What could be lonelier than free-floating in the cold depths of space, without a planet or a host sun to hang out with? That’s the fate of a recently discovered brown dwarf spotted in a star family about 150 light years from Earth.
The free-floating dwarf, dubbed WISEA 1147, lives in a star family called the TW Hydrae, Phys.org reported. This family is made of very young stars and therefore the dwarf probably is, too — about 10 million years old.
WISEA 1147 was found in a collection of pictures taken by NASA’s Wide-field Infrared Survey Explorer (WISE) in 2010, and some taken by the Two Micron All Sky Survey (2MASS) a decade earlier. Spotting a dwarf like this one is tricky business; to find one, astronomers must look at stars nearby to determine if an object has moved relative to their position over time. They’re looking for close objects, which will seem to move in front of distant stars.
This free-floating world was seen as a brilliantly “red” speck in the 2MASS images. The color reveals that it’s dusty and young.
“The features on this one screamed out, ‘I’m a young brown dwarf,'” said Adam Schneider of the University of Toledo.
According to USA Today, NASA believes our galaxy is teeming with free-floating, lonely worlds. They aren’t held down by an orbit and live miles from any host star.
So far, they know this one has a mass five to 10 times that of Jupiter (the largest planet in our neighborhood in space), which makes it pretty heavy
These objects are a great mystery. Scientists don’t know whether they are planets cast out by other solar systems or brown dwarfs that formed in space all alone. Such objects form like stars but don’t have what it takes to fuse atoms in their core and produce starlight, ABC News explained. For an object to become a star, it needs to be 100 times the mass of Jupiter. Our sun is 1,000 times that planet’s mass.
WISEA 1147 is one of the few free-floating worlds scientists have discovered that is very clearly a dwarf, because it’s probably too young to be anything else.
Since the dwarf lives in space with a star family estimated to be 10 million years old, it’s probably that old, too. But planets need much more time to develop and even longer to be ejected from a solar system.
That makes it most likely that this object is a dwarf, and it will be studied more to confirm that fact.
“With continued monitoring, it may be possible to trace the history of WISEA 1147 to confirm whether or not it formed in isolation,” said Schneider.
It’s most advantageous feature is its loneliness in space. Such worlds are easier to study than planets because they’re easier to see: no pesky light from a host sun to obstruct the view. Plus, they’re pretty similar to planets. This world can be a kind of stand-in and help scientists learn more about composition and weather patterns.
“We are at the beginning of what will become a hot field – trying to determine the nature of the free-floating population and how many are planets versus brown dwarfs,” NASA’ Davy Kirkpatrick.
There are probably billions of free-floating worlds in space. Some of them are probably low-mass brown dwarfs, while others are actual planets sent away from their home solar systems. Scientists have no idea how many of each category exist and figuring that out isn’t easy. Because such bodies live in isolated regions of space, they’re pretty hard to study.
[Image via Diego Barucco/Shutterstock]