HD 139357 b
HD 139357 b is a exoplanet orbiting HD 139357 in the constellation Draco. It lies about 366 light-years from Earth and was discovered in 2008 using the radial velocity method.
Is HD 139357 b in the Habitable Zone?
The position of HD 139357 b relative to the habitable zone of HD 139357 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 139357 b — one full orbit around HD 139357 — lasts 1,124.8 Earth days, longer than an Earth year. It orbits at an average distance of 2.949 AU. Its orbit is mildly elliptical (eccentricity 0.10).
How Was HD 139357 b Discovered?
HD 139357 b was discovered in 2008 using the radial velocity method, with observations from Thueringer Landessternwarte Tautenburg.
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 139357 b?
HD 139357 b is 365.6 light-years (112.1 parsecs) from Earth. Light arriving here tonight left the planet around the year 1661. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 6,434,560 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 139357 b scores 0.19, ranking #3,972 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 139357
HD 139357
- Mass
- 2.69 M☉
Planetary System
HD 139357 b is the only planet known to orbit HD 139357 so far.
HD 139357 b — Complete Data
| Mass | 6,315.57 Earth masses (19.871 Jupiter masses) |
|---|---|
| Orbital period | 1,124.79 days |
| Orbital distance | 2.949 AU |
| Eccentricity | 0.099 |
| Earth Similarity Index | 0.19 |
| Distance from Earth | 365.6 light-years (112.1 parsecs) |
| Constellation | Draco |
| Discovery method | Radial Velocity |
| Discovery facility | Thueringer Landessternwarte Tautenburg |
| Discovery year | 2008 |
Data: NASA Exoplanet Archive, last updated 2023-06-12. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 139357 b
Is HD 139357 b habitable?
HD 139357 b is not known to orbit within the habitable zone of HD 139357.
How far away is HD 139357 b?
HD 139357 b is about 366 light-years from Earth in the constellation Draco. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 6,434,560 years to get there.
How long is a year on HD 139357 b?
One orbit around HD 139357 takes 1,124.8 Earth days.
Explore HD 139357 b in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
