KELT-24 b
KELT-24 b is a hot Jupiter orbiting KELT-24 in the constellation Ursa Major. It lies about 315 light-years from Earth and was discovered in 2019 using the transit method.
How Big Is KELT-24 b?
KELT-24 b has a radius of 12.71 times that of Earth, or 1.13 times the radius of Jupiter. Its mass is 1,459 times that of Earth, giving it a density of 3.90 g/cm³ — between that of rocky and gaseous planets.
Is KELT-24 b in the Habitable Zone?
KELT-24 b orbits inside the inner edge of the habitable zone of KELT-24. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of KELT-24: 1.197–2.781 AU (conservative: 1.516–2.637 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on KELT-24 b
The equilibrium temperature of KELT-24 b is about 1,391 K (1,118 °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 624 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on KELT-24 b — one full orbit around KELT-24 — lasts 5.55 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.067 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.032).
How Was KELT-24 b Discovered?
KELT-24 b was discovered in 2019 using the transit method, with observations from KELT-North.
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 KELT-24 b?
KELT-24 b is 314.8 light-years (96.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1712. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 5,540,480 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. KELT-24 b scores 0.06, ranking #5,064 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: KELT-24
KELT-24 b belongs to a system of 2 stars; it orbits KELT-24.
KELT-24
- Surface temperature
- 6,426 K (Sun: 5,772 K)
- Mass
- 1.27 M☉
- Radius
- 1.34 R☉
- Luminosity
- 2.7500 L☉
- Age
- 2.0 billion years (Sun: 4.6)
Planetary System
KELT-24 b is the only planet known to orbit KELT-24 so far.
KELT-24 b — Complete Data
| Radius | 12.711 Earth radii (1.134 Jupiter radii) |
|---|---|
| Mass | 1,458.83 Earth masses (4.590 Jupiter masses) |
| Density | 3.90 g/cm³ (Earth: 5.51) |
| Orbital period | 5.55 days |
| Orbital distance | 0.067 AU |
| Eccentricity | 0.032 |
| Equilibrium temperature | 1,391 K (1,118 °C) |
| Stellar irradiation | 624.00× Earth |
| Earth Similarity Index | 0.06 |
| Distance from Earth | 314.8 light-years (96.5 parsecs) |
| Constellation | Ursa Major |
| Discovery method | Transit |
| Discovery facility | KELT-North |
| Discovery year | 2019 |
Data: NASA Exoplanet Archive, last updated 2024-08-29. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About KELT-24 b
Is KELT-24 b habitable?
No — KELT-24 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is KELT-24 b?
KELT-24 b is about 315 light-years from Earth in the constellation Ursa Major. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 5,540,480 years to get there.
How big is KELT-24 b compared to Earth?
KELT-24 b has 12.71 times the radius of Earth and about 1,459 times its mass.
How long is a year on KELT-24 b?
One orbit around KELT-24 takes 5.6 Earth days — short enough that 66 of its years would fit into one Earth year.
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