Key parameters at a glance

A radius of 13.90 Earth radii
A mass of 265.71 Earth masses
Surface gravity around 1.38 g
An orbital period of 1,019.740 days
Semi-major axis 2.1000 AU
Distance from Earth 149.70 light-years
Earth Similarity Index 0.294
Travel time at Voyager 1 speed 2,640,018 years

HD 187085 b Planet Profile

Physical Specs

Radius

13.90 R⊕

Radius (Jupiter)

1.240 R♃

Mass

265.71 M⊕

Mass (Jupiter)

0.836 M♃

Density

0.54 g/cm³

Surface Gravity

1.38 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.294

HZ Position Unknown

Controversial No

Discovery

Year 2006

Method Radial Velocity

Facility Anglo-Australian Telescope

Telescope 3.9 m Anglo-Australian Telescope

Size rank in cohort

Rank by radius

#456of 1771

top 25.7%

This planet

13.90R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

24 Sex c 13.90 R⊕ HD 148156 b 13.90 R⊕ HD 134987 c 13.90 R⊕

Metric	Earth	HD 187085 b	Jupiter
Radius (R⊕)	1.00	13.90	11.21
Mass (M⊕)	1.00	265.71	317.83
Density (g/cm³)	5.51	0.54	1.33
Surface Gravity (g)	1.00	1.38	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	265.706 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 187085

HIP

HIP 97546

TIC

TIC 300081980

Gaia DR2

Gaia DR2 6692069568458919040

Gaia DR3

Gaia DR3 6692069568458919040

System

HD 187085

Percentile among Gas Giant cohort

Radius 13.900 R⊕ · percentile 72 / cohort 1771

Mass 265.706 M⊕ · percentile 29 / cohort 1747

Orbital period 1,019.74 d · percentile 77 / cohort 1533

Distance 45.90 pc · percentile 17 / cohort 1759

ESI 0.294 · percentile 56 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

1,019.740 days

Semi-major axis

2.1000 AU

Eccentricity

0.251

Inclination

— °

Year Length

A year here lasts about 2.79 Earth years on a mildly elliptical path at a mean orbital distance of 2.1000 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.294

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Jones et al. 2006

Instrument

UCLES Spectrograph

Publication

2006-06

Observation locale

Ground

Discovery cohort

Planets confirmed in 2006 at Anglo-Australian Telescope (3 shown).

HD 159868 b · Gas Giant HD 23127 b · Gas Giant HD 20782 b · Gas Giant

Host System: HD 187085

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

6,117 K — hotter than the Sun (5,778 K)

Estimated Age

2.75 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.270 R☉

Stellar Mass

1.189 M☉

Metallicity [Fe/H]

0.12

Extended Stellar Properties

Surface gravity (log g)

4.279 dex

Stellar density

0.654 g/cm³

Systemic radial velocity

15.38 km/s

Rotational v·sin i

5.10 km/s

Rotation period

21.00 days

Activity index (log R'HK)

-4.930

Metallicity ratio

[Fe/H]

Distance

45.90 parsec

Light-years 149.70 ly

V-band magnitude

7.22 mag

Voyager-speed travel 2,640,018 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

21.758 mas

Total Proper Motion

103.595 mas/yr

PM Right Ascension

8.46 mas/yr

PM Declination

-103.25 mas/yr

Galactic Cartesian (pc)

x = 0.364 · y = -0.702 · z = -0.613

Equatorial (J2000)

RA 297.39157° · Dec -37.78099°

Galactic ℓ, b

2.201° · -27.120°

Ecliptic λ, β

292.275° · -16.437°

HTM-20 index

-1674731019

Observation Record

Photometric series

RV measurements

Archive notes