HD 12235 b
HD 12235 b is a Neptune-like planet orbiting HD 12235 in the constellation Pisces. It lies about 104 light-years from Earth and was discovered in 2022 using the radial velocity method.
Is HD 12235 b in the Habitable Zone?
The position of HD 12235 b relative to the habitable zone of HD 12235 cannot be precisely determined from the available orbital data.
Orbit and Year Length
A year on HD 12235 b — one full orbit around HD 12235 — lasts 4.36 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.054 AU — closer to its star than Mercury is to the Sun. Its orbit is highly elliptical (eccentricity 0.38), swinging dramatically closer to and farther from its star.
How Was HD 12235 b Discovered?
HD 12235 b was discovered in 2022 using the radial velocity method, with observations from Multiple Observatories.
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 12235 b?
HD 12235 b is 103.6 light-years (31.8 parsecs) from Earth. Light arriving here tonight left the planet around the year 1923. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 1,823,360 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 12235 b scores 0.20, ranking #3,864 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 12235
HD 12235
- Mass
- 1.10 M☉
The HD 12235 Planetary System
HD 12235 b is one of 2 known planets in the HD 12235 system. Its siblings:
- HD 12235 c (Cold Gas Giant)
HD 12235 b — Complete Data
| Mass (best estimate) | 10.49 Earth masses |
|---|---|
| Orbital period | 4.36 days |
| Orbital distance | 0.054 AU |
| Eccentricity | 0.376 |
| Earth Similarity Index | 0.20 |
| Distance from Earth | 103.6 light-years (31.8 parsecs) |
| Constellation | Pisces |
| Discovery method | Radial Velocity |
| Discovery facility | Multiple Observatories |
| Discovery year | 2022 |
Data: NASA Exoplanet Archive, last updated 2023-06-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 12235 b
Is HD 12235 b habitable?
HD 12235 b is not known to orbit within the habitable zone of HD 12235, and as a Neptune-like planet it is an unlikely candidate for life as we know it.
How far away is HD 12235 b?
HD 12235 b is about 104 light-years from Earth in the constellation Pisces. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 1,823,360 years to get there.
How long is a year on HD 12235 b?
One orbit around HD 12235 takes 4.4 Earth days — short enough that 84 of its years would fit into one Earth year.
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