Potential Planet System Around Small Star

U.S. astronomers have discovered a disk of dust — a possible breeding ground for planets — around a surprisingly small star.

Using the Spitzer Space Telescope, astronomers at the Harvard-Smithsonian Center for Astrophysics said their finding raises the possibility that new planets could form around objects that are not much bigger. They also said the disk suggests Earth-sized planets could form and perhaps thrive orbiting an object too small to shine via nuclear fusion.

It’s an exciting possibility–one that hasn’t been explored extensively because this is the first evidence for the building blocks of planets around such a small object, said team leader Kevin Luhman.

The object in question, called a brown dwarf and named OTS 44, is about 500 light-years away from Earth in the southern constellation Chameleon. OTS 44 is around 15 times heavier than Jupiter, placing it near the dividing line between brown dwarfs and planets. Brown dwarfs generally run between 15 and 70 times Jupiter’s mass.

At a temperature of 3,600 degrees Fahrenheit, OTS 44 is the coolest and least massive brown dwarf known to have a planet-forming disk, the astronomers said.