The star
The star
HIP 99770
- Type
- A5-A6
- Surface
- ≈ 8,000 K
- Size
- 1.94 × the Sun
- Mass
- 1.90 × the Sun
- Brightness
- 13.9 × the Sun
- Habitable zone
- 3.54–6.22 AU
The planets
HIP 99770
HIP 99770 b
- Year
- 50.9 years
- Distance from star
- 15.8 AU
- Mass
- 17 Jupiters
- Size
- 12 × Earth
- Temperature
- ≈ 135 K (-138 °C)
- Found
- 2023, imaging (Multiple Observatories)
Masses found by the wobble method are minimums, because the orbit's tilt is unknown. Temperatures are equilibrium estimates for a bare planet, before any atmosphere.
How we know
A direct picture
The star's glare is blocked or subtracted, leaving the planet's own faint light as a dot that moves along its orbit over the years.
Sources
- Planet and star parameters: NASA Exoplanet Archive, Planetary Systems Composite Parameters, retrieved 1 Nov 2026. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with NASA under the Exoplanet Exploration Program.
- Position: HYG Database v4.1 (CC BY-SA 4.0).
- Habitable zone: a simple estimate from the star's brightness (√L × 0.95 to 1.67 AU), shown as a guide.