While observing the star system HD 23472 with the ESPRESSO spectrograph (ESO), a team led by Instituto de Astrofísica e Ciências do Espaço's (IA3) researcher Susana Barros (IA & Dep. de Física e Astronomia—Faculdade de Ciências da Universidade do Porto), found three super-Earths and two super-Mercuries. This last type of exoplanet is still very rare—counting these two, there are only eight known super-Mercuries.