KELT-1 b
KELT-1 b is a hot Jupiter orbiting KELT-1 in the constellation Andromeda. It lies about 876 light-years from Earth and was discovered in 2012 using the transit method.
How Big Is KELT-1 b?
KELT-1 b has a radius of 12.44 times that of Earth, or 1.11 times the radius of Jupiter. Its mass is 8,654 times that of Earth, giving it a density of 24.70 g/cm³ — comparable to rocky planets like Earth (5.51 g/cm³).
Is KELT-1 b in the Habitable Zone?
KELT-1 b orbits inside the inner edge of the habitable zone of KELT-1. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of KELT-1: 1.344–3.120 AU (conservative: 1.703–2.958 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 KELT-1 b — one full orbit around KELT-1 — lasts just 29.2 hours, shorter than Mercury's 88-day year. It orbits at an average distance of 0.025 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.010).
How Was KELT-1 b Discovered?
KELT-1 b was discovered in 2012 using the transit method, with observations from KELT.
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-1 b?
KELT-1 b is 875.5 light-years (268.4 parsecs) from Earth. Light arriving here tonight left the planet around the year 1151. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 15,408,800 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-1 b scores 0.07, ranking #4,901 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: KELT-1
KELT-1
- Surface temperature
- 6,516 K (Sun: 5,772 K)
- Mass
- 1.34 M☉
- Radius
- 1.47 R☉
- Luminosity
- 3.5075 L☉
Planetary System
KELT-1 b is the only planet known to orbit KELT-1 so far.
KELT-1 b — Complete Data
| Radius | 12.442 Earth radii (1.110 Jupiter radii) |
|---|---|
| Mass | 8,654.15 Earth masses (27.230 Jupiter masses) |
| Density | 24.70 g/cm³ (Earth: 5.51) |
| Orbital period | 1.22 days |
| Orbital distance | 0.025 AU |
| Eccentricity | 0.010 |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 875.5 light-years (268.4 parsecs) |
| Constellation | Andromeda |
| Discovery method | Transit |
| Discovery facility | KELT |
| Discovery year | 2012 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About KELT-1 b
Is KELT-1 b habitable?
No — KELT-1 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is KELT-1 b?
KELT-1 b is about 876 light-years from Earth in the constellation Andromeda. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 15,408,800 years to get there.
How big is KELT-1 b compared to Earth?
KELT-1 b has 12.44 times the radius of Earth and about 8,654 times its mass.
How long is a year on KELT-1 b?
One orbit around KELT-1 takes 1.2 Earth days — short enough that 300 of its years would fit into one Earth year.
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