HD 113538 b
HD 113538 b is a cold gas giant orbiting the K9 V star HD 113538 in the constellation Centaurus. It lies about 53 light-years from Earth and was discovered in 2010 using the radial velocity method.
Is HD 113538 b in the Habitable Zone?
HD 113538 b orbits beyond the outer edge of the habitable zone of HD 113538. At that distance, any surface water would almost certainly be frozen.
Habitable zone of HD 113538: 0.253–0.626 AU (conservative: 0.321–0.594 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Orbit and Year Length
A year on HD 113538 b — one full orbit around HD 113538 — lasts 663.2 Earth days, longer than an Earth year. It orbits at an average distance of 1.240 AU. Its orbit is mildly elliptical (eccentricity 0.14).
How Was HD 113538 b Discovered?
HD 113538 b was discovered in 2010 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 113538 b?
HD 113538 b is 53.1 light-years (16.3 parsecs) from Earth. Light arriving here tonight left the planet around the year 1973. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 934,560 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 113538 b scores 0.13, ranking #4,306 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: HD 113538
HD 113538
- Spectral type
- K9 V
- Surface temperature
- 4,462 K (Sun: 5,772 K)
- Mass
- 0.59 M☉
- Radius
- 0.53 R☉
- Age
- 4.3 billion years (Sun: 4.6)
The HD 113538 Planetary System
HD 113538 b is one of 2 known planets in the HD 113538 system. Its siblings:
- HD 113538 c (Cold Gas Giant)
HD 113538 b — Complete Data
| Mass (best estimate) | 114.41 Earth masses |
|---|---|
| Orbital period | 663.20 days |
| Orbital distance | 1.240 AU |
| Eccentricity | 0.140 |
| Earth Similarity Index | 0.13 |
| Distance from Earth | 53.1 light-years (16.3 parsecs) |
| Constellation | Centaurus |
| Discovery method | Radial Velocity |
| Discovery facility | La Silla Observatory |
| Discovery year | 2010 |
Data: NASA Exoplanet Archive, last updated 2015-01-08. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About HD 113538 b
Is HD 113538 b habitable?
No — HD 113538 b orbits outside the habitable zone of HD 113538 and is likely too cold for liquid water on its surface.
How far away is HD 113538 b?
HD 113538 b is about 53 light-years from Earth in the constellation Centaurus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 934,560 years to get there.
How long is a year on HD 113538 b?
One orbit around HD 113538 takes 663.2 Earth days.
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