Confirmed Exoplanet Discovered 2008

HD 181433 d

A gas giant orbiting the k-type orange HD 181433, located approximately 87.7 light-years from Earth.

Key parameters at a glance

  • A radius of 13.20 Earth radii
  • A mass of 858.14 Earth masses
  • Surface gravity around 4.93 g
  • An orbital period of 6,896.100 days
  • Semi-major axis 6.7400 AU
  • Distance from Earth 87.66 light-years
  • Earth Similarity Index 0.389
  • Travel time at Voyager 1 speed 1,545,855 years

2 siblings around HD 181433

HD 181433 d shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet Type Radius (R⊕) Mass (M⊕) Period (d) Eq. T (K) Year
HD 181433 b Unclassified 1,708.65 9.375 2008
HD 181433 c Unclassified 2,207.00 1,018.500 2008
HD 181433 d this Gas Giant 13.20 858.14 6,896.100 2008

HD 181433 d Planet Profile

Physical Specs

Radius
13.20 R⊕
Radius (Jupiter)
1.180 R♃
Mass
858.14 M⊕
Mass (Jupiter)
2.700 M♃
Density
2.05 g/cm³
Surface Gravity
4.93 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.389
HZ Position Unknown
Controversial No

Discovery

Year 2008
Method Radial Velocity
Facility La Silla Observatory
Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#847of 1771

top 47.8%

This planet

13.20R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Metric Earth HD 181433 d Jupiter
Radius (R⊕)1.0013.2011.21
Mass (M⊕)1.00858.14317.83
Density (g/cm³)5.512.051.33
Surface Gravity (g)1.004.932.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 858.137 M⊕ Direct mass measurement (not derived).
Minimum mass (M sin i) 206.910 M⊕ Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD

HD 181433

HIP

HIP 95467

TIC

TIC 410399074

Gaia DR2

Gaia DR2 6434153380720177664

Gaia DR3

Gaia DR3 6434153380720177664

System

HD 181433

Percentile among Gas Giant cohort

Radius 13.200 R⊕ · percentile 49 / cohort 1771
Mass 858.137 M⊕ · percentile 63 / cohort 1747
Orbital period 6,896.10 d · percentile 94 / cohort 1533
Distance 26.88 pc · percentile 6 / cohort 1759
ESI 0.389 · percentile 82 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period
6,896.100 days
Semi-major axis
6.7400 AU
Eccentricity
0.444
Inclination
164.50 °

Year Length

A year here lasts about 18.88 Earth years on a highly eccentric trajectory at a mean orbital distance of 6.7400 AU.

Eq. Temperature

 

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.389

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

Bouchy et al. 2009

Instrument

HARPS Spectrograph

Publication

2009-03

Observation locale

Ground

Host System: HD 181433

Spectral Class

K-type orange

Effective Temperature

4,918 K — cooler than the Sun (5,778 K)

Estimated Age

6.70 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.790 R☉

Stellar Mass

0.860 M☉

Metallicity [Fe/H]

0.40

Extended Stellar Properties

Surface gravity (log g)

4.450 dex

Stellar density

2.142 g/cm³

Systemic radial velocity

39.78 km/s

Rotational v·sin i

1.50 km/s

Rotation period

54.00 days

Metallicity ratio

[M/H]

Distance
26.88 parsec
Light-years 87.66 ly
V-band magnitude
8.40 mag
Voyager-speed travel 1,545,855 yr

Multi-band Host Photometry — 12 bands

6.09.49.42B8.40V8.09Gaia7.49TESS7.38Ic6.66J6.24H6.09K6.09W16.06W26.09W36.00W4

Astrometric Data

Parallax

37.179 mas

Total Proper Motion

330.029 mas/yr

PM Right Ascension

-230.93 mas/yr

PM Declination

235.78 mas/yr

Galactic Cartesian (pc)

x = 0.145 · y = -0.372 · z = -0.917

Equatorial (J2000)

RA 291.28737° · Dec -66.46778°

Galactic ℓ, b

329.515° · -28.044°

Ecliptic λ, β

281.598° · -43.884°

HTM-20 index

1546352008

Observation Record

Photometric series

1

RV measurements

1

Archive notes

1

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