Nearest neighbour
Ross 128
A quiet red dwarf 11 ly away with a temperate Earth-mass planet.
- Planets
- 1
- Distance
- 11.0 ly
- Host
- M-type
About Ross 128
Discovery
Ross 128 b was discovered in 2017 by Bonfils and colleagues using HARPS radial velocities — a temperate, roughly Earth-mass planet around an unusually quiet M4 red dwarf 11 light-years away.
Why it matters
Ross 128 is one of the quietest M-dwarfs known — virtually no flaring — which makes its planet a more promising habitability candidate than analogues around violent red dwarfs like Proxima Centauri.
Current research
Because the system is non-transiting, atmospheric characterization is impossible with current methods; Ross 128 b waits for direct-imaging-capable future instruments.
Comparable to
An Earth-mass world only 11 light-years away, orbiting a red dwarf so calm that its planet might actually keep its atmosphere.
System geometry
At a glance
- Hostname
- Ross 128
- Spectral type
- M4
- Distance
- 11.0 ly · 3.37 pc
- Stellar mass
- 0.17 M☉
- Stellar radius
- 0.20 R☉
- Luminosity
- 3.62e-3 L☉
- Effective temp
- 3192 K
- Confirmed planets
- 1
- Habitable zone
- 0.057 – 0.082 AU
Top-down orbital diagram
Orbits to scale within this system. Dashed green = habitable-zone edges.
Planet positions are illustrative (evenly spaced in phase). For live motion see the 3D scene.
The planets
1 confirmed.
Rocky world
Ross 128 b
- Orbit
- 0.050 AU
- Period
- 9.87 days
- Radius
- 1.11 R⊕
- Mass
- 1.40 M⊕
- Eq. temperature
- 301 K
- Eccentricity
- 0.116
- Discovered
- 2017 · Radial Velocity
Compared to our Solar System
Each row shows the closest Solar-System analog by radius (log-space). Earth is pinned at the bottom as the constant frame of reference.
| Planet | Radius (R⊕) | Mass (M⊕) | Orbit (AU) | Period (days) | Eq temp (K) | Solar analog |
|---|---|---|---|---|---|---|
| Ross 128 b | 1.11 | 1.40 | 0.050 | 9.87 | 301 | Earth |
| Earth (reference) | 1.00 | 1.00 | 1.000 | 365.25 | 255 | — |
Research status
◇ JWST observation status
No JWST programs are currently targeting planets in this system. The system may be observed in future cycles or by upcoming missions (Ariel, HWO, Roman).
Discovery timeline
- 2017
Ross 128 b
via Radial Velocity
If you liked this
Other systems in the same theme:
Barnard's Star
4 planets · 6.0 ly · M3.5-4 V
Second-closest star system; planet candidates announced 2024 after decades of false starts.
Tau Ceti
3 planets · 11.8 ly · G8.5V
Sun-like star 12 ly away — three confirmed planets, with the outermost (h) in the habitable zone.
Wolf 1061
3 planets · 14.0 ly · M3.5
14 ly away — three planets, the middle one in the habitable zone.
Related reading
Articles mentioning Ross 128:
Experience it
See Ross 128 in interactive 3D
Fly through the system, click any planet, watch orbits play out at 100× speed.
▶ Launch 3D scene