The star
The star
Kepler-1321
- Type
- orange dwarf
- Surface
- ≈ 4,094 K
- Size
- 0.53 × the Sun
- Mass
- 0.54 × the Sun
- Brightness
- 0.137 × the Sun
- Habitable zone
- 0.3–0.755 AU
The planets
Kepler-1321
Kepler-1321 c
- Year
- 2.23 days
- Distance from star
- 0.0267 AU
- Mass
- 6.3 Earths
- Size
- 2.4 × Earth
- Temperature
- ≈ 697 K (+424 °C)
- Found
- 2016, transit (Kepler)
Kepler-1321
Kepler-1321 d
- Year
- 5.72 days
- Distance from star
- 0.0501 AU
- Mass
- 7.4 Earths
- Size
- 2.6 × Earth
- Temperature
- ≈ 509 K (+236 °C)
- Found
- 2021, transit (Kepler)
Kepler-1321
Kepler-1321 b
- Year
- 11.13 days
- Distance from star
- 0.0781 AU
- Mass
- 22 Earths
- Size
- 4.9 × Earth
- Temperature
- ≈ 408 K (+135 °C)
- Found
- 2016, transit (Kepler)
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
The shadow
The planet passes in front of its star and dims it by a fraction of a percent, every orbit. The dip gives the planet's size and year.
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.