HD 12648 b
HD 12648 b is a cold gas giant orbiting HD 12648 in the constellation Cepheus. It lies about 594 light-years from Earth and was discovered in 2015 using the radial velocity method.
Is HD 12648 b in the Habitable Zone?
HD 12648 b orbits inside the inner edge of the habitable zone of HD 12648. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of HD 12648: 6.090–14.824 AU (conservative: 7.714–14.054 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Orbit and Year Length
A year on HD 12648 b — one full orbit around HD 12648 — lasts 133.6 Earth days, between the years of Mercury (88 days) and Earth (365 days). It orbits at an average distance of 0.540 AU — comparable to the inner Solar System. Its orbit is nearly circular (eccentricity 0.040).
How Was HD 12648 b Discovered?
HD 12648 b was discovered in 2015 using the radial velocity method, with observations from Bohyunsan Optical Astronomical 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 12648 b?
HD 12648 b is 594.2 light-years (182.2 parsecs) from Earth. Light arriving here tonight left the planet around the year 1432. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 10,457,920 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 12648 b scores 0.07, ranking #4,878 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 12648
HD 12648
- Surface temperature
- 4,835 K (Sun: 5,772 K)
- Mass
- 0.67 M☉
- Radius
- 11.02 R☉
Planetary System
HD 12648 b is the only planet known to orbit HD 12648 so far.
HD 12648 b — Complete Data
| Mass (best estimate) | 622.95 Earth masses |
|---|---|
| Orbital period | 133.60 days |
| Orbital distance | 0.540 AU |
| Eccentricity | 0.040 |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 594.2 light-years (182.2 parsecs) |
| Constellation | Cepheus |
| Discovery method | Radial Velocity |
| Discovery facility | Bohyunsan Optical Astronomical Observatory |
| Discovery year | 2015 |
Data: NASA Exoplanet Archive, last updated 2018-09-04. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 12648 b
Is HD 12648 b habitable?
No — HD 12648 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is HD 12648 b?
HD 12648 b is about 594 light-years from Earth in the constellation Cepheus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 10,457,920 years to get there.
How long is a year on HD 12648 b?
One orbit around HD 12648 takes 133.6 Earth days.
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