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This is Scientific American’s 60-Second Science. I’m Christopher Intagliata. Got a minute?
Astronomers¹ have already discovered hundreds of exoplanets. But make way for the new kid, which is orbiting a kind of star that models say it shouldn’t.
Researchers found the exoplanet while looking at the star HIP² 13044—or Sergio, for Star of Extra-Galactic Origin. It’s in what once was a separate galaxy³, which the Milky⁴ Way gobbled up billions of years ago.
The scientists saw Sergio wobbling due to the gravitational tug⁵ of a Jupiter-sized gas planet, which the scientists dubbed⁶ Sergio Junior. They detail their find in the journal Science.
You don’t ordinarily find planets hanging around a star like Sergio. First, it's really old—past the Red Giant phase, when stars balloon in size and swallow up planets in close orbits. And planets tend to form around metal-rich stars, like our Sun. But Sergio has only one percent the metal content of our Sun. That doesn't jibe⁷ with one widely accepted model of planetary formation.
The Sergios may offer a glimpse of the future of our own planetary system—in about five billion years. We hope to be back then with an update.
Thanks for the minute. For Scientific American’s 60-Second Science, I’m Christopher Intagliata