The star
The star
TOI-561
- Type
- G9 V
- Surface
- ≈ 5,342 K
- Size
- 0.84 × the Sun
- Mass
- 0.81 × the Sun
- Brightness
- 0.522 × the Sun
- Habitable zone
- 0.556–1.33 AU
The planets
TOI-561
TOI-561 b
- Year
- 0.45 days
- Distance from star
- 0.0106 AU
- Mass
- 2 Earths
- Size
- 1.4 × Earth
- Temperature
- ≈ 2319 K (+2046 °C)
- Found
- 2020, transit (Transiting Exoplanet Survey Satellite (TESS))
TOI-561
TOI-561 c
- Year
- 10.78 days
- Distance from star
- 0.0889 AU
- Mass
- 5.9 Earths
- Size
- 2.9 × Earth
- Temperature
- ≈ 802 K (+529 °C)
- Found
- 2020, transit (Transiting Exoplanet Survey Satellite (TESS))
TOI-561
TOI-561 d
- Year
- 25.71 days
- Distance from star
- 0.159 AU
- Mass
- 13 Earths
- Size
- 2.6 × Earth
- Temperature
- ≈ 600 K (+327 °C)
- Found
- 2020, transit (Transiting Exoplanet Survey Satellite (TESS))
TOI-561
TOI-561 e
- Year
- 77.14 days
- Distance from star
- 0.33 AU
- Mass
- 12 Earths
- Size
- 2.5 × Earth
- Temperature
- ≈ 416 K (+143 °C)
- Found
- 2020, 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.