By Irene Klotz
Fri Jul 2, 2010 08:30 AM ET
object eight times the size of Jupiter is confirmed to be orbiting a
Scientists have no explanations for how the object, which resembles a
planet, formed so far away.
Follow-up studies could determine if the object is a planet or a
previously undiscovered stellar companion.
A planet-like object about
eight times the size of Jupiter is locked in orbit around very young
star, though the exact relationship between the two remains a mystery.
Circling 300 times farther from the star than Earth orbits the sun,
the object could be a planet, perhaps one that was catapulted out into
the nether regions after a collision or close encounter with an as-yet
undetected sibling planet.
"There is no theory for how a true planet can form at 300 AU
(astronomical units, with one unit equal to 93 million miles, the mean
distance between Earth and the sun). It's not really a lack of
imagination. It's a lack of physics," California Institute of Technology
astronomer John Johnson told Discovery News.
Current theories, observations and computer models show that planets
form from a disk of gas and dust that circles young stars. Less material
is available as the distance to the parent star grows.
"You actually have to have material out there to have the planet
forming," Johnson said.
Another option is that the object, designated as 1RXS
J160929.1-210524 b and located about 500 light-years away in the
constellation Scorpius, is a new type of failed star -- something akin
to a brown dwarf, though about half the size -- which formed along with
the primary star about 5 million years ago.
But scientists similarly are at a loss to explain how such a
relatively small object could have survived the stellar birthing
Please click on "external source" to access the entire article. Comments are welcomed as to what this object might be...a planet?