Confirmed Exoplanet Discovered 2008

HD 181433 b

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

Key parameters at a glance

  • A mass of 1,708.65 Earth masses
  • An orbital period of 9.375 days
  • Semi-major axis 0.0828 AU
  • Distance from Earth 87.66 light-years
  • Travel time at Voyager 1 speed 1,545,855 years
  • Almost certainly tidally locked to its host star given the close orbit

2 siblings around HD 181433

HD 181433 b 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 this Unclassified 1,708.65 9.375 2008
HD 181433 c Unclassified 2,207.00 1,018.500 2008
HD 181433 d Gas Giant 13.20 858.14 6,896.100 2008

HD 181433 b Planet Profile

Physical Specs

Radius
R⊕
Radius (Jupiter)
R♃
Mass
1,708.65 M⊕
Mass (Jupiter)
5.376 M♃
Density
g/cm³
Surface Gravity
g (Earth)

Classification

Planet Type

Unclassified

ESI Score
HZ Position Unknown
Controversial No

Discovery

Year 2008
Method Radial Velocity
Facility La Silla Observatory
Telescope 3.6 m ESO Telescope
Metric Earth HD 181433 b Jupiter
Radius (R⊕)1.0011.21
Mass (M⊕)1.001,708.65317.83
Density (g/cm³)5.511.33
Surface Gravity (g)1.002.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 1,708.646 M⊕ Direct mass measurement (not derived).
Minimum mass (M sin i) 7.220 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 Unclassified cohort

Mass 1,708.646 M⊕ · percentile 48 / cohort 42
Orbital period 9.37 d · percentile 28 / cohort 43
Distance 26.88 pc · percentile 35 / cohort 43

Orbit & Habitability

Orbital Dynamics

Period
9.375 days
Semi-major axis
0.0828 AU
Eccentricity
0.396
Inclination
0.25 °

Year Length

A year here lasts approximately 9.37 Earth days (2.6% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.0828 AU.

Eq. Temperature

 

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0 = alien, 1 = Earth-identical

Insufficient insolation data. Close-orbiting tidally-locked around a cool host.

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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