Key parameters at a glance

A mass of 587.98 Earth masses
An orbital period of 5,300.000 days
Semi-major axis 4.8500 AU
Distance from Earth 54.26 light-years
Travel time at Voyager 1 speed 956,943 years

GJ 508.2 b Planet Profile

Physical Specs

Radius

— R⊕

Radius (Jupiter)

— R♃

Mass

587.98 M⊕

Mass (Jupiter)

1.850 M♃

Density

— g/cm³

Surface Gravity

— g (Earth)

Classification

Planet Type

Unclassified

ESI Score —

HZ Position Unknown

Controversial No

Discovery

Year 2025

Method Radial Velocity

Facility Calar Alto Observatory

Telescope 3.5 m telescope

Metric	Earth	GJ 508.2 b	Jupiter
Radius (R⊕)	1.00	—	11.21
Mass (M⊕)	1.00	587.98	317.83
Density (g/cm³)	5.51	—	1.33
Surface Gravity (g)	1.00	—	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	587.983 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HIP

HIP 65143

TIC

TIC 43133318

Gaia DR2

Gaia DR2 1472903753640492160

Gaia DR3

Gaia DR3 1472903753640492160

System

GJ 508.2

Percentile among Unclassified cohort

Mass 587.983 M⊕ · percentile 17 / cohort 42

Orbital period 5,300.00 d · percentile 93 / cohort 43

Distance 16.64 pc · percentile 14 / cohort 43

Orbit & Habitability

Orbital Dynamics

Period

5,300.000 days

Semi-major axis

4.8500 AU

Eccentricity

0.270

Inclination

— °

Year Length

A year here lasts about 14.51 Earth years on a mildly elliptical path at a mean orbital distance of 4.8500 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

—

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Morales et al. 2025

Instrument

CARMENES

Publication

2025-07

Observation locale

Ground

Discovery cohort

Planets confirmed in 2025 at Calar Alto Observatory (8 shown).

G 261-6 b · Rocky Terrestrial G 192-15 b · Rocky Terrestrial G 268-110 b · Rocky Terrestrial KOBE-1 c · Sub-Neptune TOI-2093 b · Sub-Neptune KOBE-1 b · Sub-Neptune GJ 9773 b · Gas Giant G 192-15 c · Sub-Neptune

Host System: GJ 508.2

Spectral Class

M-type red dwarf

Effective Temperature

3,720 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.530 R☉

Stellar Mass

0.540 M☉

Metallicity [Fe/H]

-0.15

Extended Stellar Properties

Surface gravity (log g)

4.712 dex

Stellar density

5.010 g/cm³

Rotational v·sin i

2.00 km/s

Rotation period

36.00 days

Metallicity ratio

[Fe/H]

Distance

16.64 parsec

Light-years 54.26 ly

V-band magnitude

10.61 mag

Voyager-speed travel 956,943 yr

Multi-band Host Photometry — 13 bands

Astrometric Data

Parallax

60.077 mas

Total Proper Motion

567.730 mas/yr

PM Right Ascension

483.71 mas/yr

PM Declination

-297.23 mas/yr

Galactic Cartesian (pc)

x = -0.775 · y = -0.286 · z = 0.563

Equatorial (J2000)

RA 200.24439° · Dec 34.27766°

Galactic ℓ, b

83.155° · 80.444°

Ecliptic λ, β

182.825° · 39.084°

HTM-20 index

-55980382

Similar Worlds

TOI-1634 c

Unclassified · M-type red dwarf

Radius — R⊕ · 115.0 ly

Explore Related Categories

Unclassified Planets Radial Velocity Discoveries Calar Alto Observatory Mission M-type red dwarf Hosts