TOI-4010 b
TOI-4010 b is a sub-Neptune orbiting the K V star TOI-4010 in the constellation Cassiopeia. It lies about 579 light-years from Earth and was discovered in 2023 using the transit method.
How Big Is TOI-4010 b?
TOI-4010 b has a radius of 3.02 times that of Earth. Its mass is 11.0 times that of Earth, giving it a density of 2.20 g/cm³ — between that of rocky and gaseous planets.
Is TOI-4010 b in the Habitable Zone?
TOI-4010 b orbits inside the inner edge of the habitable zone of TOI-4010. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-4010: 0.480–1.162 AU (conservative: 0.608–1.102 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Temperature on TOI-4010 b
The equilibrium temperature of TOI-4010 b is about 1,441 K (1,168 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C. It receives 714 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-4010 b — one full orbit around TOI-4010 — lasts just 32.4 hours, shorter than Mercury's 88-day year. It orbits at an average distance of 0.023 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.030).
How Was TOI-4010 b Discovered?
TOI-4010 b was discovered in 2023 using the transit method, with observations from Transiting Exoplanet Survey Satellite (TESS).
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is TOI-4010 b?
TOI-4010 b is 578.9 light-years (177.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1448. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 10,188,640 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. TOI-4010 b scores 0.21, ranking #3,768 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-4010
TOI-4010
- Spectral type
- K V
- Surface temperature
- 4,960 K (Sun: 5,772 K)
- Mass
- 0.88 M☉
- Radius
- 0.83 R☉
- Age
- 6.1 billion years (Sun: 4.6)
The TOI-4010 Planetary System
TOI-4010 b is one of 4 known planets in the TOI-4010 system. Its siblings:
- TOI-4010 c (Neptune-like)
- TOI-4010 d (Cold Gas Giant)
- TOI-4010 e (Cold Gas Giant)
TOI-4010 b — Complete Data
| Radius | 3.020 Earth radii (0.269 Jupiter radii) |
|---|---|
| Mass | 11.00 Earth masses (0.035 Jupiter masses) |
| Density | 2.20 g/cm³ (Earth: 5.51) |
| Orbital period | 1.35 days |
| Orbital distance | 0.023 AU |
| Eccentricity | 0.030 |
| Equilibrium temperature | 1,441 K (1,168 °C) |
| Stellar irradiation | 714.00× Earth |
| Earth Similarity Index | 0.21 |
| Distance from Earth | 578.9 light-years (177.5 parsecs) |
| Constellation | Cassiopeia |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2023 |
Data: NASA Exoplanet Archive, last updated 2023-06-27. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-4010 b
Is TOI-4010 b habitable?
No — TOI-4010 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-4010 b?
TOI-4010 b is about 579 light-years from Earth in the constellation Cassiopeia. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 10,188,640 years to get there.
How big is TOI-4010 b compared to Earth?
TOI-4010 b has 3.02 times the radius of Earth and about 11.0 times its mass.
How long is a year on TOI-4010 b?
One orbit around TOI-4010 takes 1.3 Earth days — short enough that 271 of its years would fit into one Earth year.
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