Finding Earth 2.0
GJ 3998 · M1

GJ 3998 d

Rank #124 of the ranked catalogue · Discovered by Radial Velocity in 2025

HZ 5%M sin i

0.129

Earth-2.0 index

0.758

Earth Similarity Index

5%

Habitable-zone probability

2.34 R⊕

Radius

Planet

Mass6.070 M⊕M sin i
Bulk density2.600 g/cm³
Orbital period41.7800 days
Semi-major axis0.18900 au
Eccentricity0.000
Incident flux1.200 S⊕
Equilibrium temperature266.0 K
Maximum angular separation10.42 masReflected-light contrast 2.66e-8 at Aᵍ = 0.30 and Lambertian quadrature.
Composite parameter sources3 · mixedThe archive may select different publications for different parameters; mixed-source is disclosed, not automatically penalised.
Default-solution coverage75%0% median composite-to-default difference over shared parameters.

Host star & system

HostGJ 3998
Spectral typeM1
Effective temperature3726 K
Radius0.500 R☉
Mass0.520 M☉
Distance18.1 pc / 59.2 ly
DiscoveryRadial Velocity, 2025