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HD 51608 b

Neptune-like Carina

HD 51608 b is a Neptune-like planet orbiting the G7 V star HD 51608 in the constellation Carina. It lies about 114 light-years from Earth and was discovered in 2019 using the radial velocity method.

12.8×Earth mass
14 dOrbital period
0.21Earth similarity
114 lyDistance
2019Discovered

Is HD 51608 b in the Habitable Zone?

HD 51608 b orbits inside the inner edge of the habitable zone of HD 51608. So close to its star, surface conditions are far too hot for liquid water.

HD 51608 b
Too hot Optimistic habitable zone Conservative habitable zone Too cold

Habitable zone of HD 51608: 0.581–1.385 AU (conservative: 0.735–1.313 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 51608 b — one full orbit around HD 51608 — lasts 14.1 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.106 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.09).

How Was HD 51608 b Discovered?

HD 51608 b was discovered in 2019 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 51608 b?

HD 51608 b is 114.3 light-years (35.1 parsecs) from Earth. Light arriving here tonight left the planet around the year 1912. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,011,680 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 51608 b scores 0.21, ranking #3,762 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.

The Host Star: HD 51608

HD 51608

Spectral type
G7 V
Surface temperature
5,358 K (Sun: 5,772 K)
Mass
0.80 M☉
Luminosity
0.5700 L☉

The HD 51608 Planetary System

HD 51608 b is one of 2 known planets in the HD 51608 system. Its siblings:

HD 51608 b — Complete Data

Mass (best estimate)12.77 Earth masses
Orbital period14.07 days
Orbital distance0.106 AU
Eccentricity0.090
Earth Similarity Index0.21
Distance from Earth114.3 light-years (35.1 parsecs)
ConstellationCarina
Discovery methodRadial Velocity
Discovery facilityLa Silla Observatory
Discovery year2019

Data: NASA Exoplanet Archive, last updated 2019-02-05. Earth Similarity Index: PHL @ UPR Arecibo.

Frequently Asked Questions About HD 51608 b

Is HD 51608 b habitable?

No — HD 51608 b orbits too close to its star and is too hot for liquid water to exist on its surface.

How far away is HD 51608 b?

HD 51608 b is about 114 light-years from Earth in the constellation Carina. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,011,680 years to get there.

How long is a year on HD 51608 b?

One orbit around HD 51608 takes 14.1 Earth days — short enough that 26 of its years would fit into one Earth year.

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