The HD 20781 System
HD 20781 is a planetary system in the constellation Fornax hosting 4 confirmed exoplanets around 2 stars, about 117 light-years from Earth.
Star HD 20781 and Its Habitable Zone
HD 20781
- Spectral type
- K0 V
- Surface temperature
- 5,256 K (Sun: 5,772 K)
- Mass
- 0.70 M☉
- Luminosity
- 0.4900 L☉
Habitable zone of HD 20781: 0.541–1.296 AU (conservative: 0.686–1.229 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
All 4 Planets in the HD 20781 System
| Planet | Type | Orbit | Radius | ESI | Discovered |
|---|---|---|---|---|---|
| HD 20781 b | Terrestrial | 5.3 d | — | 0.30 | 2019 |
| HD 20781 c | Super Earth | 14 d | — | 0.27 | 2019 |
| HD 20781 d | Neptune-like | 29 d | — | 0.26 | 2019 |
| HD 20781 e | Neptune-like | 86 d | — | 0.40 | 2019 |
Discovery History
The first planet found here, HD 20781 b, was discovered in 2019 using the radial velocity method.
- 2019 — HD 20781 b (Radial Velocity)
- 2019 — HD 20781 c (Radial Velocity)
- 2019 — HD 20781 d (Radial Velocity)
- 2019 — HD 20781 e (Radial Velocity)
Frequently Asked Questions About HD 20781
How many planets does HD 20781 have?
HD 20781 has 4 confirmed exoplanets distributed around its 2 stars. More may await discovery.
Are any planets in the HD 20781 system habitable?
None of the known planets in HD 20781 orbit within the star's habitable zone.
How far away is HD 20781?
HD 20781 is about 117 light-years from Earth in the constellation Fornax.
Explore the HD 20781 system in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
