Say hello to Kappa Adromedae b, a world so big it defies conventional classification
About 170 light-years away, scientists snapped a photo of a rare alien exoplanet that's 13 times bigger than Jupiter. Officially named Kappa Adromedae b ("Kappa And b," for short), the massive world blurs current distinctions between planets and small stars, so in the meantime scientists are simply dubbing it a "super-Jupiter." Here's what you should know about the gigantic world:
What is Kappa And b exactly?
The reddish planet orbits a bright star called Kappa Adromedae — a sun-like object so massive that it's 2.5 times larger than our own sun. The star is relatively young at just 30 million years old (our sun is 5 billion years old), making the orbiting Kappa And b similarly adolescent. The two objects are also really far away from one another, with Kappa And b's orbit even beating out Neptune's, the outermost planet in our solar system.
Why is it so difficult to classify the exoplanet?
Because the unique planet is so large and hot. "According to conventional models of planetary formation, Kappa And b falls just shy of being able to generate energy by fusion, at which point it would be considered a brown dwarf rather than a planet," said NASA's Michael McElwain through an official release. "But this isn't definitive, and other considerations could nudge the object across the line into brown dwarf territory."
How did scientists capture photos of Kappa And b?
Taking photographs of far-off planets isn't easy. Of the 850 known planets, fewer than a dozen have ever been photographed, says Joanna Carver at New Scientist. Part of the difficulty is that the glare from host stars can conceal the light given off by a nearby planet. "It's kind of like seeing a firefly next to a lighthouse," says Joseph Carson, an assistant professor of astronomy at the College of Charleston in South Carolina. In this case, researchers had to remove the light from Kappa And b's parent star with digital software, which revealed the big, bright super-Jupiter orbiting around it.
What does it mean for our understanding of the galaxy?
The discovery of Kappa And b shows that "large stars are capable of producing exceptionally large planets," says George Dvorsky at io9. Plus it indicates that these planets can anchor a parent star at greater distances than our own solar system. "This planetary system is very different form our own," says Thayne Currie of the University of Toronto, who co-authored the study.
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