Astronomers can’t seem to explain why a large planet would orbit a tiny star – in this case NGTS-1. The mismatch is more than just silly. It also demonstrates a flaw in our understanding of planet formation.
Planets and their stars are usually alike: Large planets orbiting large stars and small planets orbiting small stars. This makes sense, because more gas and dust available means there is the potential for both larger stars and larger planets.
That’s why the most recent planet discovered by researchers from the University of Warwick is so surprising. They found a giant planet about the size of Jupiter orbiting a star that’s not much bigger than that. The star in question, NGTS-1, is only about half the size of our sun, and the discovery of a gas giant around it stands to shake up our understanding of planetary formation.
According to our current theories of planetary formation, small stars like NGTS-1 have enough gravitational pull to form only small, rocky planets. They simply can’t attract enough gas and dust to form large gas giants like Jupiter. Or so we thought.
With this new discovery, scientists now have to reevaluate their theories of star formation. The challenge now is to come up with an explanation for how such small stars can form such massive planets. And considering how many unexamined small stars populate our universe, whatever explanation scientists come up with may have to apply to thousands of mismatched systems.