Neighbor star found to have five planets

HATFIELD, England, Dec. 19 (UPI) -- Five planets are orbiting a sun-like star not far the Earth, one in the so-called "habitable zone" where liquid water can exist, British astronomers say.

An analysis of existing planet-hunting data by astronomers at the University of Hertfordshire with international colleagues uncovered the quintet of planets circling the star Tau Ceti, the BBC reported.

The star is the second nearby one known to host planets, joining Alpha Centauri, our sun's closest neighbor.

The five planets include worlds with masses between two and six times that of Earth, with orbital periods ranging from 14 to 640 days, astronomers said.

One of them, dubbed HD 10700e, orbits about half as far from Tau Ceti as the Earth does from the Sun, but because Tau Ceti is slightly smaller and dimmer than our Sun that puts the planet in the star's habitable zone.

Tau Ceti's relative closeness to our sun makes it an ideal candidate for studies of exoplanets, astronomers said.

"It's a star on which we have a lot of data -- an order of magnitude more data than we have for pretty much any other star," Hertfordshire researcher Hugh Jones said.