Washington, June 30 (ANI): A planet just about eight times the mass of Jupiter is orbiting a Sun-like star at over 300 times farther from the star than the Earth is from our Sun, astronomers have confirmed.
This is the least massive planet known to orbit at such a great distance from its host star.
The discovery, to be published in an upcoming issue of The Astrophysical Journal, utilized high-resolution adaptive optics technology at the Gemini Observatory to take direct images and spectra of the planet.
First reported in September 2008 by a team led by David Lafreniere (then at the University of Toronto, now at the University of Montreal and Center for Research in Astrophysics of Quebec), the suspected planetary system required further observations over time to confirm that the planet and star were indeed moving through space together.
Lafreniere said: "Back in 2008 what we knew for sure was that there was this young planetary mass object sitting right next to a young Sun-like star on the sky."
The extremely close proximity of the two objects strongly suggested that they were associated with each other but it was still possible (but unlikely) that they were unrelated and only aligned by chance in the sky.
Lafreniere said: "Our new observations rule out this chance alignment possibility, and thus confirms that the planet and the star are related to each other."
With this confirmation by Lafreniere and colleagues, the system, known as 1RXS J160929.1-210524 (or 1RXS 1609 for short), provides scientists with a unique specimen that challenges planetary formation theories due to its extreme separation from the star.
Co-author Ray Jayawardhana of the University of Toronto. said:
"The unlikely locale of this alien world could be telling us that nature has more than one way of making planets. Or, it could be hinting at a violent youth when close encounters between newborn planets hurl some siblings out to the hinterlands."
With its initial detection by the team using the Gemini Observatory in April of 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.
"In retrospect, this makes our initial data the first spectrum of a confirmed exoplanet ever!" said Lafreniere.
The spectrum shows absorption features due to water vapor, carbon monoxide, and molecular hydrogen in the planet's atmosphere. (ANI)