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Discovery of a Tatooine planet

A photo taken at the European Southern Observatory (ESO) reveals a mass orbiting a young binary star that may just be a planet.

Michelle Starr Science editor
Michelle Starr is CNET's science editor, and she hopes to get you as enthralled with the wonders of the universe as she is. When she's not daydreaming about flying through space, she's daydreaming about bats.
Michelle Starr
2 min read

The position of the planet in 2012. The green arrow shows its position in 2002, and the blue circle where the object would have been expected to be found were it just a background object.
(Credit: ESO)

A photo taken at the European Southern Observatory (ESO) reveals a mass orbiting a young binary star that may just be a planet.

If it is, it'll be a coup — the first direct image of a planet with two suns, dubbed "Tatooines" after Luke Skywalker's home planet in Star Wars.

Taken in November last year by the Very Large Telescope at ESO-Paranal in Chile, the image shows a large object, dubbed 2MASS J01033563-5515561ABb (2M0103 for short), close to a binary M-class system. A search through the telescope's archives revealed that the object had also been captured in 2002, allowing the scientists — led by Philippe Delorme of the Joseph Fourier University in Grenoble, France — to track and confirm its orbit.

The object is big, at 12 to 14 times the mass of Jupiter, which means it may not be a planet at all, but rather a type of star known as a "brown dwarf" — that is, a star too small to sustain hydrogen fusion.

Based on data gathered from similar planets (if it is a planet), 2M0103 is too big to have formed in the normal way of core-accretion — that is, dust and debris sticking together and building up to form a mass. Instead, the team believes it would have been formed via "gravitational instability" (PDF), whereby the gravity of the gas inside a dust disc is significant enough to alter the structure of the disc, causing the dust to collapse in on itself and form a planet.

If 2M0103 is indeed a planet, it could well prove to be a valuable test case for studying theoretical planetary formation models.

You can read the paper "Direct imaging discovery of 12-14 Jupiter mass object orbiting a young binary system of very low-mass stars" (PDF) on the Cornell University website.

Via www.newscientist.com