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CONFIRMED EXOPLANET · Neptune-like

HD 103197 b

HD 103197 b orbits the star HD 103197, 186.4 light-years from Earth. It completes an orbit in 47.84 Earth days.

DISCOVERED 2011 · Radial Velocity

Get to know this world ↓
HD 103197 b
ORBITAL VISUALISATION
Neptune-likePlanet type

Size-based classification; composition may be uncertain.

5.83 × Earth’s radiusSize

Around 483% wider than Earth.

47.84 daysYear length

Time to complete one orbit.

186.4 light-yearsDistance

Its light travels for roughly 186 years to reach us.

2011Discovered

Radial Velocity

Overview

HD 103197 b is one of the confirmed worlds in the NASA Exoplanet Archive. Recorded as discovered in 2011. The credited discovery facility is La Silla Observatory. Its Radial Velocity evidence gives us a way to study a planet that is usually too faint to see directly.

Its recorded radius is 5.83 times Earth's radius. Size is useful for comparison, but it cannot establish surface conditions by itself.

The planet

The archive lists a mass or minimum-mass value of 28.6 Earth masses (Msini). Radius: 5.83 Earth radii.

Mass and radius constrain possible interiors; multiple compositions can fit a given set of measurements.

Orbit & year

A year here lasts 47.84 Earth days. Its recorded semi-major axis is 0.25 AU. One AU is roughly the Earth–Sun distance.

Eccentricity: 0. Zero describes a circular orbit; increasing values describe more elongated ellipses.

Host star

HD 103197 · K1 V(P).

Effective temperature: 5,250 K.

Mass: 0.8 times the Sun’s mass.

Planetary system

1 confirmed planets are stored for this star.

HD 103197 b · 47.84-day orbit

Discovery

Reported discovery year: 2011. Method: Radial Velocity. Facility: La Silla Observatory.

First stored in this atlas: 04/10/2026. This is an ingestion date, not a confirmation date.

How these methods work ↗

Potential habitability

The data here does not establish habitability, liquid water, or life. An appropriate atmosphere and many other conditions would be needed.

The listed equilibrium temperature is 475 K. This is an estimated energy-balance temperature, not a measured surface temperature.

Understand the habitable zone ↗

What do we actually know?

Observed

The underlying light, motion or timing signal. Usually not a photograph of the planet.

Measured

Parameters derived from observations, with instrument and model uncertainty.

Calculated

Our light-year conversion and browsing class are calculated from archive values.

Estimated

Equilibrium temperature is an energy-balance estimate, not surface weather.

Inferred

Possible composition depends on models and may not be unique.

Unknown

Surface conditions and the presence of life are not established here.

Measured signals are interpreted through models. The archive’s composite table combines published values and may include calculated estimates. Values do not necessarily form one self-consistent solution.

Radius and mass can be estimated or inferred, orbital period comes from recurring observations, and size classification is calculated by this site. Atmospheric and surface conditions remain unknown unless established by specific observations.

Consult the archive for individual parameter references and uncertainty intervals before scientific use.

Scientific data

Radius5.83 Earth radii
Mass / minimum mass28.6047 Earth masses (Msini)
Orbital period47.84 Earth days
Semi-major axis0.25 AU
Eccentricity0
Equilibrium temperature474.97 K · estimated, not surface temperature
Host star temperature5,250 K
Host star mass0.8 Solar masses
Host star radius0.88 Solar radii
Distance57.1463 parsecs
Discovery year2,011
Discovery methodRadial Velocity
Discovery facilityLa Silla Observatory
Discovery publication2011-02
Stellar spectral typeK1 V(P)

Uncertainties and parameter provenance

Archive uncertainty ranges and published references, where available. A missing uncertainty does not imply an exact value.

ParameterUncertainty / source
RadiusUpper uncertainty unavailable / Lower uncertainty unavailableCalculated Value
Mass / minimum mass+6.3566 / -6.3566Stassun et al. 2017
Orbital period+0.03 / -0.03Stassun et al. 2017
Equilibrium temperature+11.1 / -11.1Calculated Value

Sources

NASA Exoplanet Archive · Planetary Systems Composite Parameters (PSCompPars).

Open the scientific archive record ↗

Last changed in this atlas: 04/10/2026, 11:39:41. Read our methodology.

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