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Unformatted text preview: Direct Imaging and Spectroscopy
But…..planets are small dim things close to very large, very bright things.
You need a very large telescope to resolve something that small and that far away.
Then you need to get rid of the light from the star. An interferometer can do this too if the signals from
some of the telescopes are delayed slightly
Darwin (ESA): six space telescopes, each of which will be at least 1.5 meters in diameter. Combines to
form a telescope with the resolving power of a 30 meter telescope.
Terrestrial Planet Finder (NASA)
Planets are close to their stars
Many more highly eccentric orbits than in our Solar System
this is probably detection bias
Implications for the Nebular Theory
Extrasolar systems have Jovian planets orbiting close to their stars.
Theory predicts Jovian planets form in cold, outer regions.
Many extrasolar planets have highly eccentric orbits.
Theory predicts planets should have nearly circular orbits.
Is the nebular theory wrong?
Probably not, but……...
Lots of evidence that planetary orbits migrate! Doppler technique biased towards finding close Jovian planets
Are they the exception or the rule?
Migrating Jovians could prevent terrestrials from forming (or would they…..?)
Is our Solar System rare? ...
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- Spring '08