Key parameters at a glance

A radius of 12.40 Earth radii
A mass of 3,750.38 Earth masses
Surface gravity around 24.39 g
An orbital period of 571.300 days
Distance from Earth 239.67 light-years
Earth Similarity Index 0.361
Travel time at Voyager 1 speed 4,226,561 years

Gaia-4 b Planet Profile

Physical Specs

Radius

12.40 R⊕

Radius (Jupiter)

1.100 R♃

Mass

3,750.38 M⊕

Mass (Jupiter)

11.800 M♃

Density

10.80 g/cm³

Surface Gravity

24.39 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.361

HZ Position Unknown

Controversial No

Discovery

Year 2025

Method Astrometry

Facility European Space Agency (ESA) Gaia Satellite

Telescope 1.45 m x 0.5 m Telescope

Size rank in cohort

Rank by radius

#1298of 1771

top 73.2%

This planet

12.40R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 110014 b 12.40 R⊕ CFBDSIR J145829+101343 b 12.40 R⊕ MOA-2010-BLG-073L b 12.40 R⊕

Metric	Earth	Gaia-4 b	Jupiter
Radius (R⊕)	1.00	12.40	11.21
Mass (M⊕)	1.00	3,750.38	317.83
Density (g/cm³)	5.51	10.80	1.33
Surface Gravity (g)	1.00	24.39	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	3,750.375 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 166669918

Gaia DR2

Gaia DR2 1457486023639239296

Gaia DR3

Gaia DR3 1457486023639239296

System

Gaia-4

Percentile among Gas Giant cohort

Radius 12.400 R⊕ · percentile 25 / cohort 1771

Mass 3,750.375 M⊕ · percentile 90 / cohort 1747

Orbital period 571.30 d · percentile 70 / cohort 1533

Distance 73.48 pc · percentile 29 / cohort 1759

ESI 0.361 · percentile 74 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

571.300 days

Semi-major axis

— AU

Eccentricity

0.338

Inclination

116.90 °

Year Length

A year here lasts about 1.56 Earth years on a highly eccentric trajectory.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.361

0 = alien, 1 = Earth-identical

Detection Signatures

Radial velocity

Stellar wobble has been measured spectroscopically.

Astrometry

Positional wobble of the host star was measured.

Discovery Paper

Primary reference

Stef & Aacute Nsson et al. 2025

Instrument

Gaia CCD array

Publication

2025-02

Observation locale

Space

Discovery cohort

Planets confirmed in 2025 at European Space Agency (ESA) Gaia Satellite (2 shown).

HD 128717 b · Gas Giant Gaia-5 b · Gas Giant

Host System: Gaia-4

Spectral Class

K-type orange

Effective Temperature

4,034 K — cooler than the Sun (5,778 K)

Estimated Age

6.80 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.624 R☉

Stellar Mass

0.644 M☉

Metallicity [Fe/H]

0.05

Extended Stellar Properties

Surface gravity (log g)

4.680 dex

Stellar density

3.740 g/cm³

Systemic radial velocity

-17.53 km/s

Rotational v·sin i

2.00 km/s

Rotation period

13.30 days

Metallicity ratio

[Fe/H]

Distance

73.48 parsec

Light-years 239.67 ly

V-band magnitude

12.41 mag

Voyager-speed travel 4,226,561 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

13.580 mas

Total Proper Motion

77.671 mas/yr

PM Right Ascension

-75.54 mas/yr

PM Declination

18.07 mas/yr

Galactic Cartesian (pc)

x = -0.740 · y = -0.419 · z = 0.525

Equatorial (J2000)

RA 209.50638° · Dec 31.69549°

Galactic ℓ, b

54.407° · 74.815°

Ecliptic λ, β

193.329° · 40.447°

HTM-20 index

1087243510

Similar Worlds

HD 87816 c

Gas Giant · K-type orange

Radius 12.40 R⊕ · 434.5 ly

HD 95127 b

Gas Giant · K-type orange

Radius 12.40 R⊕ · 2,206.7 ly

HD 16905 b

Gas Giant · K-type orange

Radius 12.40 R⊕ · 129.6 ly

HD 110014 b

Gas Giant · K-type orange

Radius 12.40 R⊕ · 328.6 ly

TYC 4282-00605-1 b

Gas Giant · K-type orange

Radius 12.40 R⊕ · 1,513.8 ly

WISPIT 1 b

Gas Giant · K-type orange

Radius 12.40 R⊕ · 750.2 ly

Explore Related Categories

Gas Giant Planets Astrometry Discoveries European Space Agency (ESA) Gaia Satellite Mission K-type orange Hosts