[LINK] More on GU Piscium b

[rfmcdonald]

Last Wednesday I pointed readers to The Dragon's Gaze, which linked to the discovery paper for GU Piscium b. This exoplanet, much more massive than Jupiter, was found orbiting its small red dwarf star at a great distance. Today CBC has reported in greater detail on the planet, which turns out to have been found by a largely Canadian team.

A gigantic planet-like object like no other has been found circling a tiny star at a record distance.

The object is a kind of "super Jupiter" – a gas giant about 10 times bigger than the biggest planet in our solar system, says Marie-Eve Naud, a PhD student at the University of Montreal and lead author of a scientific report describing the planet. The study is being published in the Astrophysical Journal this week.

GU PSc b is 2,000 times farther from its star than the Earth is from the sun, 67 times farther than Neptune and 50 times farther than Pluto — more distant than any planet ever discovered by a long shot, said René Doyon, a University of Montreal professor who is Naud's co-supervisor and co-author of the report.

But despite the vast distance between them, the planet is bound to its star via gravity, Doyon told CBCNews.ca. "The planet is actually moving with its star."

The researchers estimate that the planet completes its orbit around the star about once every 80,000 years. The star itself is located about 155 light years away, in the constellation Pisces, and is a small, young one, with just a third the mass of our sun.

On the other hand, the unusual object is so big that it may not be a planet at all. It may instead qualify as a brown dwarf or a "failed star" too small to ignite the nuclear reactions that power stars.

"Either way this is exciting," Doyon said. If it's a planet, it shows that planets can form farther away from stars than previously thought, and may not always form from the "planetary disk" of dust near a star. If it's a brown dwarf, it shrinks the known size limit of objects that can form in a way similar to the way stars form.