Bulgarian Scientists Discover Exoplanet Five Times the Mass of Earth

An international team of scientists, with leading participation of scientists from Sofia University, has discovered a new “super-Earth” exoplanet. The planet lies 91 light-years from Earth and has a mass five times that of the Earth.

Exoplanets are planets that orbit stars outside the Solar System. Scientists from the Faculty of Physics at Sofia University have been studying them for years and explain what defines a super-Earth.

Denitsa Stoeva, a PhD student at Sofia University’s Faculty of Physics and a researcher on the EXO-RESTART project: “A super-Earth is a planet whose mass is significantly larger than Earth’s but smaller than Neptune’s. In this case, our discovery has a mass five times that of Earth and falls squarely into this category.”

The newly discovered exoplanet orbits a star named Macondo, located in the southern constellation of Puppis. The star and its planet were named after the fictional town in Gabriel García Márquez’s novel One Hundred Years of Solitude.

Denitsa Stoeva, a PhD student at Sofia University’s Faculty of Physics and a researcher on the EXO-RESTART project, explained: “The planet orbits its star, but the star also moves around the common centre of mass. It is not static — it has a very slight wobble. We observe this very small trembling of the star.”

To date, over 6,000 exoplanets have been discovered, all named according to strict conventions.

Stoeva added: “Unfortunately, we cannot give it a nice Bulgarian name. The planet is named after its star, with a Latin letter added according to its order of discovery.

The super-Earth is the second planet discovered orbiting Macondo. Bulgarian scientists identified it by analysing data collected between 2004 and 2017 from the HARPS spectrograph, installed on a telescope at an observatory in Chile.