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HD 16175 b

Cold Gas Giant Habitable Zone Andromeda

HD 16175 b is a cold gas giant orbiting HD 16175 in the constellation Andromeda. It lies about 195 light-years from Earth and was discovered in 2009 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.

1,621×Earth mass
990 dOrbital period
0.39Earth similarity
195 lyDistance
2009Discovered

Is HD 16175 b in the Habitable Zone?

HD 16175 b orbits inside the conservative habitable zone of HD 16175 — the region where a rocky planet could sustain liquid water on its surface. This makes it one of the most interesting known exoplanets in the search for life.

HD 16175 b
Too hot Optimistic habitable zone Conservative habitable zone Too cold

Habitable zone of HD 16175: 1.366–3.202 AU (conservative: 1.730–3.036 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 16175 b — one full orbit around HD 16175 — lasts 990.0 Earth days, longer than an Earth year. It orbits at an average distance of 2.120 AU. Its orbit is highly elliptical (eccentricity 0.60), swinging dramatically closer to and farther from its star.

How Was HD 16175 b Discovered?

HD 16175 b was discovered in 2009 using the radial velocity method, with observations from Lick 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 16175 b?

HD 16175 b is 195.2 light-years (59.9 parsecs) from Earth. Light arriving here tonight left the planet around the year 1831. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 3,435,520 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 16175 b scores 0.39, ranking #499 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.

The Host Star: HD 16175

HD 16175

Surface temperature
5,981 K (Sun: 5,772 K)
Mass
1.63 M☉
Radius
1.72 R☉

Planetary System

HD 16175 b is the only planet known to orbit HD 16175 so far.

HD 16175 b — Complete Data

Mass (best estimate)1,620.93 Earth masses
Orbital period990.00 days
Orbital distance2.120 AU
Eccentricity0.600
Earth Similarity Index0.39
Distance from Earth195.2 light-years (59.9 parsecs)
ConstellationAndromeda
Discovery methodRadial Velocity
Discovery facilityLick Observatory
Discovery year2009

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

Frequently Asked Questions About HD 16175 b

Is HD 16175 b habitable?

HD 16175 b orbits within the habitable zone of HD 16175, the region where liquid water could exist on a planet's surface. It sits in the conservative habitable zone — the most promising region for habitability. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.

How far away is HD 16175 b?

HD 16175 b is about 195 light-years from Earth in the constellation Andromeda. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 3,435,520 years to get there.

How long is a year on HD 16175 b?

One orbit around HD 16175 takes 990.0 Earth days.

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