Earth-like exoplanets around smallest red dwarf stars are particularly common
So-called M dwarfs are the most common stars in the Milky Way. A research team has determined around which of them Earth-like exoplanets are most common.
Artistic representation of a rocky planet near a red dwarf
(Image: ESO)
The smallest of the most common stars in the Milky Way are apparently orbited particularly frequently by Earth-like exoplanets. This is the result of an analysis led by astronomers at Heidelberg University. Following an analysis of more than a dozen red dwarf stars and a statistical analysis based on this, it was determined that such stars with less than 0.16 solar masses are orbited on average by around two exoplanets with less than three Earth masses. Given the frequency of this type of star and their longevity and stability, this is good news for the search for extraterrestrial life.
Searching for the most common stars in the Milky Way
As the team led by study leader Adrian Kaminski explains, precise spectrographic data was first collected for the analysis using the CARMENES instrument at the Calar Alto Observatory in AlmerĂa, Spain. A particularly precise search for exoplanets was carried out for 15 red dwarf stars – also M dwarfs – and four previously unknown ones were discovered. Three of them are around one to one and a half Earth masses, the fourth is noticeably larger. Statistical analyses were then carried out on the basis of the locations found in this selection of red dwarf stars to find out where Earth-like rocky planets are particularly widespread. The result is "truly remarkable", says Kaminski.
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Because the M dwarfs in the Milky Way are particularly common and radiate their energy fairly constantly over billions, exoplanets there could provide particularly stable environments for the development of life, the team classifies the finding. If we now know that a comparatively large number of Earth-like exoplanets orbit stars with less than one-sixth the mass of our sun, the study could also serve as an indication of where the search for life-friendly exoplanets would be most promising. This would then also apply to the search for extraterrestrial life itself. The research has been published in the journal Astronomy & Astrophysics.
(mho)
