Hot Jovians
On Nature this morning, and widely re-reported across the wires: two research groups have managed to use the Spitzer directly to detect infrared from hot Jovians orbiting other stars. See Light from alien planets confirmed, reporting on results from Deming et al at the Goddard, and from Charbonneau et al at the Harvard-Smithsonian.
The technique: look for the rise and fall in the total IR coming from the system, due to the planet's orbit taking it alternately in front of and behind the primary. Then subtract the constant starlight. What's left is what's coming from the planet.
It only works (as yet) for hot Jovians—big gas giants close to their primary—but it's still a good trick. And the article goes on to report that the same essential technique can be used for smaller, terrestrial worlds in larger orbits—given dedicated instruments that can take the time to collect data over the longer orbital period.
Reading this stuff, I'm always struck by the way electromagnetic radiation ties our universe together. Just think: the infrared from those bodies, it's been raining down on the top of our atmosphere for untold aeons, just waiting to be detected. And the odd photon (not many, it's true, given the fact that these bodies are none too hot, and given the way long wavelengths and our atmosphere interact) from a distant, Earthlike world has probably bumped into the top of your very head, now and then.
The technique: look for the rise and fall in the total IR coming from the system, due to the planet's orbit taking it alternately in front of and behind the primary. Then subtract the constant starlight. What's left is what's coming from the planet.
It only works (as yet) for hot Jovians—big gas giants close to their primary—but it's still a good trick. And the article goes on to report that the same essential technique can be used for smaller, terrestrial worlds in larger orbits—given dedicated instruments that can take the time to collect data over the longer orbital period.
Reading this stuff, I'm always struck by the way electromagnetic radiation ties our universe together. Just think: the infrared from those bodies, it's been raining down on the top of our atmosphere for untold aeons, just waiting to be detected. And the odd photon (not many, it's true, given the fact that these bodies are none too hot, and given the way long wavelengths and our atmosphere interact) from a distant, Earthlike world has probably bumped into the top of your very head, now and then.
posted by AJM at 9:54 a.m. (Permanent Link)
