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CONFIRMED EXOPLANET · Super-Earth

GJ 3988 b

GJ 3988 b orbits the star GJ 3988, 32.3 light-years from Earth. It completes an orbit in 6.944 Earth days.

DISCOVERED 2023 · Radial Velocity

Get to know this world ↓
GJ 3988 b
ORBITAL VISUALISATION
Super-EarthPlanet type

Size-based classification; composition may be uncertain.

1.74 × Earth’s radiusSize

Around 74% wider than Earth.

6.944 daysYear length

Time to complete one orbit.

32.3 light-yearsDistance

Its light travels for roughly 32 years to reach us.

2023Discovered

Radial Velocity

Overview

GJ 3988 b is one of the confirmed worlds in the NASA Exoplanet Archive. Recorded as discovered in 2023. The credited discovery facility is Calar Alto 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 1.74 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 3.69 Earth masses (Msini). Radius: 1.74 Earth radii.

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

Orbit & year

A year here lasts 6.944 Earth days. Its recorded semi-major axis is 0.041 AU. One AU is roughly the Earth–Sun distance.

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

Host star

GJ 3988 · M4.5 V.

Effective temperature: 3,273 K.

Mass: 0.18 times the Sun’s mass.

Planetary system

1 confirmed planets are stored for this star.

GJ 3988 b · 6.944-day orbit

Discovery

Reported discovery year: 2023. Method: Radial Velocity. Facility: Calar Alto 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 348 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

Radius1.74 Earth radii
Mass / minimum mass3.69 Earth masses (Msini)
Orbital period6.9442 Earth days
Semi-major axis0.0405 AU
Eccentricity0
Equilibrium temperature348 K · estimated, not surface temperature
Host star temperature3,273 K
Host star mass0.1842 Solar masses
Host star radius0.19734 Solar radii
Distance9.9105 parsecs
Discovery year2,023
Discovery methodRadial Velocity
Discovery facilityCalar Alto Observatory
Discovery publication2023-12
Stellar spectral typeM4.5 V

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+0.42 / -0.41Gorrini et al. 2023
Orbital period+0.001 / -0.001Gorrini et al. 2023
Equilibrium temperature+17 / -16Gorrini et al. 2023

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.

Spotted something wrong? Report an error ↗

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