EPIC 246851721 b
EPIC 246851721 b is a hot Jupiter orbiting the F5 V star EPIC 246851721 in the constellation Taurus. It lies about 1,215 light-years from Earth and was discovered in 2018 using the transit method.
How Big Is EPIC 246851721 b?
EPIC 246851721 b has a radius of 11.78 times that of Earth, or 1.05 times the radius of Jupiter. Its mass is 953 times that of Earth, giving it a density of 3.10 g/cm³ — between that of rocky and gaseous planets.
Is EPIC 246851721 b in the Habitable Zone?
EPIC 246851721 b orbits inside the inner edge of the habitable zone of EPIC 246851721. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of EPIC 246851721: 1.341–3.128 AU (conservative: 1.698–2.965 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 EPIC 246851721 b
The equilibrium temperature of EPIC 246851721 b is about 1,401 K (1,128 °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 642 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on EPIC 246851721 b — one full orbit around EPIC 246851721 — lasts 6.18 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.072 AU — closer to its star than Mercury is to the Sun.
How Was EPIC 246851721 b Discovered?
EPIC 246851721 b was discovered in 2018 using the transit method, with observations from K2.
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 EPIC 246851721 b?
EPIC 246851721 b is 1,215.4 light-years (372.6 parsecs) from Earth. Light arriving here tonight left the planet about 1,215 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 21,391,040 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. EPIC 246851721 b scores 0.08, ranking #4,751 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: EPIC 246851721
EPIC 246851721 b belongs to a system of 2 stars; it orbits EPIC 246851721.
EPIC 246851721
- Spectral type
- F5 V
- Surface temperature
- 6,202 K (Sun: 5,772 K)
- Mass
- 1.32 M☉
- Radius
- 1.59 R☉
- Luminosity
- 3.3600 L☉
- Age
- 3.0 billion years (Sun: 4.6)
Planetary System
EPIC 246851721 b is the only planet known to orbit EPIC 246851721 so far.
EPIC 246851721 b — Complete Data
| Radius | 11.781 Earth radii (1.051 Jupiter radii) |
|---|---|
| Mass | 953.49 Earth masses (3.000 Jupiter masses) |
| Density | 3.10 g/cm³ (Earth: 5.51) |
| Orbital period | 6.18 days |
| Orbital distance | 0.072 AU |
| Equilibrium temperature | 1,401 K (1,128 °C) |
| Stellar irradiation | 642.00× Earth |
| Earth Similarity Index | 0.08 |
| Distance from Earth | 1,215.4 light-years (372.6 parsecs) |
| Constellation | Taurus |
| Discovery method | Transit |
| Discovery facility | K2 |
| Discovery year | 2018 |
Data: NASA Exoplanet Archive, last updated 2019-12-02. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About EPIC 246851721 b
Is EPIC 246851721 b habitable?
No — EPIC 246851721 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is EPIC 246851721 b?
EPIC 246851721 b is about 1,215 light-years from Earth in the constellation Taurus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 21,391,040 years to get there.
How big is EPIC 246851721 b compared to Earth?
EPIC 246851721 b has 11.78 times the radius of Earth and about 953 times its mass.
How long is a year on EPIC 246851721 b?
One orbit around EPIC 246851721 takes 6.2 Earth days — short enough that 59 of its years would fit into one Earth year.
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