Discovery of an extremely rare planetary system with two exoplanets that “turn upside down” around their star

The universe always has surprises in store for us. Until recently, for example, we’ve seen astrophysicists at the Massachusetts Institute of Technology discover signs of what appears to be galactic cannibalism in an ultra-thin dwarf galaxy more than 160,000 light-years from our planet.

A recently published article from AARHUS University reports a new finding. An international team of researchers led by Maria Hjorth and Simon Albrecht from the Stellar Astrophysics Center at Aarhus University in Denmark has discovered a very rare planetary system that is 897 light years from Earth. It’s called K2-290 and has two exoplanets that rotate in a direction opposite that of the main star.

An extremely rare phenomenon

It was previously believed that the equatorial line of a star must necessarily be aligned with the orbit of the celestial bodies moving around it, since these objects are believed to come from the same molecular cloud. In addition, the planets and the star must rotate in the same direction as the sun and its planets do. However, the K2-290 system offers a completely different reality. Note that this star system is made up of three stars and two planets orbiting the main star.

The affected protoplanetary disk

In contrast to the planets in the solar system, which rotate in the same direction as the sun, the two planets in the K2-290 system orbit their star in almost opposite directions. According to astronomers, the axis of rotation of the star K2-290 A is tilted 124 degrees compared to the planets.

Scientists attribute this unusual formation to the protoplanetary disk. The latter is in fact a disk of matter that revolves around a young star for several million years after its birth. This rotation is usually in the same direction as that of the star. However, it was different with the K2-290 system. It turns out that the gravity of a nearby star caused the disk to tip over.

A very rare phenomenon! https://t.co/9DWEbzMmwo

– Alexandre (@ Ar4kiel) February 26, 2021

The result of the cooperation of several universities

It should be noted that this distant star system, which is approximately 900 light years from Earth, is not the first “wrong” set of planets / stars discovered by astronomers. Another had been discovered a little over 10 years ago. However, according to Joshua Winn of Princeton University, this is an extremely rare case.

The new finding was published in the journal PNAS. It is the result of a collaboration between several universities, including Aarhus University in Denmark, Princeton University, Pennsylvania State University, the University of Toronto and the Tokyo Institute of Technology.