Suberb star

Do you know about STARS..? 

Let's know some details about stars.....

STARS

Stars are the most well-known astronomical objects, and they are the primary building blocks of galaxies. The age, distribution, and composition of stars in a galaxy reveal information about the galaxy's history, dynamics, and development. 

Furthermore, stars are responsible for the production and dispersion of heavy elements such as carbon, nitrogen, and oxygen, and their properties are inextricably linked to the properties of the planetary systems that may form around them. As a result, the study of star birth, life, and death is essential to the field of astronomy.

Formation of the Star

Stars are born within dust clouds and are dispersed throughout most galaxies. The Orion Nebula is a well-known example of a dust cloud. Deep within these clouds, turbulence creates knots with enough mass that the gas and dust begin to collapse under their own gravitational attraction. The material at the centre of the cloud begins to heat up as it compresses. 

This heated core in the centre of the collapsing cloud is known as a protostar, and it will one day become a star. Three-dimensional computer models of star formation predict that spinning clouds of collapsing gas and dust may split into two or three blobs, explaining why the majority of stars in the Milky Way are two or three blobs.

As the cloud disintegrates, a dense, heated the centre emerges and begins to collect dust and gas. Not all of this material becomes a star; the remaining dust may form planets, asteroids, or comets, or it may remain as dust. The cloud may not collapse at a constant rate in some circumstances. In January 2004, an amateur astronomer entitled James McNeil spotted a tiny nebula near the nebula Messier 78 in the constellation Orion. When observers from all across the world focused their telescopes at McNeil's Nebula, they discovered something unusual: its brightness appeared to change. NASA's Chandra X-ray Observatory observations revealed a possible explanation: The interaction between the magnetic field for the newborn star and the surrounding gas generates episodic increases in brightness.

From the beginning of the collapse until adulthood, a star the size of our Sun takes around 50 million years. For around 10 billion years, our Sun will remain in this mature phase (on the main sequence as indicated in the Hertzsprung-Russell Diagram). Stars are powered by nuclear fusion of hydrogen to generate helium deep into their cores. The outflow of energy from the star's centre regions supplies both the pressure required to keep the star from collapsing under its own weight and the energy that allows it to shine. Main Sequence stars have a wide range of luminosities and colours, as illustrated in the Hertzsprung-Russell Diagram, and can be classed based on those features.

The most massive stars, known as hypergiants, on the other hand, may be 100 or more times more massive than the Sun and have surface temperatures of more than 30,000 K. Hypergiants emit hundreds of thousands of times more energy than the Sun but have a few million-year lifetime. Although extreme stars like these are thought to have been widespread in the early Universe, they are now incredibly rare - the Milky Way galaxy has only a few hypergiants.

Fate of the Star

The larger  star, in general, the shorter its life, yet all except the most massive stars live for billions of years. Nuclear reactions stop after a star has fused all of the hydrogen in its core. When the core is deprived of the energy required to sustain it, it begins to collapse in on itself and gets much hotter. Because hydrogen is still available beyond the core, hydrogen fusion continues in a shell around it. The expanding hot core pushes the star's outer layers outward, forcing them to expand and cool, changing the star into a red giant.

If the star is huge enough, the collapsing core could get hot enough to support more exotic nuclear reactions that consume helium.

The formation of a galaxy begins with the gathering of hydrogen gas in the form of a very big cloud known as a nebula. Growing nebulas eventually form isolated clusters of gas. These aggregates continue to develop into denser gaseous masses, allowing stars to form.

When really huge stars originate, a great mystery emerges. Astronomers have discovered that stars up to six times the mass of our Sun are created in the manner described in this article. Larger stars necessitate a different procedure because the pressure from the stars' radiation pushes the disc away, preventing stars from becoming larger than around six times the size of our Sun.

Astronomers have observed these massive stars, proving that large stars exist and must be born in some way. However, how they are born remains a mystery to astronomers all around the world.

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By kavitha.. 😇