Key parameters at a glance

A radius of 11.90 Earth radii
A mass of 8,646.20 Earth masses
Surface gravity around 61.06 g
An orbital period of 1,757.392 days
Semi-major axis 3.4960 AU
Distance from Earth 501.13 light-years
Earth Similarity Index 0.255
Travel time at Voyager 1 speed 8,837,408 years

HD 125390 b Planet Profile

Physical Specs

Radius

11.90 R⊕

Radius (Jupiter)

1.060 R♃

Mass

8,646.20 M⊕

Mass (Jupiter)

27.204 M♃

Density

28.20 g/cm³

Surface Gravity

61.06 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.255

HZ Position Unknown

Controversial No

Discovery

Year 2019

Method Radial Velocity

Facility W. M. Keck Observatory

Telescope 10 m Keck I Telescope

Size rank in cohort

Rank by radius

#1526of 1771

top 86.1%

This planet

11.90R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

2MASS J22501512+2325342 b 11.90 R⊕ KMT-2020-BLG-0414L c 11.90 R⊕ DENIS-P J082303.1-491201 b 11.90 R⊕

Metric	Earth	HD 125390 b	Jupiter
Radius (R⊕)	1.00	11.90	11.21
Mass (M⊕)	1.00	8,646.20	317.83
Density (g/cm³)	5.51	28.20	1.33
Surface Gravity (g)	1.00	61.06	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	8,646.204 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	7,043.113 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 125390

HIP

HIP 69888

TIC

TIC 27354139

Gaia DR2

Gaia DR2 1484890423248544256

Gaia DR3

Gaia DR3 1484890423248544256

System

HD 125390

Percentile among Gas Giant cohort

Radius 11.900 R⊕ · percentile 13 / cohort 1771

Mass 8,646.204 M⊕ · percentile 99 / cohort 1747

Orbital period 1,757.39 d · percentile 83 / cohort 1533

Distance 153.65 pc · percentile 45 / cohort 1759

ESI 0.255 · percentile 46 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

1,757.392 days

Semi-major axis

3.4960 AU

Eccentricity

0.597

Inclination

84.69 °

Year Length

A year here lasts about 4.81 Earth years on a highly eccentric trajectory at a mean orbital distance of 3.4960 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.255

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

Luhn et al. 2019

Instrument

HIRES Spectrometer

Publication

2019-04

Observation locale

Ground

Discovery cohort

Planets confirmed in 2019 at W. M. Keck Observatory (3 shown).

Kepler-65 e · Gas Giant HD 202696 b · Unclassified HD 202696 c · Unclassified

Host System: HD 125390

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

4,882 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

6.470 R☉

Stellar Mass

1.820 M☉

Metallicity [Fe/H]

-0.11

Extended Stellar Properties

Surface gravity (log g)

3.040 dex

Systemic radial velocity

-76.52 km/s

Metallicity ratio

[Fe/H]

Distance

153.65 parsec

Light-years 501.13 ly

V-band magnitude

8.21 mag

Voyager-speed travel 8,837,408 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

6.480 mas

Total Proper Motion

21.524 mas/yr

PM Right Ascension

-14.40 mas/yr

PM Declination

-16.00 mas/yr

Galactic Cartesian (pc)

x = -0.640 · y = -0.441 · z = 0.629

Equatorial (J2000)

RA 214.53875° · Dec 38.96691°

Galactic ℓ, b

71.647° · 68.401°

Ecliptic λ, β

193.541° · 48.792°

HTM-20 index

17719702