An international team of researchers from Australia, the United Kingdom and the United States have discovered a massive alien planet that orbits its host star at a distance that is 7,000 times farther compared to Earth's distance from the sun.
In a study featured in the journal Monthly Notices of the Royal Astronomical Society, astronomers from several research institutions, including the University of Hertfordshire and the Australian National University (ANU), tracked down the host star of a gas giant exoplanet designated as 2MASS J2126-8140.
When it was first discovered, scientists flagged 2MASS J2126-8140 as a potential lonely or free-floating planet because of its relatively young age and low mass.
However, further research [pdf] has shown that the exoplanet does indeed orbit a star but at a far greater distance than anything researchers have ever observed before.
ANU researcher Dr. Simon Murphy and his colleagues found that the star in question is a red dwarf named TYC 9486-927-1, which is located 6,900 astronomical units (AU) from 2MASS J2126-8140. This means that the exoplanet is roughly 1 trillion (1 million million) kilometers or 600 billion miles away from its host star.
"We were very surprised to find such a low-mass object so far from its parent star," Murphy said. "There is no way it formed in the same way as our solar system did, from a large disc of dust and gas."
At this distance, TYC 9486-927-1 would appear only as a moderately lit star in the sky of 2MASS J2126-8140. It would also take almost a month before any light from the red dwarf star reaches the exoplanet.
Murphy and his fellow researchers have been studying the 2MASS J2126-8140 as part of a survey involving thousands of brown dwarfs and young stars that are found near the solar system.
After finding out that the 2MASS J2126-8140 exoplanet and the TYC 9486-927-1 red dwarf star are both roughly 100 light years away from Earth, the researchers proceeded to compare the motion of the two objects through space. They were able to determine that the exoplanet and the star were moving together.
Murphy said that they believe 2MASS J2126-8140 and TYC 9486-927-1 were both formed from a concentration of gas in space that pushed them in the same direction together. This event likely occurred somewhere between 10 million and 45 million years ago.
Murphy added that the two massive objects must have existed in a highly dense environment, causing them to be barely bound together. If there were any other star nearby, it would have caused the orbit between 2MASS J2126-8140 and TYC 9486-927-1 to be severely disrupted.
