HD 100777 b
HD 100777 b is a cold gas giant orbiting the G8 V star HD 100777 in the constellation Leo. It lies about 162 light-years from Earth and was discovered in 2007 using the radial velocity method.
Is HD 100777 b in the Habitable Zone?
The position of HD 100777 b relative to the habitable zone of HD 100777 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 100777 b — one full orbit around HD 100777 — lasts 383.0 Earth days, longer than an Earth year. It orbits at an average distance of 1.060 AU — comparable to the inner Solar System. Its orbit is highly elliptical (eccentricity 0.38), swinging dramatically closer to and farther from its star.
How Was HD 100777 b Discovered?
HD 100777 b was discovered in 2007 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 100777 b?
HD 100777 b is 161.6 light-years (49.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1865. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,844,160 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 100777 b scores 0.39, ranking #529 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 100777
HD 100777
- Spectral type
- G8 V
- Mass
- 1.08 M☉
- Age
- 5.7 billion years (Sun: 4.6)
Planetary System
HD 100777 b is the only planet known to orbit HD 100777 so far.
HD 100777 b — Complete Data
| Mass | 390.93 Earth masses (1.230 Jupiter masses) |
|---|---|
| Orbital period | 383.00 days |
| Orbital distance | 1.060 AU |
| Eccentricity | 0.380 |
| Earth Similarity Index | 0.39 |
| Distance from Earth | 161.6 light-years (49.5 parsecs) |
| Constellation | Leo |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2007 |
Data: NASA Exoplanet Archive, last updated 2023-09-05. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 100777 b
Is HD 100777 b habitable?
HD 100777 b is not known to orbit within the habitable zone of HD 100777, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is HD 100777 b?
HD 100777 b is about 162 light-years from Earth in the constellation Leo. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,844,160 years to get there.
How long is a year on HD 100777 b?
One orbit around HD 100777 takes 383.0 Earth days.
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