Life of Stars
Starting off
Did you know that before stars begin to form in a nebula, the clouds of gases and dust swirl around and around? They then form into clumps which grow larger and larger.
Cloud collapse
Eventually, something causes the clouds to collapse. Some astronomers think that this might happen when clouds pass through the arm of a spiral galaxy. (The Milky Way is a spiral galaxy too)While some astronomers suggest that the shock wave from an exploding star (a supernova)might start the collapse. This is how a supernova explosion looks like.
BOOM!
A Shining Star
As the cloud collapses, the temperature rises inside. (It becomes scorching hot) After tens of thousands of years of collapse, a hot core forms. The core gets hotter and hotter until nuclear reactions begin inside, making the clump of gases shine.The new star has been born.YAY! Most new stars are hot and bright while some are cooler and dimmer.
WOW! SHINING STARS........😮🤩
This image,taken by the Hubble Space Telescope shows a nebula in the irregular galaxy NGC 2366.It is 10 million light years away.Wow, that is soo far away.The brightest star visible in this nebula may be 60 times as big as our Sun!
OUR SUN
At first,most new stars burn very brightly.They appear either blue or white.This state continues for millions of years.As they get older,they settle down and shine less brightly but more steadily,like our Sun.And guy do you know that our Sun is only halfway through its lifespan of around 10 billion years.
LIFE OF A STAR (Introduction)
Stars burn with different brightnesses and colours.The hotter the star, the bluer it shines.Of course, their lifespans are different too.The smaller the star,the longer it tends to live.
Lifespans
Stars such as our Sun have a lifespan of about 10,000 million years.Stars smaller than our Sun,called dwarf stars,live longer.Stars larger than our Sun are called giant stars.The biggest of all is called supergiant stars.They have a short lifespan of only a few million years.
Can you guess who is this? Well, this is our Sun! The Sun is a yellow star.Our Sun is smaller than Rigel and Arcturus.Now you may be wondering...is there a star smaller than our Sun?There is,scroll down for the answer!
DEATH OF A STAR
Eventually, a star's supply of gas runs out and it dies.As they die,stars that are the size of our Sun (or smaller) swell up and turn red.Now they are called red giants.
Slowly they puff their outer layers of gas,called planetary nebulae*, into space.
*A planetary nebula has nothing to do with planets.
This is how The Cat's Eye Nebula looks like.The red and green areas are clouds of dense,glowing gas.This nebula is also known as NGC 6543 and Caldwell 6.It is a planetary nebula in the northern constellation of Draco, discovered by William Herschel on February 15, 1786.
WHITE DWARF
A small,almost dead star,called a white dwarf,is left.It is about the size of a planet and is very heavy and dense for its size. Are you guys confused? Okay, let me explain.But we are gonna need some imagination.I want you guys to imagine a golf ball that weighs as much as a truck.Whoa, that is weird...well that resembles the weight of a white dwarf.Because it is so dense,a white dwarf generates huge gravity.It eventually cools and fades.
This is how a white dwarf looks like.
The White Dwarf is so shiny...
EXPLOSIVE DEATH!
Stars that are bigger than our Sun have a really spectacular death.First, they swell into vast red stars called red supergiants.Then they blow up with a huge explosion,called a supernova (the one that we saw earlier)
Four supernovas have been seen in our galaxy in the last thousand years.They glowed brighter than anything else around them for several days before disappearing.
Dense and Heavy
The supernova leaves a rapidly expanding layer of gases and dust with a small spinning star in the middle.This spinning star is a neutron star.It is even denser and heavier than a white dwarf.Are you guys confused? Okay let me explain,but before I start explaining,I just want to tell you guys that you are going to need some imagination to understand what I am saying.Now imagine a golf ball which weighs as much as a skyscraper.Whoa!That is extremely heavy.
Some neutron stars send out beams of radiation that swings around as the star spins.These stars are called pulsars.
THIS IS HOW A NEUTRON STAR LOOKS LIKE.
THIS IS AN IMAGE OF A PULSAR STAR.
BLACK HOLES
Before I begin I want to give you guys a warning.Please don't fall into a black hole while reading this! Well, this won't happen so don't worry.Actually,this time I want to tell you guys a joke before ending off.Here we go!
When the very biggest stars die they form red supergiants.Then they explode into a supernova.However,when they collapse,they shrink so much that they virtually vanish from the universe.They become what we call,black holes -bottomless pits which nothing escapes.
Sucked in
Black holes vary in size from being too small to see to the size of a galaxy.They are so dense and heavy that their gravity sucks everything inside them,even light.
Well,this means that we can't see black holes;but we can detect them by looking for stars and other objects that are being 'eaten'.Anything that gets sucks into a black hole is crushed by its gravity.Scientists think that in the middle of our galaxy lies an enormous black hole,surrounded by old red stars.
THIS IS HOW A REAL BLACK HOLE LOOKS LIKE.
As I promised I am going to end off this blog entry with a few jokes.Ready or not here we laugh!
A black hole walks into a restaurant
A black hole walks into a restaurant and orders a drink.
The waitress asks if it would like food with that.
The black hole says, "No thanks, I'm a light eater."
- Why don't black holes get good grades? They aren't bright enough.
In my next blog I am going to give you guys some information about the galaxy we live in. (Hint of the title)
Sneak peek into next blog........
Well,we have come to the end of this blog entry, but I am going to give you guys a peek into the next blog entry.Let us dive in!!
Compared with other galaxies,our galaxy,is relatively large.It measures approximately 100,000 light-years across, Earth and the rest of our Solar System lie about 28,000 light-years from the middle of our galaxy................Bye for now.Comment below on your thoughts about this blog.And I have added the follow option for you guys.Please follow my blog and receive a notification on the release of my next blog.And don't forget to share! Bye!
