Key parameters at a glance

A radius of 12.50 Earth radii
A mass of 2,980.91 Earth masses
Surface gravity around 19.08 g
An orbital period of 7,593.405 days
Semi-major axis 7.4270 AU
Distance from Earth 155.73 light-years
Earth Similarity Index 0.392
Travel time at Voyager 1 speed 2,746,224 years

HD 181234 b Planet Profile

Physical Specs

Radius

12.50 R⊕

Radius (Jupiter)

1.120 R♃

Mass

2,980.91 M⊕

Mass (Jupiter)

9.379 M♃

Density

8.39 g/cm³

Surface Gravity

19.08 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.392

HZ Position Unknown

Controversial No

Discovery

Year 2019

Method Radial Velocity

Facility La Silla Observatory

Telescope 1.2 m Leonhard Euler Telescope

Size rank in cohort

Rank by radius

#1235of 1771

top 69.7%

This planet

12.50R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 156279 c 12.50 R⊕ HD 33283 b 12.50 R⊕ HD 156279 b 12.50 R⊕

Metric	Earth	HD 181234 b	Jupiter
Radius (R⊕)	1.00	12.50	11.21
Mass (M⊕)	1.00	2,980.91	317.83
Density (g/cm³)	5.51	8.39	1.33
Surface Gravity (g)	1.00	19.08	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	2,980.913 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	2,660.237 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 181234

HIP

HIP 95015

TIC

TIC 3409107

Gaia DR2

Gaia DR2 4201307051566729984

Gaia DR3

Gaia DR3 4201307051566729984

System

HD 181234

Percentile among Gas Giant cohort

Radius 12.500 R⊕ · percentile 28 / cohort 1771

Mass 2,980.913 M⊕ · percentile 86 / cohort 1747

Orbital period 7,593.41 d · percentile 94 / cohort 1533

Distance 47.75 pc · percentile 18 / cohort 1759

ESI 0.392 · percentile 84 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

7,593.405 days

Semi-major axis

7.4270 AU

Eccentricity

0.726

Inclination

98.73 °

Year Length

A year here lasts about 20.79 Earth years on a highly eccentric trajectory at a mean orbital distance of 7.4270 AU.

Extended Orbital Architecture

RV semi-amplitude (K)

126.925 m/s

Transit mid-time (BJD)

2,457,580.0000

Long. of periastron (ω)

95.37°

Angular separation (arcsec)

156.00000

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.392

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

Rickman et al. 2019

Instrument

CORALIE Spectrograph

Publication

2019-05

Observation locale

Ground

Discovery cohort

Planets confirmed in 2019 at La Silla Observatory (12 shown).

HD 20781 b · Rocky Terrestrial HD 20781 c · Sub-Neptune HD 21693 b · Sub-Neptune HD 45184 c · Sub-Neptune HD 134060 b · Sub-Neptune HD 31527 b · Sub-Neptune HD 20781 d · Sub-Neptune HD 20003 b · Sub-Neptune HD 31527 d · Sub-Neptune HD 45184 b · Sub-Neptune HD 51608 b · Sub-Neptune HD 136352 d · Sub-Neptune

Host System: HD 181234

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,386 K — cooler than the Sun (5,778 K)

Estimated Age

6.32 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.059 R☉

Stellar Mass

0.940 M☉

Metallicity [Fe/H]

0.32

Extended Stellar Properties

Surface gravity (log g)

4.375 dex

Stellar density

1.268 g/cm³

Systemic radial velocity

-46.42 km/s

Rotational v·sin i

2.11 km/s

Rotation period

50.80 days

Activity index (log R'HK)

-5.080

Metallicity ratio

[Fe/H]

Distance

47.75 parsec

Light-years 155.73 ly

V-band magnitude

8.59 mag

Voyager-speed travel 2,746,224 yr

Multi-band Host Photometry — 7 bands

Astrometric Data

Parallax

20.916 mas

Total Proper Motion

341.128 mas/yr

PM Right Ascension

-122.75 mas/yr

PM Declination

-318.28 mas/yr

Galactic Cartesian (pc)

x = 0.337 · y = -0.927 · z = -0.162

Equatorial (J2000)

RA 289.99987° · Dec -9.32497°

Galactic ℓ, b

27.780° · -10.547°

Ecliptic λ, β

290.238° · 12.720°

HTM-20 index

520958740