[X] My Assistant

[karolp]

And by serious I mean those with multiple planets, relatively nearby (within 100 or 50 lyrs) and... potentially harbouring some Earth analogues as well. With about 200 extrasolar planetary systems, we are finally nearing some profound conclusions on how planets around other Suns might be arranged and where other Earths would fit in there. I'd love to see some coverage and discussion on those here. All in all, we might exercise such babies like COROT and Kepler on them within a few years.

To start with, consider those two:

55 Cancri - or "the one with 4 planets, including a jupiter at 5 AU and possibly an earth at 1 AU



and

HD 69830 - or "the one with 3 neptunes, an asteroid belt and an earth - maybe..."



As for 55Cnc, there is some disagreement whether the parent star is slightly more or slightly less massive than the Sun. Please compare those sources for that:

Exoplanets.org

Planet Quest

The Extrasolar Planets Encyclopedia

The way those systems are gradually discovered is like focusing an image in an eyepiece. They gradually arrive at more accurate values for the number and orbits of planets by examining wobles (observed as Doppler shifts) of the parent star measured over ever longer periods of time. You can actually hear Geoff Marcy as he is sitting in the control room of Keck and gives directions to the guy operatng the scope (just go to the 12th minute of that program):

(May 2004) - Geoff Marcy discovering exoplanets live ;-)

You can also here some news directly from him here:

(September 2004) - More of Geoff Marcy

And do not forget Chris Lovis:

...also known as "the French guy who discovered those 3 neptunes"

[Jyril]

It would be weird if hot Jupiters are not tidally locked.

The Upsilon Andromedae b detection is interesting since some suggested that such configuration could not be stable (as opposed to a giant equatorial band and much more even temperatures).