You are here


January 31, 2010

Stars are huge and heavy. Their gravity holds planets and other smaller bodies in orbit around them, and can influence the environments of other stars that are close by.

For all their heft, though, stars are easily distorted. That's because they're big balls of gas, so it doesn't take a lot to push or pull them out of shape. The Sun, for example, is thicker through the equator than through the poles because its rotation pushes its gas outward.

The two stars that make up the system known as Menkalinan are even more distorted -- they're shaped like eggs.

Menkalinan is part of Auriga, the charioteer. The constellation is best known for its brightest star, Capella. The bright yellow star soars directly overhead this evening, with Menkalinan following behind it.

Both of the stars in the system are bigger, brighter, heavier, and hotter than the Sun. And they're only a few million miles apart -- just a few percent of the distance from Earth to the Sun.

At such close range, the enormous gravity of each star exerts a strong tug on its companion. This tug causes each star to bulge out toward the other. So viewed in profile, Menkalinan would look like a pair of eggs with the small ends pointing toward each other.

Eventually, the two stars will puff up and begin to lose their outer layers. The two stars may trade gas back and forth between them, affecting the ultimate fate of each of them in ways that no one can predict.

Script by Damond Benningfield, Copyright 2009

Get Premium Audio

Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.