HD 85390 b
HD 85390 b is a Neptune-like planet orbiting HD 85390 in the constellation Vela. It lies about 109 light-years from Earth and was discovered in 2009 using the radial velocity method.
Is HD 85390 b in the Habitable Zone?
The position of HD 85390 b relative to the habitable zone of HD 85390 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 85390 b — one full orbit around HD 85390 — lasts 799.5 Earth days, longer than an Earth year. It orbits at an average distance of 1.373 AU. Its orbit is highly elliptical (eccentricity 0.50), swinging dramatically closer to and farther from its star.
How Was HD 85390 b Discovered?
HD 85390 b was discovered in 2009 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 85390 b?
HD 85390 b is 109.3 light-years (33.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1917. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,923,680 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 85390 b scores 0.34, ranking #811 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 85390
HD 85390
- Surface temperature
- 5,186 K (Sun: 5,772 K)
- Mass
- 0.76 M☉
Planetary System
HD 85390 b is the only planet known to orbit HD 85390 so far.
HD 85390 b — Complete Data
| Mass (best estimate) | 31.47 Earth masses |
|---|---|
| Orbital period | 799.52 days |
| Orbital distance | 1.373 AU |
| Eccentricity | 0.500 |
| Earth Similarity Index | 0.34 |
| Distance from Earth | 109.3 light-years (33.5 parsecs) |
| Constellation | Vela |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2009 |
Data: NASA Exoplanet Archive, last updated 2019-03-11. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 85390 b
Is HD 85390 b habitable?
HD 85390 b is not known to orbit within the habitable zone of HD 85390, and as a Neptune-like planet it is an unlikely candidate for life as we know it.
How far away is HD 85390 b?
HD 85390 b is about 109 light-years from Earth in the constellation Vela. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,923,680 years to get there.
How long is a year on HD 85390 b?
One orbit around HD 85390 takes 799.5 Earth days.
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