HD 192310 b
HD 192310 b is a Neptune-like planet orbiting HD 192310 in the constellation Capricornus. It lies about 29 light-years from Earth and was discovered in 2011 using the radial velocity method.
Is HD 192310 b in the Habitable Zone?
HD 192310 b orbits inside the inner edge of the habitable zone of HD 192310. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 192310: 0.482–1.158 AU (conservative: 0.611–1.098 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on HD 192310 b
The equilibrium temperature of HD 192310 b is about 355 K (82 °C) — hotter than anywhere on Earth. 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 HD 192310 b — one full orbit around HD 192310 — lasts 74.7 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.320 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.13).
How Was HD 192310 b Discovered?
HD 192310 b was discovered in 2011 using the radial velocity method, with observations from La Silla Observatory.
The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.
How Far Away Is HD 192310 b?
HD 192310 b is 28.7 light-years (8.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1998. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 505,120 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. HD 192310 b scores 0.40, ranking #476 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 192310
HD 192310
- Surface temperature
- 5,166 K (Sun: 5,772 K)
- Mass
- 0.80 M☉
- Luminosity
- 0.3850 L☉
- Age
- 7.8 billion years (Sun: 4.6)
The HD 192310 Planetary System
HD 192310 b is one of 2 known planets in the HD 192310 system. Its siblings:
- HD 192310 c (Neptune-like)
HD 192310 b — Complete Data
| Mass (best estimate) | 16.90 Earth masses |
|---|---|
| Orbital period | 74.72 days |
| Orbital distance | 0.320 AU |
| Eccentricity | 0.130 |
| Equilibrium temperature | 355 K (82 °C) |
| Earth Similarity Index | 0.40 |
| Distance from Earth | 28.7 light-years (8.8 parsecs) |
| Constellation | Capricornus |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2011 |
Data: NASA Exoplanet Archive, last updated 2015-07-01. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 192310 b
Is HD 192310 b habitable?
No — HD 192310 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 192310 b?
HD 192310 b is about 29 light-years from Earth in the constellation Capricornus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 505,120 years to get there.
How long is a year on HD 192310 b?
One orbit around HD 192310 takes 74.7 Earth days.
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