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Hunting Planets III

StarDate: 
August 28, 2015

It’s been only a couple of decades since astronomers discovered the first planets in other star systems. Yet they’re starting to figure out not just what some of those systems look like today, but what they might have looked like in the distant past.

Astronomers are using the Harlan J. Smith Telescope at McDonald Observatory to hunt for exoplanetsAstronomers are using the Harlan J. Smith Telescope at McDonald Observatory to hunt for exoplanetsOne of the keys is a class of planets known as “cold Jupiters.” They’re roughly the same size and mass as Jupiter, the giant of our solar system, and about the same distance from their parent star.

Many of the planets discovered so far are hot or warm Jupiters. Such a planet is a giant, like Jupiter, but it’s quite close to its star.

The problem, though, is that there doesn’t seem to be any way for such a planet to form so close in — the star would destroy the ingredients that make up such a bulky world.

Instead, such a world probably formed much farther out, as Jupiter itself did. But interactions with the disk of material around the star, as well as other effects, pushed the planet closer in. That may have had disastrous consequences for smaller planets that were born closer to the star — they may have been pushed into the star.

To better understand that process, astronomers at McDonald Observatory are looking for cold Jupiters — giants that stayed close to where they were born. How frequently such planets occur will tell us how likely it is that worlds like Earth survive the process — worlds that are the most likely homes for life.

More about the search tomorrow.


Script by Damond Benningfield, Copyright 2015

 

Today's program was made possible in part by a grant from the National Science Foundation.

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