How many Earth-like exoplanets orbit M dwarf stars (Red dwarf stars), which are smaller and cooler than our Sun? This is what a recent study published in Astronomy & Astrophysics hopes to address as an international team of researchers investigated how many Earth-like exoplanets orbit low-mass stars, also called M dwarf stars, using data obtained from the CARMENES project. This study has the potential to help researchers better understand the formation and evolution of Earth-like exoplanets orbiting stars smaller than our Sun and what this could mean for finding life beyond Earth.
For the study, the researchers used the CARMENES spectrograph system at the Calar Alto Observatory in Spain that is designed to search for exoplanets orbiting M dwarf stars. The team used the radial velocity method, which measures wobbles between an exoplanet and its host star as they tug on each other, to observe 15 M dwarf stars with the goal of identifying new exoplanets. In the end, the researchers discovered four new exoplanets orbiting three separate stars with three of the exoplanets displaying masses between 1.03 and 1.52 Earths and orbits between 1.43 and 1.52 days. In contrast, the fourth exoplanet is estimated to be approximately 14.3 Earth masses with an orbit of 1,218 days (3.34 years).
“Small, rocky planets in the so-called habitable zone – the area around a star where water could exist in liquid form – are potential candidates for habitable worlds,” said Dr. Andreas Quirrenbach, who is the director of the Königstuhl Observatory at the Center for Astronomy of Heidelberg University and a co-author on the study. “Since M-dwarfs are very common and radiate their energy constantly into space over billions of years, they could provide stable environments for the development of life.”
While Earth orbits a larger, G-type star, identifying Earth-like exoplanets orbiting M dwarf stars challenges our understanding of the formation and evolution of exoplanets and could help scientists better understand more precise target worlds for finding life beyond Earth.
What new discoveries regarding Earth-like exoplanets orbiting M dwarf stars will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Astronomy & Astrophysics, EurekAlert!
Featured Image: Artist's illustration of exoplanets orbiting an M dwarf star. (Credit: NASA/JPL-Caltech/MSSS)
