18 December 2009

Astronomers find Super Earth-like planet

A solid planet with potential for water and an atmosphere has been found only 40 light years from the Earth. The planet is approximately 6 times as large as the Earth and orbits a red dwarf star, which is approximately one fifth of the size of the Sun. However, life is unlikely as the temperature on the planet is about 200 degrees. The discovery has just been published in the prestigious journal, Nature. 

A solid planet with potential for water and an atmosphere
has been found only 40 light years from the Earth.
Artists rendering

”When searching for Earth-like planets, it is easier to find them orbiting smaller stars like this one here”, explains the Danish astrophysicist Lars Buchhave.

He is a PhD student at the Niels Bohr Institute and is currently at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, where he is working with the team of researchers who discovered the planet.

Lars Buchhave explains that when the planet passes in front of the lightweight star, there is a bigger dip in brightness and because of the gravity of the planet there is a small wobble in the star, which is easier to measure. 

The hunt for Earth-like planets
The planet was discovered using a series of surveillance telescopes at an observatory in Arizona, which is run by the research group at the Harvard-Smithsonian Centre for Astrophysics. Using a special instrument, HARPS at ESO in Chile, precise velocity measurements of the star were obtained and with these the mass of the planet could be calculated. The planet is the second Super Earth, for which we have calculated both mass and radius and it is the first with an atmosphere. The measurements show that it has a core of rock and iron.

The hunt for Earth-like planets continues and Lars Buchhave and the research team are also looking for planets with NASA’s new satellite Kepler. ”Kepler measures the brightness of stars hundreds of times more accurately than can be done from Earth so we can also find Earth-like planets around stars like the Sun”, explains Lars Buchhave and adds, ”that the hunt for Earth-like planets is now really taking off”.