Facts about space and stars

 Hey every body welcome to my blog post first of all, the moment you open this post pat on  your shoulder and take a deep breath with proud because  you made an attempt to learn something new, at least you are willing to try something new.And the topic is,

        Facts about space and stars

 THE BIG BANG:

About 14 billion years ago the universe materialized out of nothing for unknown reasons.Infinitely smaller than an atom to begin with, the universe expanded to a trillion kilometers across in under a second -an event called the big bang.

At 300 million years, stars appear. stars from when great clouds of gas are pulled into  tight knots by gravity. The pressure and heat become so intense in dense pockets of gas that nuclear reactions begin, igniting the star.

At 500 million years, the first galaxies are forming. Galaxies are enormous clouds of stars held together by gravity.

GALAXIES:

Our sun belongs to  a giant  whirlpool of stars called the milk way. Huge collections of stars called the milky way.Huge collections of stars are called galaxies the milky way is unimaginably vast.

Galaxies come in many shapes and sizes. some are spirals like our own galaxy but others are fuzzy balls or shape less clouds. the smallest have just a few million stars .The largest contain trillion.

Although galaxies look packed with stars ,galaxies are mostly empty space. The stars in galaxy are held together by gravity and travel slowly around the galactic heart.

STAR BIRTH:

Stars have been forming throughout the universe for most of its life. they take shape in vast clouds where thousands of stars are born at a time.

The clouds that give birth to the stars are cold and dense and consists mainly of hydrogen gas . The newly formed stars are huge spinning globes of hot glowing gas mainly hydrogen with helium and small amounts of other elements.Much of this material is packed tightly into the stars cores and it is here that nuclear reactions release energy in the form of heat and light.   

 

HOW NEW STARS FORM:

The star forming process begins when the cloud becomes unstable and breaks up into fragments. Gravity pulls the material in a fragment into an tighter clump and the clump slowly forms a sphere as it shrinks. Now a protostar, this star to be carries on shrinking, its core getting getting denser and hotter. Eventually the and temperature are so high that nuclear reactions begin and the star starts to shine.

Types of stars:

A star begins to shine when nuclear reactions in its core convert hydrogen into helium and release energy. it is then called a "main sequence star". Not all main sequence stars are same they differ in size ,temperature, colour, brightness and the amount of matter they contain. When stars begin to run out of fuel and near the end of their lives, they stop being main sequence stars and may swell up and turn into red giants or shrink to become white dwarfs.

Classifying stars:

The Hertzsprung- Russel diagram is a famous graph that astronomers use to classify stars.The graphs plots brightness against temperature and revels that there are distinct groupings of stars, such as red giants (dying stars) and main sequence stars (ordinary stars) .Astronomers also classify stars by colour, which is linked to their temperature: hot stars are blue ;cooler stars are orange or red.

Star nebulas:

 Clouds of gas and dust in space are called nebulas.Much of the gas and dust in a nebula is debris from old stars that exploded when they ran out of fuel.Over millions of years this material is recycled to make new stars. star birth nebulas are among the most beautiful objects in space their colourful clouds illuminated from within by blue light of newborn stars.

Star clusters:

Stars are not formed singly-they are born in clusters from the same cloud of material at roughly the same time.Eventually, the stars of a cluster  will drift apart and exist alone in space or with a close companion or two.Our sun,like about half of the stars nearest to us, alone. about a third of the stars in the night sky are in pairs bound together by gravity.

Star death:

All stars eventually run out of fuel and die. Most fade away quietly but the most massive stars self destruct in huge explosion that can out shine an entire galaxy.

Finally this is all about stars and star birth catch you all back in my next blog

                                                

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