Key parameters at a glance

A radius of 12.70 Earth radii
A mass of 2,034.10 Earth masses
Surface gravity around 12.61 g
An orbital period of 2,142.000 days
Semi-major axis 4.2100 AU
Distance from Earth 336.08 light-years
Earth Similarity Index 0.442
Travel time at Voyager 1 speed 5,926,844 years

Context from the literature

HD 120084 is a star with an orbiting exoplanet in the northern constellation of Ursa Minor. With an apparent magnitude of 5.91, it is just visible to the naked eye in suburban skies. The distance to this system is 339 light-years based on parallax measurements, but it is drifting closer to the Sun with a radial velocity of −9 km/s.

Excerpted from Wikipedia · full article

HD 120084 b Planet Profile

Physical Specs

Radius

12.70 R⊕

Radius (Jupiter)

1.130 R♃

Mass

2,034.10 M⊕

Mass (Jupiter)

6.400 M♃

Density

5.46 g/cm³

Surface Gravity

12.61 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.442

HZ Position Unknown

Controversial No

Discovery

Year 2013

Method Radial Velocity

Facility Okayama Astrophysical Observatory

Telescope 1.88 m Telescope

Size rank in cohort

Rank by radius

#1130of 1771

top 63.7%

This planet

12.70R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 168863 b 12.70 R⊕ HD 233604 b 12.70 R⊕ Kepler-424 c 12.70 R⊕

Metric	Earth	HD 120084 b	Jupiter
Radius (R⊕)	1.00	12.70	11.21
Mass (M⊕)	1.00	2,034.10	317.83
Density (g/cm³)	5.51	5.46	1.33
Surface Gravity (g)	1.00	12.61	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	2,034.102 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	1,195.670 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 120084

HIP

HIP 66903

TIC

TIC 284181945

Gaia DR2

Gaia DR2 1715055487257379968

Gaia DR3

Gaia DR3 1715055487257379968

System

HD 120084

Percentile among Gas Giant cohort

Radius 12.700 R⊕ · percentile 34 / cohort 1771

Mass 2,034.102 M⊕ · percentile 80 / cohort 1747

Orbital period 2,142.00 d · percentile 85 / cohort 1533

Distance 103.04 pc · percentile 35 / cohort 1759

ESI 0.442 · percentile 98 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

2,142.000 days

Semi-major axis

4.2100 AU

Eccentricity

0.483

Inclination

38.00 °

Year Length

A year here lasts about 5.86 Earth years on a highly eccentric trajectory at a mean orbital distance of 4.2100 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.442

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

Sato et al. 2013

Instrument

HIDES Echelle Spectrograph

Publication

2013-08

Observation locale

Ground

Discovery cohort

Planets confirmed in 2013 at Okayama Astrophysical Observatory (2 shown).

HD 2952 b · Gas Giant ome Ser b · Gas Giant

Host System: HD 120084

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

4,879 K — cooler than the Sun (5,778 K)

Estimated Age

1.02 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

10.370 R☉

Stellar Mass

2.160 M☉

Metallicity [Fe/H]

0.10

Extended Stellar Properties

Surface gravity (log g)

2.740 dex

Systemic radial velocity

-8.80 km/s

Rotational v·sin i

2.44 km/s

Metallicity ratio

[Fe/H]

Distance

103.04 parsec

Light-years 336.08 ly

V-band magnitude

5.91 mag

Voyager-speed travel 5,926,844 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

9.676 mas

Total Proper Motion

79.817 mas/yr

PM Right Ascension

-65.09 mas/yr

PM Declination

46.20 mas/yr

Galactic Cartesian (pc)

x = -0.186 · y = -0.090 · z = 0.978

Equatorial (J2000)

RA 205.66199° · Dec 78.06464°

Galactic ℓ, b

119.564° · 38.727°

Ecliptic λ, β

121.262° · 68.951°

HTM-20 index

1289149261

Observation Record

Photometric series

RV measurements

Archive notes

Wikipedia → Image: Wikimedia Commons · Ursa Minor constellation map.png: Torsten Bronger / derivative work: Kxx · CC BY-SA 3.0