HATS-66 b
HATS-66 b is a hot Jupiter orbiting HATS-66 in the constellation Puppis. It lies about 4,821 light-years from Earth and was discovered in 2018 using the transit method.
How Big Is HATS-66 b?
HATS-66 b has a radius of 15.82 times that of Earth, or 1.41 times the radius of Jupiter. Its mass is 1,694 times that of Earth, giving it a density of 2.34 g/cm³ — between that of rocky and gaseous planets.
Is HATS-66 b in the Habitable Zone?
HATS-66 b orbits inside the inner edge of the habitable zone of HATS-66. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HATS-66: 1.725–3.998 AU (conservative: 2.185–3.790 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on HATS-66 b
The equilibrium temperature of HATS-66 b is about 1,998 K (1,725 °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 2,637 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on HATS-66 b — one full orbit around HATS-66 — lasts 3.14 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.047 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.06).
How Was HATS-66 b Discovered?
HATS-66 b was discovered in 2018 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-66 b?
HATS-66 b is 4,820.5 light-years (1,478.0 parsecs) from Earth. Light arriving here tonight left the planet about 4,821 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 84,840,800 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. HATS-66 b scores 0.06, ranking #5,184 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HATS-66
HATS-66
- Surface temperature
- 6,626 K (Sun: 5,772 K)
- Mass
- 1.41 M☉
- Radius
- 1.84 R☉
- Luminosity
- 5.8501 L☉
- Age
- 2.2 billion years (Sun: 4.6)
Planetary System
HATS-66 b is the only planet known to orbit HATS-66 so far.
HATS-66 b — Complete Data
| Radius | 15.816 Earth radii (1.411 Jupiter radii) |
|---|---|
| Mass | 1,694.03 Earth masses (5.330 Jupiter masses) |
| Density | 2.34 g/cm³ (Earth: 5.51) |
| Orbital period | 3.14 days |
| Orbital distance | 0.047 AU |
| Eccentricity | 0.064 |
| Equilibrium temperature | 1,998 K (1,725 °C) |
| Stellar irradiation | 2,637.00× Earth |
| Earth Similarity Index | 0.06 |
| Distance from Earth | 4,820.5 light-years (1,478.0 parsecs) |
| Constellation | Puppis |
| Discovery method | Transit |
| Discovery facility | HATSouth |
| Discovery year | 2018 |
Data: NASA Exoplanet Archive, last updated 2024-07-12. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HATS-66 b
Is HATS-66 b habitable?
No — HATS-66 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HATS-66 b?
HATS-66 b is about 4,821 light-years from Earth in the constellation Puppis. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 84,840,800 years to get there.
How big is HATS-66 b compared to Earth?
HATS-66 b has 15.82 times the radius of Earth and about 1,694 times its mass.
How long is a year on HATS-66 b?
One orbit around HATS-66 takes 3.1 Earth days — short enough that 116 of its years would fit into one Earth year.
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