The star
The star
TOI-1221
- Type
- yellow star
- Surface
- ≈ 5,592 K
- Size
- 1.03 × the Sun
- Mass
- 0.93 × the Sun
- Brightness
- 0.962 × the Sun
- Habitable zone
- 0.744–1.76 AU
The planets
TOI-1221
TOI-1221 b
- Year
- 91.68 days
- Distance from star
- 0.387 AU
- Mass
- 3.5 Jupiters
- Size
- 2.9 × Earth
- Temperature
- ≈ 440 K (+167 °C)
- Found
- 2023, transit (Transiting Exoplanet Survey Satellite (TESS))
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.