All You Need to Know About Stars

 

We all love gazing into the night sky and enjoy the twinkling of the stars. But, have you ever wondered what they are?

How they are born?? Will they always stay as a twinkling star?? Well, if you are curious to know some amazing facts about them, here we go!!!

Stars are gigantic celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores.

A Star Is Born

- Stars are condensed mass of boiling plasma and hence they are formed from a cloud of hydrogen and helium

- This cloud is known as Stellar Nebulae

- The cloud starts to get condensed because of its own gravitational force which pulls the gases inwards. As a result, the gas lump rotates faster and becomes a nearly round clump of gases known as a protostar

- A protostar transforms into a star when its internal heat and pressure reaches 1 million degrees C and the nuclear fusion makes it a smaller mass with high atomic density.

Do Stars Have a Life Cycle?

Well, yes, Stars that forms from the Stellar Nebulae can be broadly classified into two:

1. Average Star

2. Massive Star

- An average star passes through a phase of Red Giant- Planetary Nebula and becomes a White Dwarf while, a massive star becomes a Red Supergiant- Supernova and either turns into a Neutron Star or a Black Hole

- Small stars, like the Sun, will undergo a relatively peaceful death that sees them pass through a planetary nebula phase to become a white dwarf, which eventually cools down over time and stops glowing to become a so-called "black dwarf"

- Massive stars, on the other hand, will experience a most energetic and violent end, which will see their remains scattered about the cosmos in an enormous explosion, called a supernova

Once the dust clears, the only thing remaining will be a very dense star known as a neutron star, these can often be rapidly spinning and are known as pulsars. If the star which explodes is especially large, it can even form a black hole.

Some Cool Facts About Stars

1. Sun Is the Closest Star to the Earth

-  It is pretty amazing to know that Sun is the closest star to our Earth, located a mere 150 million km away

- Alpha Centauri is the third-brightest star in our night sky – a famous southernstar – and the nearest star system to our sun. Through a small telescope, the single star we see as Alpha Centauri resolves into a double star A and B. This pair is just 4.37 light-years away from us.

- In orbit around them is Proxima Centauri. At a distance of 4.25 light years, Proxima is the closest-known star to our solar system.

2. Red Stars Are the Coolest

- The color of stars can range from red to white to blue. Red is the coolest color; that’s a star with less than 3,500 Kelvin. Stars like our Sun are yellowish white and average around 6,000 Kelvin. The hottest stars are blue, which corresponds to surface temperatures above 12,000 Kelvin

3. The Biggest Known Star

- The largest known star (in terms of mass and brightness) is called the Pistol Star. It is believed to be 100 times as massive as our Sun, and 10,000,000 times as bright! It was discovered in 1990. 

4. When We Look at Stars, We Are Actually Looking Into the Past  

- Stars are light years away from us. A light year is the distance, light travels in one earth year (365 days).

- Its equivalent to 9.46 trillion kilometers

- Sirius, also known as the Dog Star or Sirius A, is the brightest star in Earth's night sky is 8.6 light years away. That means, when you look at Sirius tonight, you see it as it was 8.6 years ago.

Astronomers See First Hint of Silhouette Star Spaghettified by Black Hole

- Stars living in the inner region of their galaxy are in danger of getting torn into slim filaments by the supermassive black hole.

- When a star passes too close to a black hole and the extreme gravitational pull from the black hole shreds the star into thin streams of material — a process called ‘spaghettification’.

- Now a group of astronomers, including lead author Giacomo Cannizzaro and Peter Jonker from SRON/Radboud University, has for the first time observed spectral absorption lines caused by strands of a spaghettified star.

Written By - Abija PB

Edited By - Gunika Manchanda