http://technology.sympatico.msn.cbc.ca/News/ContentPosting?newsitemid=corot-planet&feedname=CBC-TECH-SCIENCE-V3&show=False&number=10&showbyline=True&subtitle=&detect=&abc=abc&date=True&pagenumber=1



Newest planetary discovery is small, fast and hot


A European space telescope has found a unique planet 390 light years away with a diameter less than twice that of the Earth, making it the slimmest planet yet detected outside our solar system.


03/02/2009 2:38:30 PM



CBC News

The planet also lies very close to its parent star - about 2.5 million kilometres - and so completes an orbit in a speedy 20 hours. By comparison, the closest planet to our sun, Mercury, orbits at an average distance of 58 million kilometres and completes a circuit of the sun once every 88 days.

European astronomers, who announced the finding Tuesday at a symposium in Paris, also believe the planet may be the fastest yet discovered.

Because of its close proximity to its sun-like star, the planet is also extremely hot, with temperatures estimated at between 1,000 and 1,500 C.

Astronomers found the planet using the COROT space telescope in large part because its close proximity made it easier to detect when it passed in front of - or transited - its star, dimming the star's light.

COROT had to look far away to spot the change: the star the planet orbits lies 3,690 trillion kilometres distant, or about 24.6 million times the average distance from the Earth to the sun.

The density of the planet, named COROT-Exo-7b, is still under investigation, so it is too early yet to say what its mass is relative to the current record-holder for least massive planet: a small planet discovered in 2008 orbiting a spinning neutron star.

Because of its temperature, however, the researchers speculate the newly discovered planet may be rocky like Earth and covered in liquid lava, or it could belong to a class of planets thought to be made of rock and water in equal amounts.

"This discovery is a very important step on the road to understanding the formation and evolution of our planet," Malcolm Fridlund, the European Space Agency's COROT project scientist, said in a statement.

"For the first time, we have unambiguously detected a planet that is 'rocky' in the same sense as our own Earth. We now have to understand this object further to put it into context, and continue our search for smaller, more Earth-like objects with COROT," he said.

The discovery has been submitted for publication in the journal Astronomy and Astrophysics.

COROT-Exo-7b is one of the few terrestrial planets - small rocky planets like the Earth, Mars, Venus and Mercury - discovered outside our solar system.

About 330 planets outside our solar system - called exoplanets - have been discovered thus far. Most of these have been huge gas giants that are easier to detect when they pass in front of a star or through an alternative method called gravitational lensing, whereby the presence of the planet is inferred based on the way a star's light bends in response to the planet's gravitational influence. A select few very large exoplanets have also been seen directly.

COROT, launched in 2006 from the Baikonur Cosmodrome in Kazakhstan, was specifically designed to detect tiny changes in brightness from nearby stars as a result of transiting planets.

NASA's Kepler telescope, set to launch on March 5, is designed to use similar methods of detection, but with a more focused mission - limiting its search to transiting Earth-like planets in habitable zones of space, where the temperatures on the planet might support liquid water and where it might be possible to sustain life.

How is that possible to orbit that close?

You have to remember that the Sun has enough gravatational pull to keep Pluto in its orbit. A planet that close to a star shouldn't be around anymore.

The planet also lies very close to its parent star - about 2.5 million kilometres - and so completes an orbit in a speedy 20 hours.

Just so you know, the proximity of a celestial body to what it's orbiting affects it's average velocity. The distance between two orbiting bodies is inversely (but not linearly) proportional to their relative velocities. In other words: the closer, the faster.

^^

the fact that it is moving at a very high speed balances this out.

Very cool, there could be incredible new materials or strange gases undiscovered on that planet.

I didn't realize speed was a factor.

But the planet has to be scorching hot, double what Venus is probobly. And as the Star expands the planet will be engulfed sooner.

This post was edited by SalvationDG on Feb 6 2009 02:52pm

Yes it is hot

And?

a star actually contracts as it runs out of hydrogen, until the core pressure is hot enough to burn helium then it turns to red giant/super red giant and expands.

the discovery of another new planet is exciting i guess, but if you think about it we will be discovering exponentially more exoplanets every year as our technology improves. sry, i subscribe to astronomy monthly and have read too many boring articles about discovering new exoplanets (which we will never actually know anything about in our lifetime).

i want to know about additional planets in our solar system. yes they most likely exist. it is actually easier to detect exoplanets close to their parent star than remote worlds off past pluto with current technology. put that in your pipe and smoke it.

This post was edited by juliusjuice on Feb 11 2009 01:57pm

I didn't say when it ran out of Hydrogen, I said when it expands, so I knew that.