First temperate exoplanet sized up (w/ Video)

Mar 17, 2010
This artist's impression shows the transiting exoplanet Corot-9b. Discovered by combining observations from the CoRoT satellite and the ESO HARPS instrument, Corot-9b is the first "normal" exoplanet that can be studied in great detail. This planet has the size of Jupiter and an orbit similar to that of Mercury. It orbits a star similar to the sun located 1500 light-years away from Earth towards the constellation of Serpens (the Snake). Corot-9b passes in front of its host star every 95 days, as seen from Earth. This "transit" lasts for about 8 hours. Like our own giant planets, Jupiter and Saturn, the planet is mostly made of hydrogen and helium, and it may contain up to 20 Earth masses of other elements, including water and rock at high temperatures and pressures. Credit: ESO/L. Calçada

(PhysOrg.com) -- Combining observations from the CoRoT satellite and the ESO HARPS instrument, astronomers have discovered the first “normal” exoplanet that can be studied in great detail. Designated Corot-9b, the planet regularly passes in front of a star similar to the Sun located 1500 light-years away from Earth towards the constellation of Serpens (the Snake).

"This is a normal, temperate exoplanet just like dozens we already know, but this is the first whose properties we can study in depth," says Claire Moutou, who is part of the international team of 60 astronomers that made the discovery. "It is bound to become a Rosetta stone in exoplanet research."

"Corot-9b is the first exoplanet that really does resemble planets in our ," adds lead author Hans Deeg. "It has the size of Jupiter and an orbit similar to that of Mercury."

"Like our own giant planets, Jupiter and Saturn, the planet is mostly made of hydrogen and helium," says team member Tristan Guillot, "and it may contain up to 20 Earth masses of other elements, including water and rock at high temperatures and pressures."

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This animation shows an artist’s impression of the transiting exoplanet Corot-9b. The first sequence shows the planet as it orbits its host star, while the second highlights the transit of the planet. Discovered by combining observations from the CoRoT satellite and the ESO HARPS instrument, Corot-9b is the first “normal” exoplanet that can be studied in great detail. This planet has the size of Jupiter and an orbit similar to that of Mercury. It orbits a star similar to the Sun located 1500 light-years away from Earth towards the constellation of Serpens (the Snake). Corot-9b passes in front of its host star every 95 days, as seen from Earth. This “transit” lasts for about 8 hours. Like our own giant planets, Jupiter and Saturn, the planet is mostly made of hydrogen and helium, and it may contain up to 20 Earth masses of other elements, including water and rock at high temperatures and pressures. Credit: ESO/L. Calçada

Corot-9b passes in front of its host star every 95 days, as seen from Earth. This "transit" lasts for about 8 hours, and provides astronomers with much additional information on the planet. This is fortunate as the shares many features with the majority of exoplanets discovered so far.

"Our analysis has provided more information on Corot-9b than for other exoplanets of the same type," says co-author Didier Queloz. "It may open up a new field of research to understand the atmospheres of moderate- and low-temperature , and in particular a completely new window in our understanding of low-temperature chemistry."

More than 400 exoplanets have been discovered so far, 70 of them through the transit method. Corot-9b is special in that its distance from its is about ten times larger than that of any planet previously discovered by this method. And unlike all such exoplanets, the planet has a temperate climate. The temperature of its gaseous surface is expected to be between 160 degrees and minus twenty degrees Celsius, with minimal variations between day and night. The exact value depends on the possible presence of a layer of highly reflective clouds.

The CoRoT satellite, operated by the French space agency CNES, identified the planet after 145 days of observations during the summer of 2008. Observations with the very successful ESO exoplanet hunter — the HARPS instrument attached to the 3.6-metre ESO telescope at La Silla in Chile — allowed the astronomers to measure its mass, confirming that Corot-9b is indeed an , with a mass about 80% the mass of .

This finding is being published in this week's edition of the journal Nature.

Explore further: The hot blue stars of Messier 47

More information: This research was presented in a paper published this week in Nature ("A transiting giant planet with a temperature between 250 K and 430 K"), by H. J. Deeg et al. (doi: 10.1038/nature08856)

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User comments : 8

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Husky
not rated yet Mar 17, 2010
you'd expect a jupiter sized planet to have a bunch of moons asome of them might be goldilocks
Shootist
1 / 5 (6) Mar 17, 2010
It orbits a star "similar to the sun" at Mercury distances (95 vs 88 day "year"), yet it's sorta surface temperature is 160C?

For the love of God, man, How?
zbarlici
not rated yet Mar 17, 2010
amazing.. and to think that three generations later we`ll still be just staring at the planet from afar :(
ubavontuba
1 / 5 (5) Mar 17, 2010
I wonder if a system like this could support other planets in the habitable zone. I'm thinking the effects of the binary mass might disturb their orbits.
El_Nose
not rated yet Mar 18, 2010
could someone answer this---

does NASA exclude looking at really large stars for planets??

my reasoning is that for a planet to be in the habitable zone or sweet spot on a bigger star (say 5-8 solar masses ) they would have to farther out than Uranus (no pun intended) - jupiter takes 11 yrs to orbit and Uranus takes 84 years

On stars bigger than 2 solar masses it is pointless to look for planets with life because they will not pass in front of their star with enough frequency. -- these planets such as this one with a orbit of 95 days is WAY to close to its sun be habitable
Pacalb
not rated yet Mar 18, 2010
amazing.. and to think that three generations later we`ll still be just staring at the planet from afar :(


We don't know that for fact, I mean who's to say what may come along in breakthroughs be that physics or technologies?
Noodle_Naut
1 / 5 (4) Mar 20, 2010
El_Nose, The reason we are not looking that far away is that we can't "see" there. Planet detection is from wobbles in the star. And as a distant planet--star gravitational relationship is weaker, there is far less wobble...beyond the resolution of the technique. The are doubtless many terrestrial planets in the systems that we have detected gas giants. Ween we get some large segmented adaptive optics optical telescopes 300m and larger we can resolve them visually.
Quantum_Conundrum
1 / 5 (2) Mar 21, 2010
It orbits a star "similar to the sun" at Mercury distances (95 vs 88 day "year"), yet it's sorta surface temperature is 160C?

For the love of God, man, How?


Doesn't add up does it? Never does really with astronomy. At that distance, it should be something like 400degrees or more.

Also, not a chance on any "goldilocks" moons. They too would be several times boiling temperature.

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