Planets consist of disks of gas and dust that rotate in the same direction as the young stars around which they formed. For this reason, there is generally no major mismatch between the orbital planes of the star and the planet. However, GJ 3090 b, discovered in 2022, completely breaks this rule.
A sub-Neptune with a radius 2.2 times larger than Earth and 4.5 times the mass, it forms an angle of a staggering 136 degrees with the equatorial plane of its star.
THE REASON FOR THE MYSTERIOUS INCOMPATIBILITY IS UNKNOWN
This situation, detected as a result of precise measurements made by the NIRPS instrument at La Silla Observatory, marks an unprecedented exception. To date, scientists have discovered only five systems with very high orbital inclination.
But unlike these, there is no giant planet or brown dwarf in GJ 3090 b’s system that could disrupt the orbit to this extent. This requires astronomers to reconsider currently accepted models of planet formation processes.
A NEW THEORY OF FORMATION
Experts from the research team state that in the absence of a giant companion, this unusual situation can be explained by a different scenario. It is estimated that the star may have swallowed a secondary disc material in the opposite direction and out of alignment in the past, and the planet was formed within this disc.
These findings, published in the journal Astronomy & Astrophysics, once again reveal how complex and diverse structures exoplanet systems can have.
