Rotating Question Curious About Astronomy? Ask an Astronomer

Does the particles involved in a star's final core collapse travel faster than the speed of light?

I've read that the final core collapse of a star happens within less than a second. It seems to me that the outer layers of particles would have to go faster than the speed of light for this to occur so quickly. Is this actually true? Have I misread? Miscalculated? Or else, how can it occur so quickly?

The 'core' of the star is much smaller than the whole star. At the time of the final core collapse of a star, the core itself is only about the size of Earth, and it contracts to something approximately sixteen kilometers across (diameter). So if the star core has a radius of about 6378 kilometers (Earth’s radius) when it begins to collapse, then it has to contract to something with a radius of about 8 kilometers. The outer particles thus have to travel 6370 kilometers in less than one second, but the speed of light is 300,000 kilometers per second, so they actually have plenty of time to collapse.

October 2008, Sarah Scoles (more by Sarah Scoles) (Like this Answer)

Still Curious?

Get More 'Curious?' with Our New PODCAST:

More questions about Stars: Previous | Next

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.

Table 'curious.Referrers' doesn't existTable 'curious.Referrers' doesn't exist

This page has been accessed 6620 times since October 28, 2008.
Last modified: October 7, 2009 2:22:45 PM

Legal questions? See our copyright, disclaimer and privacy policy.
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)