Granada (EFE).- Astronomers from the Institute of Astrophysics of Andalusia and the University of Granada, in collaboration with NASA, have discovered a unique new planetary system of its kind that researchers consider key to understanding how planets are formed.
It is the so-called TOI-2096, made up of a “super-Earth” and a “mini-Neptune” that orbit a cold and nearby star in a synchronized dance, the University of Granada (UGR) reported this Wednesday.
According to the researchers, TOI-2096 “may be the Rosetta Stone” they were looking for to understand how planetary systems form.
The finding has been possible with the collaboration between research centers and European and North American universities, led by the Institute of Astrophysics of Andalusia (IAA-CSIC).
The system was initially identified by NASA’s Transiting Exoplanet Survey Satellite (TESS) mission, a space mission that searches for planets around bright, nearby stars.
The support of telescopes
According to Francisco Pozuelos Romero, IAA-CSIC researcher and lead author of the scientific article recently published in the journal “Astronomy & Astrophysics”, TESS is conducting a search for planets throughout the sky using the transit method, that is, “monitoring the stellar brightness of thousands of nearby stars waiting for a slight dimming, which could be caused by the passage of a planet between the star and the observer.
However, despite its power to detect new worlds, Pozuelos explained, the TESS mission needs support from ground-based telescopes to confirm the planetary nature of the detected signals.
The planets TOI-2096 b (super-Earth) and TOI-2096 c (mini-Neptune) were observed with an international network of terrestrial telescopes, which has allowed their confirmation and characterization.
“Making an exhaustive analysis of the data, we found that the two planets were in resonant orbits, that is, for every two orbits of TOI-2096 b, TOI-2096 c performs one,” according to the researcher.
This configuration is very particular and due to it, the planets interact strongly in a gravitational way, which makes it possible to obtain their masses, something that the scientific team is now doing with ultra-precise measurements using the 2.2-meter telescope of the Calar Alto Observatory, he adds. Pedro Amado, researcher at the IAA-CSIC and co-author of the article.
Radium Valley
Researchers estimate that the radius of TOI-2096 b is 1.2 times that of planet Earth, hence the name super-Earth.
For its part, the radius of TOI-2096 c is 55% smaller than that of Neptune (1.9 times terrestrial radii), which is why it has been called mini Neptune.
These sizes could shed light on the anomaly known as Radio Valley, that is, the absence of exoplanets with radii between 1.5 and 2.5 Earth radii, something that is still not understood today.
For Juan Carlos Suárez, a researcher at the UGR, thanks to the global analysis of the data carried out on the high-performance computing servers of this academic institution, they have been able to understand that it is a “really unique” system.
“The formation of small planets, less than four Earth radii, remains a mystery today. There are different planetary formation models trying to explain how planets with sizes between Earth and Neptune form, but none quite fit the observations”, he pointed out.
TOI-2096 is the only system found to date that has a small planet, probably rocky, and a larger one just the right size where all the models contradict each other.
Hence, the researchers maintain that TOI-2096 “may be the Rosetta Stone they were looking for to understand how planetary systems are formed.”
