11 New Extra-Solar Planets Announced

Shooter6947 writes: "The European planet hunting team, including Mayor and Queloz who first found 51 Pegasus b in 1995, have just announced the discovery of 11 new extrasolar planets. The new list includes 2 multiple planet systems, one planet with an orbital eccentricity of .93, and another in a nearly circular orbit near its star's habitable zone. Kickass!"

Comments

Re:Wow... how do they find these things?

[mperrin]

These planets are detected indirectly, by noticing their effects on the stars they orbit. As the planet swings around the star, it makes the star move opposite it (to be precise, both the planet and star are moving around the center of mass of the system.) This stellar motion can be detected via extremely careful measurements of the Doppler shifting of the star's light.

Take a look at Geoff Marcy's website at exoplanets.org. Marcy is a professor here at Berkeley who leads one of the two teams which has done most of the planet finding thus far. This most recent announcement is by Michel Mayor, a Swiss astronomer who leads the other major extrasolar planet hunt. I think the two teams have a fairly friendly rivalry going on, and often both end up observing/discovering the same planets. One of Geoff's graduate students (who I think reads /.; Jason, you reading this?) told me that this latest batch was all discovered by using southern hemisphere telescopes, so none of these were discovered by Marcy et al's search, since that is conducted solely with Northern hemisphere telescopes.

Right now, we're finding Jupiter-sized planets around roughly 5% of the stars we've looked at - 60-ish planets around about a thousand stars. It's expected that the actual numbers of stars with planets is much higher than that, potentially as much as 50% or so, but smaller planets or ones further from their parent star are much harder to detect, so we have not yet identified any.