HD 99706 is 478 light-years from the Sun. The NASA Exoplanet Archive lists 2 planets around this K0 star; the first was found in 2011 by radial velocity (W. M. Keck Observatory).
Fly there in 3DHD 99706 c takes 3.5 years to go round its star once.
Where the archive gives only a period or only an orbit size, the other is worked out from Kepler’s third law with the star’s mass.
| Spectral type | K0 |
| Surface temperature | 4,862 K |
| Mass | 1.46 solar masses |
| Radius | 5.52 solar radii |
| Luminosity | 15.4 times the Sun |
| Apparent magnitude | 7.65 |
| Age | about 2.1 billion years |
| Distance from the Sun | 478.1 light-years (146.6 parsecs) |
| Position (J2000) | RA 172.1262°, Dec 43.9662° |
| Constellation | Ursa Major |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| HD 99706 c | 3.5 years | 2.615 AU from Kepler’s law | 12.8 R⊕ estimated | 1808.5 M⊕ minimum | Radial Velocity, 2016 |
| HD 99706 b | 841.0 days | 1.980 AU | 13.7 R⊕ estimated | 390.93 M⊕ minimum | Radial Velocity, 2011 |
Values are the NASA Exoplanet Archive’s composite parameters. A radius marked estimated comes from a mass–radius relation; a mass marked minimum is M sin i. Planet sizes and colours in the 3D view are renderings: none of these worlds has been photographed as more than a point of light.
For a star of 4,862 K, 15 times as bright as the Sun, the habitable zone, where starlight could keep water liquid on a rocky surface, runs from about 3.92 to 7.13 AU. None of its known planets orbits inside it. The zone says how much starlight arrives, not whether a planet has water or air. The edges follow Kopparapu et al. (2014), as the 3D view draws them.
The light you see left 478 years ago, around 1550.