In planetary systems, generally speaking, planets and stars rotate in the same direction. Take our own solar system. Our sun rotates almost exactly in the same direction as the orbits of the earth and other planets, but with a small tilt of 6 degrees.It used to be thought that all planetary systems worked in a similar way, but studies have shown that this is not necessarily the case.
Astronomers have discovered several stars whose rotation is different from that of the planets around them, but a recent study found that a star's rotation direction is opposite to the two planets in its system, not one, but two.
The k2-290 system consists of three stars, two of which revolve around its main star k2-290a. Interestingly, k2-290a tilts 124 degrees compared with the two planets around it. In other words, it rotates in the opposite direction.
Maria Hjorth and Simon Albrecht of the University of Aarhus in Denmark observed the unprecedented scene and published their findings in the proceedings of the National Academy of Sciences on Monday.
The two planets orbiting k2-290a are on the same plane, so it's more complicated to explain the direction difference.