An artist’s impression of the GJ 887 planetary system of super Earths. (Mark Garlick)

From the perspective of planet hunters and planet characterizers,  a desirable solar system to explore is one that is close to ours, that has a planet (or planets) in the star’s habitable zone,  and has a host star that is relatively quiet.  This is especially important with the very common red dwarf stars,  which are far less luminous than stars such as our sun but tend to send out many more powerful — and potentially planet sterilizing — solar flares.

The prolific members of the mostly European and Chilean Red Dots astronomy team believe they have found such a system about 11 light years away from us.  The system — GJ 887 — has an unusually quiet red dwarf host, has two planets for sure and another likely that orbits at a life-friendly 50-day orbit.  It is the 12th closest planetary system to our sun.

It is that potential third planet, which has shown up in some observations but not others, that would be of great interest.  Because it is so (relatively) close to Earth, it would be a planet where the chemical and thermal make-up of its atmosphere would likely be possible to measure.

The Red Dots team — which was responsible for the first detection of a planet orbiting Proxima Centauri and also Barnard’s star — describes the system in an article in the journal Science.  Team leader Sandra Jeffers of Goettingen University in Germany said in an email that GJ 887  “will be an ideal target because it is such a quiet star — no starspots or energetic outbursts  or flares.”

In an accompanying Perspective article in Science,  Melvyn Davies of Lund University in Sweden wrote that “If further observations confirm the presence of the third planet in the habitable zone, then GJ 887 could become one of the most studied planetary systems in the solar neighborhood.”

An artist’s impression of a flaring red dwarf star and a nearby planet. Red dwarfs are by far the most common stars in the sky, and most have planetary systems.  But scientists are unsure if they can support a habitable planet because many send out more large and powerful flares than other types of stars, especially at the beginnings of their solar lives. (Roberto Molar Candanosa/Carnegie/NASA)

GJ 877 is roughly half as massive as our sun — large for its type of star — and is the brightest red dwarf in the sky.… Read more