Author Topic: First Spectra of Extrasolar Planets  (Read 799 times)

Offline HD209458

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First Spectra of Extrasolar Planets
« on: 02/21/2007 03:26 PM »
Were reported today at a Spitzer briefing. Thought people here might find this interesting; the actual articles are at:

http://arxiv.org/abs/astro-ph/0702507
http://xxx.lanl.gov/abs/astro-ph/0702494

The two teams were able to take infrared spectra of the planets orbiting HD 209458 and HD 189733, both of which are Hot Jupiters with orbital periods of under 5 days. The one around HD 209548 showed two strong emission lines, one around 10 microns that the authors attribute to high-altitude clouds of silicate, and another at about 8 microns that has no obvious explanation. Interestingly, the expected water absorption features don't seem to be there, which means that HD 209458b is a lot "drier" than was thought, and will probably cause a whole raft of extrasolar planetary models to be thrown out.

HD 189733b shows no spectral features whatsoever; which is also puzzling, and also contradicts what theories we have.

Excitingly, the authors of the HD 189733 paper point out that if and when the James Webb Space Telescope is launched, it will be able to do these same kind of measurements on Hot Earths; should they be found.

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