New planet orbiting its 'Sun-like' star

A planet about eight times the mass of Jupiter has been confirmed to orbit a Sun-like star, says a study.

The newly-confirmed planet is about 300 times farther from its star than Earth is from the sun, making it the least massive planet to orbit at such a great distance from its host star.

Direct imaging shows water vapour, carbon monoxide and molecular hydrogen in the planet's atmosphere.

The discovery, first reported in September 2008, was made using high-resolution technology at the Gemini Observatory.

These latest results were based on a research led by David Lafrenière of the University of Montreal and a researcher at the Centre for Research in Astrophysics of Quebec.

The suspected planetary system required further observations to confirm that the planet and the star were indeed moving together.

"Back in 2008, what we knew for sure was that there was this young planetary mass next to a young Sun-like star," Lafrenière says. The extreme proximity of the two objects strongly suggested that they were associated and not just aligned by chance.

"Our new observations rule out this chance alignment possibility and thus confirms that the planet and the star are related to each other," Lafrenière added.

With its initial detection by the team using the Gemini Observatory in April 2008, this object became the first likely planet known to orbit a sun-like star that was revealed by direct imaging.

At the time of its discovery, the team also obtained a spectrum of the planet and was able to determine many of its characteristics, which are confirmed in this new work, says a university release.

"In retrospect, this makes our initial data the first spectrum of a confirmed exoplanet (a planet outside the solar system) ever," Lafrenière says.

These findings were published in the Astrophysical Journal.