Astronomers at Harvard University have found that the smallest and most common types of stars in the universe - red dwarfs - very rarely have planets the size of Jupiter. This is reported in an article published in the arXiv preprint repository.

It is known that Jupiter played a dominant role in the evolution of our solar system, being the largest planet in it. The gas giant, which attracts many celestial bodies to itself, has set the stage for the Earth to become habitable. Thus, the absence of huge gas giants in red dwarf planetary systems suggests that some planets may not have evolved into habitable worlds.

The researchers studied a population of 200 small red dwarfs in the vicinity of the Sun. Each of them made up only 10 to 30 percent of the mass of the Sun. The observations were made between 2016 and 2022 at the Fred Lawrence Whipple Observatory in Arizona and at the Cerro Tololo Inter-American Observatory in Chile. Astronomers used the method of radial velocities, which consists in registering the "rocking" of a star due to the rotation of massive bodies around it.

Scientists have not found a single planet equivalent to Jupiter. Based on statistical uncertainties, the researchers determined that Jupiters are in short supply, found in less than two percent of low-mass red dwarf planetary systems. However, the authors of the study note that the absence of gas giants does not make rocky planets around red giants necessarily uninhabitable.