During the observation of the star system HD 23472, using an ESPRESSO spectrograph, scientists found three superearths and two supermercures, the last of two types of exoplanet being very rare and only eight before that.
The purpose of the study, published in Astronomy & Astrophystics, was to describe the composition of small planets and to understand how they varied according to the planet ' s position, temperature and properties. It turned out that the system consisted of three supergrounds with their atmosphere and, surprisingly, two super-mercurys.
Of the five planets in the HD 23472 system, three have less than the Earth's mass. This is one of the lightest exoplanet, their masses measured using the ray speed method using ESPRESSO. The Spectrograph was installed on the Very Big ESO Telescope in Chile.
The planet Mercury in the solar system has a relatively large core and relatively small mantle than other planets, but astronomers don't know why.