Star system, 15 light-years
Gliese 876 and its four planets
GJ 876 c is an exoplanet about 14 times Earth's width (a size estimated from its mass), about 1.2 times Jupiter's, 15 light-years away, orbiting in its star's computed habitable zone.
Gliese 876 is a star of spectral type M2.5V, 15 light-years from us, with four known planets. This page takes them one at a time.
Drawn at the system's own scale, every orbit from the Archive's numbers.
What is measured, what is computed, what is imagined.
measured The period, and where the table says so the width and the mass, by the method named in each section.
computed Anything marked computed: the size of an orbit where Kepler's third law corrects the table, the temperature of a bare ball at that distance, the starlight received, and the habitable zone.
imagined The picture is an artist's impression. Nobody has seen the surface of a planet of another star: its colour, clouds and land are not known, and the share picture says so in its corner.
The planets
GJ 876 d
GJ 876 d is an exoplanet about 2.51 times Earth's width (a size estimated from its mass), 15 light-years away, orbiting closer to its star than the habitable zone we compute for it.
- Width
- 2.51 × Earth's estimated
- Mass
- 6.83 times Earth's measured
- One year
- 1.93778 days measured
- Distance from its star
- 0.0208066 AU from the Archive
- Temperature of a bare ball there
- 589 K computed, not measured
- Starlight, against Earth's
- 28.6 × computed
It was found by the back-and-forth wobble its pull puts into its star's motion, seen as a shift in the colour of the star's light in 2005. Its orbit is closer to its star than the habitable zone computed for it.
See GJ 876 d in 3D · The picture is an artist's impression.
GJ 876 c
GJ 876 c is an exoplanet about 14 times Earth's width (a size estimated from its mass), about 1.2 times Jupiter's, 15 light-years away, orbiting in its star's computed habitable zone.
- Width
- 14 × Earth's estimated
- Mass
- 226.985 times Earth's measured
- One year
- 30.0881 days measured
- Distance from its star
- 0.12959 AU from the Archive
- Temperature of a bare ball there
- 236 K computed, not measured
- Starlight, against Earth's
- 0.738 × computed
It was found by the back-and-forth wobble its pull puts into its star's motion, seen as a shift in the colour of the star's light in 2000. Its orbit lies inside the conservative habitable zone computed for its star (liquid water on a rocky world's surface would be possible there, which says nothing about whether any is).
See GJ 876 c in 3D · The picture is an artist's impression.
GJ 876 b
GJ 876 b is an exoplanet about 13.3 times Earth's width (a size estimated from its mass), about 1.2 times Jupiter's, 15 light-years away, orbiting in its star's computed habitable zone.
- Width
- 13.3 × Earth's estimated
- Mass
- 723.223 times Earth's measured
- One year
- 61.1166 days measured
- Distance from its star
- 0.208317 AU from the Archive
- Temperature of a bare ball there
- 186 K computed, not measured
- Starlight, against Earth's
- 0.286 × computed
It was found by the back-and-forth wobble its pull puts into its star's motion, seen as a shift in the colour of the star's light in 1998. Its orbit lies inside the conservative habitable zone computed for its star (liquid water on a rocky world's surface would be possible there, which says nothing about whether any is).
See GJ 876 b in 3D · The picture is an artist's impression.
GJ 876 e
GJ 876 e is an exoplanet about 3.92 times Earth's width (a size estimated from its mass), 15 light-years away, orbiting farther from its star than the habitable zone we compute for it.
- Width
- 3.92 × Earth's estimated
- Mass
- 14.6 times Earth's measured
- One year
- 124.26 days measured
- Distance from its star
- 0.3343 AU from the Archive
- Temperature of a bare ball there
- 147 K computed, not measured
- Starlight, against Earth's
- 0.111 × computed
It was found by the back-and-forth wobble its pull puts into its star's motion, seen as a shift in the colour of the star's light in 2010. Its orbit is farther from its star than the habitable zone computed for it.
See GJ 876 e in 3D · The picture is an artist's impression.
The star
- Surface temperature
- 3,294 K
- Width
- 0.3 × the Sun's
- Mass
- 0.32 × the Sun's
- Spectral type
- M2.5V
- Distance
- 15 light-years
- Habitable zone, computed
- 0.1156 to 0.2269 AU from the star