24 Boo b
24 Boo b is a cold gas giant orbiting the G3 IV star 24 Boo in the constellation Boötes. It lies about 313 light-years from Earth and was discovered in 2018 using the radial velocity method.
Is 24 Boo b in the Habitable Zone?
24 Boo b orbits inside the inner edge of the habitable zone of 24 Boo. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of 24 Boo: 6.855–16.699 AU (conservative: 8.683–15.833 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 ›
Orbit and Year Length
A year on 24 Boo b — one full orbit around 24 Boo — lasts 30.3 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.194 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.032).
How Was 24 Boo b Discovered?
24 Boo b was discovered in 2018 using the radial velocity method, with observations from Okayama Astrophysical Observatory.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is 24 Boo b?
24 Boo b is 313.1 light-years (96.0 parsecs) from Earth. Light arriving here tonight left the planet around the year 1713. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 5,510,560 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. 24 Boo b scores 0.07, ranking #5,050 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: 24 Boo
24 Boo
- Spectral type
- G3 IV
- Surface temperature
- 4,816 K (Sun: 5,772 K)
- Mass
- 1.05 M☉
- Radius
- 12.19 R☉
- Luminosity
- 75.3199 L☉
Planetary System
24 Boo b is the only planet known to orbit 24 Boo so far.
24 Boo b — Complete Data
| Mass (best estimate) | 280.64 Earth masses |
|---|---|
| Orbital period | 30.33 days |
| Orbital distance | 0.194 AU |
| Eccentricity | 0.032 |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 313.1 light-years (96.0 parsecs) |
| Constellation | Boötes |
| Discovery method | Radial Velocity |
| Discovery facility | Okayama Astrophysical Observatory |
| Discovery year | 2018 |
Data: NASA Exoplanet Archive, last updated 2023-09-19. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About 24 Boo b
Is 24 Boo b habitable?
No — 24 Boo b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is 24 Boo b?
24 Boo b is about 313 light-years from Earth in the constellation Boötes. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 5,510,560 years to get there.
How long is a year on 24 Boo b?
One orbit around 24 Boo takes 30.3 Earth days — short enough that 12 of its years would fit into one Earth year.
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