


Wednesday, January 25

New extrasolar planet discovered !

Today is a classic example of the difficulties with the email newsletter. I get up at 6am to prepare the newsletter, send it out before going to work and then get home to discover an new extrasolar planet has been discovered and it's all over the news ;-)

Anyway, in case you haven't heard the news. Astronomers have announced the discovery of a new extrasolar planet. This one is unusual in that it's the smallest yet discovered with a mass of only 5 times that of the Earth. This is thought to be a 'rocky' Earth-type planet, and is the next step on the way to discovering other 'Earths' in our galaxy.

For full details see the press release at European Southern Observatory. There's also an artist's impression of the new planet there. (it's almost as if they've been preparing for this announcement !).

The other special thing about this planet it the way it was discovered. Extrasolar planets have usually been discovered by detecting the 'wobble' they cause in the motion of the star they orbit. In this case the planet was discovered by gravitational lensing. This effect, predicted by Einstein, is where light from a star is bent and focused by the gravity of another body (in this case the planet). This leads to an increase in the light from the star when the planet is in a certain position.

More details at our January meeting. That's this coming Tuesday in case you forgot.

See CAS Weblinks for more extrasolar planet related links.

1 comment:

  1. A bit more research on this topic has clarified the method of discovery. The gravitational lensing effect actually focuses the light from a star much further away from the one with the newly discovered planet.

    The star with the planet is a Red Dwarf some 25,000 light years away, so probably the star iteself isn't even visible in the most powerful telescopes.

    More on Tuesday.