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HD 153950 b

Cold Gas Giant Habitable Zone Scorpius

HD 153950 b is a cold gas giant orbiting HD 153950 in the constellation Scorpius. It lies about 158 light-years from Earth and was discovered in 2008 using the radial velocity method. It orbits within the habitable zone of its star — the region where liquid water could exist on a planet's surface.

938×Earth mass
499 dOrbital period
0.38Earth similarity
158 lyDistance
2008Discovered

Is HD 153950 b in the Habitable Zone?

HD 153950 b orbits within the optimistic habitable zone of HD 153950 — the broader region where liquid water might be possible under favorable atmospheric conditions.

HD 153950 b
Too hot Optimistic habitable zone Conservative habitable zone Too cold

Habitable zone of HD 153950: 1.057–2.469 AU (conservative: 1.338–2.341 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 153950 b — one full orbit around HD 153950 — lasts 499.4 Earth days, longer than an Earth year. It orbits at an average distance of 1.280 AU. Its orbit is highly elliptical (eccentricity 0.34), swinging dramatically closer to and farther from its star.

How Was HD 153950 b Discovered?

HD 153950 b was discovered in 2008 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 153950 b?

HD 153950 b is 158.0 light-years (48.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1868. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,780,800 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 153950 b scores 0.38, ranking #579 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.

The Host Star: HD 153950

HD 153950

Surface temperature
6,124 K (Sun: 5,772 K)
Mass
1.25 M☉
Radius
1.28 R☉

Planetary System

HD 153950 b is the only planet known to orbit HD 153950 so far.

HD 153950 b — Complete Data

Mass (best estimate)937.60 Earth masses
Orbital period499.40 days
Orbital distance1.280 AU
Eccentricity0.340
Earth Similarity Index0.38
Distance from Earth158.0 light-years (48.5 parsecs)
ConstellationScorpius
Discovery methodRadial Velocity
Discovery facilityLa Silla Observatory
Discovery year2008

Data: NASA Exoplanet Archive, last updated 2018-09-04. Earth Similarity Index: PHL @ UPR Arecibo.

Frequently Asked Questions About HD 153950 b

Is HD 153950 b habitable?

HD 153950 b orbits within the habitable zone of HD 153950, the region where liquid water could exist on a planet's surface. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.

How far away is HD 153950 b?

HD 153950 b is about 158 light-years from Earth in the constellation Scorpius. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,780,800 years to get there.

How long is a year on HD 153950 b?

One orbit around HD 153950 takes 499.4 Earth days.

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