreds of times larger. It spins on its axis, producing intense light. Surface temperatures reach several thousand degrees. There is a wide variety of stars, each different from the next: red, blue, massive, small...

Stars emit light because the matter that makes them up is extremely compressed in their center, in what is known as the star's core. The heat in this core reaches several million degrees, producing nuclear reactions and releasing gigantic amounts of energy. This energy is then released in the form of light. Nuclear reactions in the core cause atoms to coalesce and fuse. In the vast majority of stars, the nuclei of hydrogen atoms fuse to form nuclei of helium atoms.

The discovery of double stars was one of the first to be made with telescopes. The star Mizar, located in the Big Dipper, was the first to be identified as such. Scientists immediately surmised that Mizar must not represent a unique case, given the sheer number of stars in the Universe. In the 1780s, a catalog was published reporting the observation of almost 700 double stars.


Double stars are divided into three main categories. There are visual binaries, photometric binaries and spectroscopic binaries. This classification refers to the way in which the stars are associated. 
Visual binaries are so named because of their motion relative to another star, presumed to be its companion. Photometric binaries are those that exhibit periodic variations in brightness due to reciprocal eclipses of one star over the other. They are also known as "eclipsing variables". Spectroscopic binary stars are known thanks to a stellar spectroscopy technique that uses the Doppler effect of spectral lines to check whether two stars at a close distance are related or not.

The binary system KIC 7177553 #astronomy #galaxy #universe