Atmosphere of an Extrasolar Planet Measured

FORT DAVIS, Texas — University of Texas at Austin astronomer and Hubble Fellow Seth Redfield has used the Hobby-Eberly Telescope (HET) at McDonald Observatory to make the first ground-based detection of the atmosphere of a planet outside our solar system. This research has been accepted for publication in an upcoming issue of Astrophysical Journal Letters.

“It’s a remarkable pioneering discovery,” said McDonald Observatory Director David L. Lambert.

The work is an incremental step in finding life in the universe, falling between the initial detections of planets around other stars (known as “extra-solar planets” or “exoplanets”), and the anticipated discovery of planets similar to Earth.

“What we all want to find is a planet with an Earth-like atmosphere,” Redfield said.

The planet Redfield studied orbits HD189733, a star about 63 light-years away in the constellation Vulpecula, the little fox. But it’s not like Earth. The planet is 20 percent more massive than Jupiter, and orbits very close to its parent star (more than 10 times closer than Mercury is to our Sun).

From Earth’s line of sight, the planet passes directly in front of the star on each orbit. That means this planet, HD189733b, is what’s known as a “transiting extra-solar planet.” It was this “transit” property that allowed the planet’s discovery in 2004 by Francois Bouchy of France’s Laboratoire d’Astrophysique de Marseille, and the detection of its atmosphere in 2007 by Redfield.

Read complete article

[edit on 7-12-2007 by Enceladus]

good news first ground based detection. well done

now we just have to wait and see how the new occulters will perform on ground based telescopes.

Great work by this astronomer, and a lot of work too. It must really be tedious. I'm impressed that it could be done at all from a ground based unit.

Hopefully space telescopes will get in on the act in the future. Imagine what it would meaan to know that an earth like planet with a breathable atmosphere was out there, even if light years away.