TOI-954 b
TOI-954 b is a hot Jupiter orbiting TOI-954 in the constellation Eridanus. It lies about 779 light-years from Earth and was discovered in 2020 using the transit method.
How Big Is TOI-954 b?
TOI-954 b has a radius of 9.55 times that of Earth, or 0.85 times the radius of Jupiter. Its mass is 55.3 times that of Earth, giving it a density of 0.35 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is TOI-954 b in the Habitable Zone?
TOI-954 b orbits inside the inner edge of the habitable zone of TOI-954. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-954: 1.396–3.294 AU (conservative: 1.768–3.123 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-954 b
The equilibrium temperature of TOI-954 b is about 1,526 K (1,253 °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 1,393 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-954 b — one full orbit around TOI-954 — lasts 3.68 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.050 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.14).
How Was TOI-954 b Discovered?
TOI-954 b was discovered in 2020 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-954 b?
TOI-954 b is 778.8 light-years (238.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1248. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 13,706,880 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-954 b scores 0.09, ranking #4,515 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-954
TOI-954
- Surface temperature
- 5,710 K (Sun: 5,772 K)
- Mass
- 1.20 M☉
- Radius
- 1.89 R☉
- Luminosity
- 3.4300 L☉
- Age
- 6.1 billion years (Sun: 4.6)
Planetary System
TOI-954 b is the only planet known to orbit TOI-954 so far.
TOI-954 b — Complete Data
| Radius | 9.550 Earth radii (0.852 Jupiter radii) |
|---|---|
| Mass | 55.30 Earth masses (0.174 Jupiter masses) |
| Density | 0.35 g/cm³ (Earth: 5.51) |
| Orbital period | 3.68 days |
| Orbital distance | 0.050 AU |
| Eccentricity | 0.140 |
| Equilibrium temperature | 1,526 K (1,253 °C) |
| Stellar irradiation | 1,393.00× Earth |
| Earth Similarity Index | 0.09 |
| Distance from Earth | 778.8 light-years (238.8 parsecs) |
| Constellation | Eridanus |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2020 |
Data: NASA Exoplanet Archive, last updated 2020-11-13. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-954 b
Is TOI-954 b habitable?
No — TOI-954 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-954 b?
TOI-954 b is about 779 light-years from Earth in the constellation Eridanus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 13,706,880 years to get there.
How big is TOI-954 b compared to Earth?
TOI-954 b has 9.55 times the radius of Earth and about 55.3 times its mass.
How long is a year on TOI-954 b?
One orbit around TOI-954 takes 3.7 Earth days — short enough that 99 of its years would fit into one Earth year.
Explore TOI-954 b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
