The star
The star
TOI-5398
- Type
- G V
- Surface
- ≈ 6,000 K
- Size
- 1.05 × the Sun
- Mass
- 1.15 × the Sun
- Brightness
- 1.31 × the Sun
- Habitable zone
- 0.847–1.99 AU
The planets
TOI-5398
TOI-5398 c
- Year
- 4.77 days
- Distance from star
- 0.057 AU
- Mass
- 12 Earths
- Size
- 3.5 × Earth
- Temperature
- ≈ 1242 K (+969 °C)
- Found
- 2023, transit (Transiting Exoplanet Survey Satellite (TESS))
TOI-5398
TOI-5398 b
- Year
- 10.59 days
- Distance from star
- 0.098 AU
- Mass
- 59 Earths
- Size
- 10 × Earth
- Temperature
- ≈ 947 K (+674 °C)
- Found
- 2022, 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.