Astronomers believe it should not exist, at least according to current theories.
It is a giant planet called GJ 3512b. It is similar to Jupiter, but is unusually large compared to the orbit around it.
This contradicts the widespread idea about how the planets are formed.
The rotating star, which is 284 billion kilometers away, is an M-type red dwarf most common in our galaxy.
The finding was made by an international team of researchers and was published this week in Science.
"It is very exciting because we have long wondered whether giant planets like Jupiter and Saturn could form around such small stars," said Professor Peter Whitley of Warwick University in the UK who was not involved in the study.
“Belief in general so far it has been these planets did not exist, but we couldn't be sure, because the small stars are very weak, which makes it difficult to study, even though they are much more common than stars like the Sun, "Whitley told the BBC.
Researchers used telescopes in Spain and the United States followed by gravitational acceleration of the vein, potentially caused by the planets orbiting it.
The red dwarf has a mass larger than the GJ 3512b, but the difference in its size It is much smaller than between, for example, the Sun and Jupiter.
The star has a mass that is at most 270 times the size of the planet. As a comparison, it is estimated that The Sun is 1,050 times as massive as Jupiter.
Astronomers use computer simulations to build their theories on how planets are formed from clouds or gas and dust "orbits" orbiting young stars. These simulations predict that many small planets should cluster around small dwarf stars of type M.
"Around such stars there should be only Earth-sized planets or something of a mass superpower, "said study co-author Christoph Mordassini, a professor at the University of Bern, Switzerland.
An example of a real-life planetary system corresponding to the theory described is a star known as Traptist-1.
This star, which is 369 billion kilometers from the Sun, has a system of seven planets, all with approximately equal or slightly lower masses to those on Earth.
"However, GJ 3512b is a A giant planet with a mass about half that of Jupiter and, therefore, at least an order of magnitude larger than the planets provided by theoretical models for such a small star, "Professor Mordassini said.
This finding challenges the widespread idea of planet formation, known as nucleus accumulation.
"In principle, we think that the giants of the planets begin their lives as ice cores, orbiting in a gasoline disc that surrounds the young star and then growing rapidly attracting gas to themselves," Professor Whitley said.
"But the study's authors argue that the discs around the small stars do not provide enough material for this to work. On the contrary, they think it is more likely that the planet was suddenly formed when part of the disk collapsed because of its own weight. "
The authors of the article by Science they suggest that such a collapse can occur when a disk of gas and dust has more than a tenth of the star star's mass. Under these conditions, the gravitational effect of the impeller is insufficient to keep the disc stable.
The question of the disk is extends inward to form a gravitationally united group that eventually develops a planet.
The idea behind this study predicts that this collapse is going far beyond the star, while the planets can grow much closer.
GJ 3512b has a oval orbit 204 days around his vagina. Most of the time, the distance between this planet and its star is less than that between Mercury and the Sun.
The eccentric orbit of this gas giant indicates the presence of other giant planets orbiting outside that could have distorted its orbit.
"Until now, the only planets whose formation was compatible with the discs of the disc were a small number of young, warm and very massive planets beyond their host stars," said Hubert Klahr of the Max Planck Institute for Astronomy in Germany and co-author of the study.
"With GJ 3512b, we now have an extraordinary contender for a planet that could emerge from instability on a star-shaped disk with a very small mass. This finding makes us look at our models. "