If you ever want to see the birth of a star, you are not in luck because it takes “just” millions of years for them to form.
A star is born when a big expansion of gas and dust, known as a “dark cloud,” starts to compress and heat up. The compression causes the middle to become so thick and hot that it concentrates making the layers around it disappear.
The rest of the cloud contracts even more, triggering the nuclear fusion reactions that cause a new star to form in the night.
One of the best places for a star to be born in the night sky is the Orion Nebula. The Orion Nebula is 1,500 light years away, which is the same as trillions of miles away from the Earth. You can see the Orion Nebula without a telescope on a clear night as a dim patch of light in the shape of a “sword,” which is located below the three stars of the “belt” in the constellation of Orion the Hunter from Greek mythology.
The light in the Orion Nebula comes from a slim number of hot, luminous stars that have formed over the last few millions of years, and also from other stars being born nearby. But if the theorists are correct, this is just the start. Actually, the Orion Nebula is a small piece of something known as a “giant molecular cloud.” It spans 100 light years and has a lot of dark clouds and territories of star formation.
Some of the stars that we see in the Nebula will die quickly because some of those stars are too hot and bright. They will burst into brilliant “supernovae.”
The next time that the Orion Nebula, the most unique constellation in the sky, will change will be in about a million years. So, the people living in a million years will be able to see the changes.
[Source: AB secrets of the universe]