Washington: The nearby star system Fomalhaut has been discovered to be not just a double star, as astronomers had earlier thought, but one of the widest triple stars known.
Researchers have shown that a previously known smaller star in its vicinity is also part of the Fomalhaut system.
Eric Mamajek, associate professor of physics and astronomy at the University of Rochester, and his collaborators found the triple nature of the star system through a bit of detective work.
"I noticed this third star a couple of years ago when I was plotting the motions of stars in the vicinity of Fomalhaut for another study," Mamajek said.
"However I needed to collect more data and gather a team of co-authors with different observations to test whether the star`s properties are consistent with being a third member of the Fomalhaut system," he said.
By carefully analyzing astrometric (precise movements) and spectroscopic measurements (that allow the temperature and radial velocity to be determined), the researchers were able to measure the distance and speed of the third star.
They concluded that the star, until recently known as LP 876-10, is part of the Fomalhaut system, making it Fomalhaut C.
The findings are set to be published in the Astronomical Journal.