A temperate world, ten light-years out

Field notes from GJ 887 d: a temperate world, ten light-years out

…she didn't point at the sky. She pointed at a graph of a star quietly rocking toward us and away, and said: there's a world doing that…

Let me set this down from the beginning, because how I came to be standing in a cold dome after midnight is half of what I learned. I had written to an astronomer who hunts planets she will never photograph — she finds them in the way a star wobbles.

A planet and its star really orbit each other, like a hammer-thrower leaning back against the hammer. The star traces a tiny circle, and as it swings toward us and away its light compresses, then stretches — a Doppler shift (the same effect that drops the note of a passing siren), here amounting to mere centimetres per second. This is radial velocity: from that whisper of motion she reads out an unseen world's mass and its year.

Her star was GJ 887 — the old catalogues call it Lacaille 9352 — a red dwarf just 10.7 light-years away. A light-year is how far light flies in a year, about 9.5 trillion kilometres; GJ 887 is among the very nearest stars to our Sun, and one of the calmest red dwarfs known — it barely flares, which is kind to anything orbiting it.

In 2026 she and her colleagues confirmed a new world there: GJ 887 d, a super-Earth (a rocky planet heavier than Earth) sitting squarely in the star's habitable zone — the Goldilocks band where a surface could hold liquid water. It rounds its dim sun every fifty days. And it is the second-closest planet in any star's habitable zone we have ever found.

and this is what I learned

Filed under

Astronomy → exoplanets → habitable-zone super-Earths → GJ 887 d

The short of it

Ten light-years away, a calm red dwarf turns out to carry a temperate, rocky world — the nearest fresh 'Goldilocks' planet in years.

The long of it

GJ 887 d — minimum mass about 6.5× Earth's, a 50.8-day orbit of the M-dwarf GJ 887 (Lacaille 9352), 10.7 light-years off — was teased out of years of radial-velocity data and confirmed in 2026 (Astronomy & Astrophysics). It is the second-closest habitable-zone planet known, after Proxima b, and orbits one of the nearest, brightest, quietest red dwarfs — which makes it a prime target for the next generation of telescopes hunting for air on other worlds.

— The Curator

A note on what is and isn't known: a radial-velocity mass is a minimum mass, and "habitable zone" means "could hold liquid water," not "does." No one has seen this planet's face or sniffed its air — yet.

SourcesAstronomy & Astrophysics (2026), NASA Exoplanet Archive, ESO