GJ 581 planetary system
GJ 581 is a cool red dwarf of spectral type M3.0 V approximately 20.5 light-years from Earth (6.30 parsecs). It hosts 3 confirmed exoplanets.
Host star
- Name
- GJ 581
- Spectral type
- M3.0 V
- Effective temperature
- 3,500 K
- Mass
- 0.29 M☉ (solar masses)
- Radius
- 0.30 R☉ (solar radii)
- Distance
- 6.30 pc (20.5 ly)
- Hipparcos catalog
- HIP 74995
Confirmed planets (3)
| Planet | Class | Mass (M⊕) | Radius (R⊕) | Period (d) | Distance (AU) | Eq. temp (K) | Discovered |
|---|---|---|---|---|---|---|---|
| GJ 581 e | Super-Earth | 2.48 | 1.38 | 3.15 | 0.0280 | — | 2009 |
| GJ 581 b | Mini-Neptune | 20.50 | 4.79 | 5.37 | 0.0399 | — | 2005 |
| GJ 581 c | Mini-Neptune | 6.81 | 2.50 | 12.92 | 0.0718 | — | 2007 |
The planets in detail
GJ 581 e is a Super-Earth with about 1.38 Earth radii and 2.48 Earth masses. It orbits GJ 581 at 0.0280 AU with a 3.1-day year, and no published equilibrium temperature. It was confirmed in 2009 via radial velocity (Doppler) measurements.
GJ 581 b is a Mini-Neptune with about 4.79 Earth radii and 20.50 Earth masses. It orbits GJ 581 at 0.0399 AU with a 5.4-day year, and no published equilibrium temperature. It was confirmed in 2005 via radial velocity (Doppler) measurements.
GJ 581 c is a Mini-Neptune with about 2.50 Earth radii and 6.81 Earth masses. It orbits GJ 581 at 0.0718 AU with a 12.9-day year, and no published equilibrium temperature. It was confirmed in 2007 via radial velocity (Doppler) measurements.
Discovery
The GJ 581 system was first identified in 2005, with confirmation work continuing through 2009 using radial velocity (Doppler) measurements. Detection facilities: La Silla Observatory.
Observing from Earth
Exoplanets cannot be resolved visually with amateur telescopes — the host star's glare is overwhelming and even space-based direct imaging requires sophisticated coronagraphs. What you can observe is the host star itself at right ascension 229.8565°, declination -7.7227°. Use the 3D orrery above to inspect orbital geometry, planetary scale, and the habitable-zone overlay — the orbits are computed from the published Keplerian elements and animate at user-controlled time rates.
