Gigantic exoplanets: Astronomers are revolutionizing our view of M dwarfs!

Gigantic exoplanets: Astronomers are revolutionizing our view of M dwarfs!

Research into exoplanets is an exciting field of astronomy that constantly provides new insights. An outstanding project in this area is the CARMENES program, which was developed at the Calar Alto Observatory in Spain and built at the Königstuhl State Observatory at Heidelberg University. The aim of this research is to discover exoplanets that orbit stars with less than a tenth to about half the mass of the Sun, so-called M dwarfs. These stars are the most common in the galaxy and exhibit easily measurable movements through the gravitational attraction of their planets, allowing astronomers to analyze how their orbits move uni-heidelberg.de reported.

As part of this program, researchers selected 15 stars from a catalog of 2,200 M dwarfs and analyzed the radial velocity data. Their analysis led to the discovery of four new exoplanets. The largest of these planets is already more than 14 times the mass of Earth and takes around 3.3 years to orbit its star. The other three newly discovered planets have much shorter orbital periods between 1.43 and 5.45 days and have masses of 1.03 to 1.52 Earth masses.

The meaning of M-dwarves

Statistical analyzes show that stars with less than 0.16 solar masses have on average around two planets with less than three Earth masses. However, it is noteworthy that larger exoplanets are less common among low-mass stars. Although we have already discovered around 5,000 planets outside our solar system, we have not yet been able to identify a perfect “twin” of Earth. Nevertheless, the newly identified planets meet the criteria for mass, radius and surface temperature, making them potential candidates for habitable worlds. M dwarfs may provide stable environments for life to develop, according to astronomers who participated from several countries such as Bulgaria, Germany, India, Norway, Spain and the United States.

The research was funded by, among others, the Spanish Ministry of Science, the European Union, the Bulgarian National Science Fund and the German Research Foundation. The results of their studies were published in the renowned journal “Astronomy & Astrophysics” and represent significant progress in the search for potentially habitable planets.

The discovery of gigantic exoplanets

In parallel to the findings of the CARMENES program, there have also been significant recent discoveries from the TESS (Transiting Exoplanet Survey Satellite) mission. Astronomers have discovered two large exoplanets, TOI-6303b and TOI-6330b, both larger than Jupiter and orbiting M dwarfs. TOI-6303b has a mass 7.84 times Jupiter's mass and a corresponding radius, while TOI-6330b is 10 times as massive as Jupiter and has a slightly smaller radius. Their orbital periods are approximately 9.5 days and 6.85 days.

The special properties of these M dwarfs, which are smaller and fainter than the Sun, make the discovery of planets easier because their habitable zones are closer. It is noteworthy that so far no large and Earth-like planets have been observed together in a system around M dwarfs. Both newly discovered planets have been confirmed by different telescopic observations, offering observers the opportunity to learn more about their formation. Scientists debate two main theories of planet formation: core accretion and gravitational instability. The available data suggests that the gigantic exoplanets could have formed through one of these two mechanisms.

The search for other large exoplanets around M dwarfs remains of central importance for astronomers. Through this research, they hope to learn more about the formation and influence of such planets on smaller, nearby worlds. These discoveries expand the list of known planets beyond our solar system and further questions about their potential habitability, as astronomy continues to establish itself as one of the most exciting fields of scientific research.