An international team of astronomers, including several Spaniards, discovered strange solar system with six planets in orbit around a bright Sun-like star located 100 light-years from Earth called HD 110067. The discovery was presented in a paper published in the journal Naturewhere they suggest that the system has changed little since its formation over a billion years ago.

Although multiplanetary systems are common in our galaxy, systems in a tight gravitational formation known as a resonance are much less commonly observed.

resonant configuration it means that orbits are synchronized in a special way. In this case, the planet closest to the star rotates three times for every two revolutions of the next planet, which is called a 3/2 resonance, a pattern that repeats among the four closest planets. In the case of the most distant planets this is four orbits for every three subsequent planetsresonance 4/3.

Resonant orbital systems like this one extremely important because they inform astronomers about the formation and subsequent evolution of a planetary system. Planetary systems tend to form in resonance, but can be easy to disturb. For example, a very massive planet in the system, a close encounter with a passing star, or any type of merger or collision could upset the delicate balance. Therefore, discovering a resonant system is like observing a fossil planetary system.

HD 110067 invites us to study it further because it shows us the unchanged configuration of a planetary system, maintaining its resonance since its formation: it is likely that the planets have been practicing the same gravitational dance since the formation of the system, billions of years ago. . Moreover, we are talking about the brightest system four or more planets are known. Since all these planets have smaller than Neptune and likely vast atmospheres, are ideal candidates for studying their atmospheric composition with the James Webb Space Telescope.

Juan Carlos Morales, Guillem Anglada-Escudé and Ignasi Ribas, all researchers from the ICE (Institute of Space Sciences) CSIC and IEEC (Institute of Space Research of Catalonia), took part in the study, presenting observations made with Carmenes, an exoplanet search from the Calar- Observatory Alto, developed in collaboration with the Institute of Astrophysics of Andalusia (IAA-CSIC).

“High-resolution spectroscopic observations of Carmen over a year, together with the HARPS-N spectrograph, were used to determine the masses of three planets in the system and set strict limits on the others, showing that they are what we call Sub-Neptune class planets“Explains Juan Carlos Morales, researcher at ICE-CSIC and IEEC, in a statement.