David Kirkpatrick

February 15, 2008

Major astronomy discovery — a twin for Jupiter

Filed under: Science — Tags: , , , — David Kirkpatrick @ 10:19 pm

This is very cool. We’ve found a gas giant planet the same size as Jupiter, and orbiting a similar sized star to our sun at roughly the same distance, a mere 60 light years away.

From Phil Plait’s Bad Astronomy explaining just how important this discovery really is:

Finding a planet like this isn’t as easy as it sounds! Finding planets with the same mass as Jupiter isn’t hard; many have been found with even lower mass. The hard part is finding one that is orbiting a sun-like star at the same distance Jupiter orbits our Sun. The closer in a planet is to its star, the easier it is to find: the method used measures how hard the planet’s gravity tugs on its parent star as it orbits; the planet pulls the star around just like the star pulls the planet, and we see this as a change in the velocity of the star toward and away from us (called the radial velocity; Wikipedia has a nice animated GIF for this), and that effect gets bigger with bigger planets, and the closer they orbit.