HATS-12 b
HATS-12 b is a hot Jupiter orbiting HATS-12 in the constellation Sagittarius. It lies about 2,434 light-years from Earth and was discovered in 2016 using the transit method.
How Big Is HATS-12 b?
HATS-12 b has a radius of 7.76 times that of Earth, or 0.69 times the radius of Jupiter.
Is HATS-12 b in the Habitable Zone?
HATS-12 b orbits inside the inner edge of the habitable zone of HATS-12. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HATS-12: 1.026–2.387 AU (conservative: 1.300–2.263 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on HATS-12 b
The equilibrium temperature of HATS-12 b is about 1,446 K (1,173 °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.
Orbit and Year Length
A year on HATS-12 b — one full orbit around HATS-12 — lasts 3.14 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.044 AU — closer to its star than Mercury is to the Sun.
How Was HATS-12 b Discovered?
HATS-12 b was discovered in 2016 using the transit method, with observations from HATSouth.
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 HATS-12 b?
HATS-12 b is 2,433.6 light-years (746.1 parsecs) from Earth. Light arriving here tonight left the planet about 2,434 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 42,831,360 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. HATS-12 b scores 0.11, ranking #4,390 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HATS-12
HATS-12
- Surface temperature
- 6,357 K (Sun: 5,772 K)
- Mass
- 1.16 M☉
- Radius
- 1.17 R☉
Planetary System
HATS-12 b is the only planet known to orbit HATS-12 so far.
HATS-12 b — Complete Data
| Radius | 7.760 Earth radii (0.692 Jupiter radii) |
|---|---|
| Orbital period | 3.14 days |
| Orbital distance | 0.044 AU |
| Equilibrium temperature | 1,446 K (1,173 °C) |
| Earth Similarity Index | 0.11 |
| Distance from Earth | 2,433.6 light-years (746.1 parsecs) |
| Constellation | Sagittarius |
| Discovery method | Transit |
| Discovery facility | HATSouth |
| Discovery year | 2016 |
Data: NASA Exoplanet Archive, last updated 2018-10-24. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HATS-12 b
Is HATS-12 b habitable?
No — HATS-12 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HATS-12 b?
HATS-12 b is about 2,434 light-years from Earth in the constellation Sagittarius. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 42,831,360 years to get there.
How big is HATS-12 b compared to Earth?
HATS-12 b has 7.76 times the radius of Earth.
How long is a year on HATS-12 b?
One orbit around HATS-12 takes 3.1 Earth days — short enough that 116 of its years would fit into one Earth year.
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