Key parameters at a glance

A radius of 14.30 Earth radii
A mass of 146.20 Earth masses
Surface gravity around 0.71 g
An orbital period of 129.360 days
Semi-major axis 0.5300 AU
Distance from Earth 147.25 light-years
Earth Similarity Index 0.247
Travel time at Voyager 1 speed 2,596,747 years

HD 208487 b Planet Profile

Physical Specs

Radius

14.30 R⊕

Radius (Jupiter)

1.270 R♃

Mass

146.20 M⊕

Mass (Jupiter)

0.460 M♃

Density

0.28 g/cm³

Surface Gravity

0.71 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.247

HZ Position Unknown

Controversial No

Discovery

Year 2004

Method Radial Velocity

Facility Anglo-Australian Telescope

Telescope 3.9 m Anglo-Australian Telescope

Size rank in cohort

Rank by radius

#301of 1771

top 16.9%

This planet

14.30R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HIP 65407 b 14.30 R⊕ HD 30669 b 14.30 R⊕ HD 45652 b 14.30 R⊕

Metric	Earth	HD 208487 b	Jupiter
Radius (R⊕)	1.00	14.30	11.21
Mass (M⊕)	1.00	146.20	317.83
Density (g/cm³)	5.51	0.28	1.33
Surface Gravity (g)	1.00	0.71	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	146.201 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 208487

HIP

HIP 108375

TIC

TIC 197686484

Gaia DR2

Gaia DR2 6586580842340695040

Gaia DR3

Gaia DR3 6586580842340695040

System

HD 208487

Percentile among Gas Giant cohort

Radius 14.300 R⊕ · percentile 82 / cohort 1771

Mass 146.201 M⊕ · percentile 11 / cohort 1747

Orbital period 129.36 d · percentile 55 / cohort 1533

Distance 45.15 pc · percentile 16 / cohort 1759

ESI 0.247 · percentile 44 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

129.360 days

Semi-major axis

0.5300 AU

Eccentricity

0.370

Inclination

— °

Year Length

A year here lasts approximately 129.36 Earth days (35.4% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.5300 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.247

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Tinney et al. 2005

Instrument

UCLES Spectrograph

Publication

2005-04

Observation locale

Ground

Discovery cohort

Planets confirmed in 2004 at Anglo-Australian Telescope (3 shown).

HD 154857 b · Gas Giant HD 117618 b · Neptune-like HD 160691 c · Unclassified

Host System: HD 208487

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

6,134 K — hotter than the Sun (5,778 K)

Estimated Age

1.95 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.160 R☉

Stellar Mass

1.150 M☉

Metallicity [Fe/H]

0.09

Extended Stellar Properties

Surface gravity (log g)

4.340 dex

Stellar density

1.048 g/cm³

Systemic radial velocity

5.49 km/s

Rotational v·sin i

5.58 km/s

Activity index (log R'HK)

-4.900

Metallicity ratio

[Fe/H]

Distance

45.15 parsec

Light-years 147.25 ly

V-band magnitude

7.47 mag

Voyager-speed travel 2,596,747 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

22.121 mas

Total Proper Motion

155.918 mas/yr

PM Right Ascension

101.14 mas/yr

PM Declination

-118.67 mas/yr

Galactic Cartesian (pc)

x = 0.680 · y = -0.403 · z = -0.612

Equatorial (J2000)

RA 329.33325° · Dec -37.76414°

Galactic ℓ, b

5.410° · -52.128°

Ecliptic λ, β

317.936° · -23.671°

HTM-20 index

861045897

Observation Record

Photometric series

RV measurements

Archive notes