Star Probes
Orion, the hunter, is disappearing from the evening sky. For a last glance, look low in the west about an hour after sunset. Orion's Belt -- a short line of three stars -- is almost parallel to the horizon. Bright orange Betelgeuse is above it, with blue-white Rigel below.
Both of these stars will end their lives with powerful explosions. Each blast will leave behind only a tiny, superdense core known as a neutron star.
But scientists don't know much about the interiors of these dead stars. They can't see into them, and they can't simulate the interior of a neutron star in the laboratory. But they may soon learn more about these stars by measuring their gravitational waves.
As a neutron star spins, any "bumps" on its surface produce gravitational waves -- "ripples" in space-time. The waves are so tiny that they haven't been detected.
But the waves from some neutron stars may be much bigger than normal. If so, then a new gravitational-wave observatory just might see them.
The interiors of these stars might be made not of neutrons -- one of the particles that makes up the nucleus of an atom -- but of even smaller particles, called quarks. The surfaces of these stars could have bumps a few feet tall. That's not much, but it would allow them to produce much stronger gravitational waves. So the waves could help astronomers learn what conditions are like inside these "dead" stars.
Script by Damond Benningfield, Copyright 2006
For more skywatching tips, astronomy news, and much more, read StarDate magazine.
|
Contact | About | Friends of McDonald | Sign up for Sky Tips
