Dec 03 2008
Universe may abound with icy planets
SYDNEY: New observations from NASA’s Spitzer Space Telescope suggest that icy planets are common around young, bright stars.
U.S. researchers say they have found evidence of icy planets – ranging in size from smaller than Pluto to as big as Neptune – around half of all ‘A-type’ stars in a nearby star cluster, called NGC 2232.
A-type stars are about twice as massive and twice as hot as the Sun.
“Like car crashes”
The researchers used data from NASA’s Spitzer Space Telescope and the ROSAT All-Sky Survey (a now defunct international satellite X-ray observatory) to observe A- and B-type stars that dwell 25 million light-years away in the constellation Monoceros, a faint group of stars between the Orion and Gemini constellations.
As they detail this week in the Astrophysical Journal, the researchers found one star ringed with a warm dusty disk where rocky planets might form, and 12 stars which had cold, dusty disks which they claim is made from the debris of icy planet-forming collisions.
“Planets grow by accreting small, kilometre-sized objects via collisions. Like car crashes, these collisions produce debris,” said lead author, U.S. astrophysicist Thayne Currie from the Harvard-Smithsonian Centre for Astrophysics in Cambridge, Massachusetts.
Source: Cosmos Online – click here for full article
