Astronomers have discovered three Super-Earths and two Super-Mercuries in a star system. These planets are incredibly uncommon and unique. Super-Mercuries are extremely uncommon—only eight have been discovered thus far.
In the star system HD 23472, two “super-Mercury” worlds were found by ESPRESSO’s spectrograph. The extreme rarity of these planets has been discovered by astronomers. This study, which was published in Astronomy and Astrophysics, examined the relationship between the co-position of small planets and the position, temperature, and star parameters of the planets.
The purpose of this planetary system, according to Susana Barros, the project’s principal investigator and a researcher at the Institute of Astrophysics and Sciences of the Espaco (IA), is to characterize the coposition of small planets and to investigate the transition between having an atmosphere and not having one.
Star irradiation may be connected to the atmosphere’s evaporation. The researcher revealed, “Surprisingly, the study indicated that this system is composed of two Super-Mercuries, which are the closest planets to the star, and three super-Earths with considerable atmospheres.
Three of the six exoplanets in HD 23472 have masses that are smaller than that of the Earth. Using the radial velocity technique, it was discovered that the five planets were among the lightest exoplanets ever discovered. This method can identify minute changes in a star’s velocity brought on by nearby planets.
The European Southern Observatory’s (ESO) ESPRESSO spectrograph, which is mounted on the VLT, provided the great accuracy that enabled the discovery. In terms of coposition, super-Earths and super-Mercuries are the higher-mass equivalents to Earth and Mercury. The main difference between them is that super-Mercuries have more iron in them. This type of exoplanet is incredibly uncommon.
In reality, only eight—including the two newly discovered—are known. Mercury is one of the densest planets, although we don’t understand why it has a larger and more massive core than Earth and the other planets in our solar system.
Mercury is the hottest planet in the solar system, therefore its extreme temperatures may have melted some of its core, or its мantle may have been lost due to a massive impact. Finding other dense, Mercury-like planets orbiting other stars is crucial to comprehend the development of such objects.
It’s important to note that the discovery of two super-Mercuries, as opposed to one, in the same planetary system provides astronomers with a clear picture. Using the ESPRESSO spectrograph, we discovered a system containing two super-Mercuries for the first time. According to co-author and IAC researcher Alejandro Suárez, “This helps us understand how these planets descended.”
“The thought of a minor impact forming a Super-Mercury is already incredibly improbable; the idea of two major impacts occurring simultaneously looks incredibly improbable.” To fully understand how these two super-Mercuries evolved, according to co-author and IAC researcher Jonay González, more characterisation of the planet’s coposition is necessary.
For the first time, utilizing the Extremely Large Telescope (ELT) and its first-generation high-resolution spectrograph ANDES, researchers will be able to examine the surface composition or the existence of a fictitious atmosphere. The ultimate objective of the tea is to discover another planet like Earth.
Because there is an atmosphere, scientists can better understand how planetary systems develop and evolve. Also, it can determine if a planet is habitable. According to Barros, “We would like to continue this type of estimation to longer period planets with more appropriate temperatures.”
