TOI-1227 b
TOI-1227 b is a cold gas giant orbiting the M4.5V-M5V star TOI-1227 in the constellation Musca. It lies about 328 light-years from Earth and was discovered in 2022 using the transit method. It orbits within the habitable zone of its star — the region where liquid water could exist on a planet's surface.
How Big Is TOI-1227 b?
TOI-1227 b has a radius of 9.57 times that of Earth, or 0.85 times the radius of Jupiter.
Is TOI-1227 b in the Habitable Zone?
TOI-1227 b orbits inside the conservative habitable zone of TOI-1227 — the region where a rocky planet could sustain liquid water on its surface. This makes it one of the most interesting known exoplanets in the search for life.
Habitable zone of TOI-1227: 0.041–0.109 AU (conservative: 0.052–0.103 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on TOI-1227 b
TOI-1227 b receives 3.21 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on TOI-1227 b — one full orbit around TOI-1227 — lasts 27.4 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.089 AU — closer to its star than Mercury is to the Sun.
How Was TOI-1227 b Discovered?
TOI-1227 b was discovered in 2022 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-1227 b?
TOI-1227 b is 328.2 light-years (100.6 parsecs) from Earth. Light arriving here tonight left the planet around the year 1698. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 5,776,320 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-1227 b scores 0.32, ranking #1,009 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-1227
TOI-1227
- Spectral type
- M4.5V-M5V
- Surface temperature
- 3,072 K (Sun: 5,772 K)
- Mass
- 0.17 M☉
- Radius
- 0.56 R☉
- Luminosity
- 0.0025 L☉
- Age
- 0.0 billion years (Sun: 4.6)
Planetary System
TOI-1227 b is the only planet known to orbit TOI-1227 so far.
TOI-1227 b — Complete Data
| Radius | 9.572 Earth radii (0.854 Jupiter radii) |
|---|---|
| Orbital period | 27.36 days |
| Orbital distance | 0.089 AU |
| Stellar irradiation | 3.21× Earth |
| Earth Similarity Index | 0.32 |
| Distance from Earth | 328.2 light-years (100.6 parsecs) |
| Constellation | Musca |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2022 |
Data: NASA Exoplanet Archive, last updated 2022-03-28. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-1227 b
Is TOI-1227 b habitable?
TOI-1227 b orbits within the habitable zone of TOI-1227, the region where liquid water could exist on a planet's surface. It sits in the conservative habitable zone — the most promising region for habitability. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.
How far away is TOI-1227 b?
TOI-1227 b is about 328 light-years from Earth in the constellation Musca. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 5,776,320 years to get there.
How big is TOI-1227 b compared to Earth?
TOI-1227 b has 9.57 times the radius of Earth.
How long is a year on TOI-1227 b?
One orbit around TOI-1227 takes 27.4 Earth days — short enough that 13 of its years would fit into one Earth year.
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