Where are stars born?
What is a massive cloud, believed to be the birthplace of the new stars?
Our galaxy, along with many others, contains many large clouds of gas and dust, mostly made up of hydrogen. These clouds are called "nebulae." If the cloud becomes large enough, then its own gravity begins to overcome the gas pressure, and the cloud can begin to collapse. As the cloud collapses, gravity, temperature, and pressure increase, until the cloud has collapsed enough to raise the temperature to that required to fuse (burn) the hydrogen. Once that fusion begins, the energy released halts the contraction, and the outer layers of gas are blown away. What's left is an incandescent ball of mostly hydrogen, set aglow by the fusion reactions in its core: a star.
Get More 'Curious?' with Our New PODCAST:
- Podcast? Subscribe? Tell me about the Ask an Astronomer Podcast
- Subscribe to our Podcast | Listen to our current Episode
- Cool! But I can't now. Send me a quick reminder now for later.
How to ask a question:
If you have a follow-up question concerning the above subject, submit it here. If you have a question about another area of astronomy, find the topic you're interested in from the archive on our site menu, or go here for help.
This page has been accessed 52246 times since September 21, 2002.
Last modified: December 12, 2002 3:19:53 PM
Ask an Astronomer is hosted by the Astronomy Department at Cornell University and is produced with PHP and MySQL.
Warning: Your browser is misbehaving! This page might look ugly. (Details)