HN Peg b
HN Peg b is a cold gas giant orbiting the G0 V star HN Peg in the constellation Pegasus. It lies about 59 light-years from Earth and was discovered in 2006 using the imaging method.
How Big Is HN Peg b?
HN Peg b has a radius of 11.78 times that of Earth, or 1.05 times the radius of Jupiter. Its mass is 6,992 times that of Earth.
Is HN Peg b in the Habitable Zone?
The position of HN Peg b relative to the habitable zone of HN Peg cannot be precisely determined from the available orbital data.
Orbit and Year Length
HN Peg b orbits at an average distance of 773.000 AU.
How Was HN Peg b Discovered?
HN Peg b was discovered in 2006 using the imaging method, with observations from Spitzer Space Telescope.
Direct imaging captures actual pictures of a planet by blocking out the overwhelming glare of its host star. It works best for young, hot, massive planets on wide orbits.
How Far Away Is HN Peg b?
HN Peg b is 59.1 light-years (18.1 parsecs) from Earth. Light arriving here tonight left the planet around the year 1967. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,040,160 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. HN Peg b scores 0.07, ranking #4,790 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HN Peg
HN Peg
- Spectral type
- G0 V
- Age
- 0.3 billion years (Sun: 4.6)
Planetary System
HN Peg b is the only planet known to orbit HN Peg so far.
HN Peg b — Complete Data
| Radius | 11.777 Earth radii (1.051 Jupiter radii) |
|---|---|
| Mass | 6,991.57 Earth masses (21.999 Jupiter masses) |
| Orbital distance | 773.000 AU |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 59.1 light-years (18.1 parsecs) |
| Constellation | Pegasus |
| Discovery method | Imaging |
| Discovery facility | Spitzer Space Telescope |
| Discovery year | 2006 |
Data: NASA Exoplanet Archive, last updated 2014-05-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HN Peg b
Is HN Peg b habitable?
HN Peg b is not known to orbit within the habitable zone of HN Peg, and as a cold gas giant it is an unlikely candidate for life as we know it.
How far away is HN Peg b?
HN Peg b is about 59 light-years from Earth in the constellation Pegasus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,040,160 years to get there.
How big is HN Peg b compared to Earth?
HN Peg b has 11.78 times the radius of Earth and about 6,992 times its mass.
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