HD 174205 b
HD 174205 b is a cold gas giant orbiting the K2 star HD 174205 in the constellation Draco. It lies about 763 light-years from Earth and was discovered in 2022 using the radial velocity method.
Is HD 174205 b in the Habitable Zone?
HD 174205 b orbits inside the inner edge of the habitable zone of HD 174205. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 174205: 12.440–31.014 AU (conservative: 15.757–29.404 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Orbit and Year Length
A year on HD 174205 b — one full orbit around HD 174205 — lasts 582.0 Earth days, longer than an Earth year. It orbits at an average distance of 1.700 AU. Its orbit is highly elliptical (eccentricity 0.40), swinging dramatically closer to and farther from its star.
How Was HD 174205 b Discovered?
HD 174205 b was discovered in 2022 using the radial velocity method, with observations from Bohyunsan Optical Astronomical 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 174205 b?
HD 174205 b is 763.3 light-years (234.0 parsecs) from Earth. Light arriving here tonight left the planet around the year 1263. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 13,434,080 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 174205 b scores 0.08, ranking #4,657 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 174205
HD 174205
- Spectral type
- K2
- Surface temperature
- 4,308 K (Sun: 5,772 K)
- Mass
- 1.80 M☉
- Radius
- 26.60 R☉
- Luminosity
- 239.0012 L☉
- Age
- 1.7 billion years (Sun: 4.6)
Planetary System
HD 174205 b is the only planet known to orbit HD 174205 so far.
HD 174205 b — Complete Data
| Mass (best estimate) | 1,334.88 Earth masses |
|---|---|
| Orbital period | 582.00 days |
| Orbital distance | 1.700 AU |
| Eccentricity | 0.400 |
| Earth Similarity Index | 0.08 |
| Distance from Earth | 763.3 light-years (234.0 parsecs) |
| Constellation | Draco |
| Discovery method | Radial Velocity |
| Discovery facility | Bohyunsan Optical Astronomical Observatory |
| Discovery year | 2022 |
Data: NASA Exoplanet Archive, last updated 2022-06-27. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 174205 b
Is HD 174205 b habitable?
No — HD 174205 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 174205 b?
HD 174205 b is about 763 light-years from Earth in the constellation Draco. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 13,434,080 years to get there.
How long is a year on HD 174205 b?
One orbit around HD 174205 takes 582.0 Earth days.
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