HD 80606 planetary system
HD 80606 is a Sun-like main-sequence star of spectral type G5 approximately 217 light-years from Earth (66.47 parsecs). It hosts 1 confirmed exoplanet. 1 planet transits the host star from our line of sight, allowing direct measurements of size and atmosphere.
Host star
- Name
- HD 80606
- Spectral type
- G5
- Effective temperature
- 5,565 K
- Mass
- 1.05 M☉ (solar masses)
- Radius
- 1.05 R☉ (solar radii)
- Distance
- 66.47 pc (217 ly)
- Hipparcos catalog
- HIP 45982
Confirmed planets (1)
| Planet | Class | Mass (M⊕) | Radius (R⊕) | Period (d) | Distance (AU) | Eq. temp (K) | Discovered |
|---|---|---|---|---|---|---|---|
| HD 80606 b | Neptune-like | 1323.47 | 11.57 | 111.44 | 0.4603 | 405 | 2001 |
The planets in detail
HD 80606 b is a Neptune-like world with about 11.57 Earth radii and 1323.47 Earth masses. It orbits HD 80606 at 0.4603 AU with a 111-day year, and a warm equilibrium temperature of 405 K. The planet transits its host star, which is how its radius and (when combined with mass) bulk density are pinned down. Its orbit is notably eccentric (e = 0.93), meaning the distance to its star — and the irradiation it receives — varies substantially over each year. It was confirmed in 2001 via radial velocity (Doppler) measurements.
Discovery
The single planet in the HD 80606 system was confirmed in 2001 using radial velocity (Doppler) measurements. Detection facilities: Multiple Observatories.
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 140.6570°, declination 50.6038°. Because 1 planet transits from our perspective, advanced amateurs with photometric setups can sometimes detect the resulting brightness dips. 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.
