Key parameters at a glance

A radius of 13.40 Earth radii
A mass of 572.07 Earth masses
Surface gravity around 3.19 g
An orbital period of 380.800 days
Semi-major axis 1.2000 AU
Distance from Earth 65.92 light-years
Earth Similarity Index 0.359
Travel time at Voyager 1 speed 1,162,442 years

alf Ari b Planet Profile

Physical Specs

Radius

13.40 R⊕

Radius (Jupiter)

1.200 R♃

Mass

572.07 M⊕

Mass (Jupiter)

1.800 M♃

Density

1.31 g/cm³

Surface Gravity

3.19 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.359

HZ Position Unknown

Controversial No

Discovery

Year 2010

Method Radial Velocity

Facility Bohyunsan Optical Astronomical Observatory

Telescope 1.8 m Telescope

Size rank in cohort

Rank by radius

#730of 1771

top 41.2%

This planet

13.40R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

HD 114783 c 13.40 R⊕ HIP 79431 b 13.40 R⊕ HD 68988 b 13.40 R⊕

Metric	Earth	alf Ari b	Jupiter
Radius (R⊕)	1.00	13.40	11.21
Mass (M⊕)	1.00	572.07	317.83
Density (g/cm³)	5.51	1.31	1.33
Surface Gravity (g)	1.00	3.19	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	572.070 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 12929

HIP

HIP 9884

TIC

TIC 306349516

System

alf Ari

Percentile among Gas Giant cohort

Radius 13.400 R⊕ · percentile 56 / cohort 1771

Mass 572.070 M⊕ · percentile 52 / cohort 1747

Orbital period 380.80 d · percentile 63 / cohort 1533

Distance 20.21 pc · percentile 4 / cohort 1759

ESI 0.359 · percentile 73 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

380.800 days

Semi-major axis

1.2000 AU

Eccentricity

0.250

Inclination

— °

Year Length

A year here lasts about 1.04 Earth years on a mildly elliptical path at a mean orbital distance of 1.2000 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.359

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Lee et al. 2011

Instrument

BOES Echelle Spectrograph

Publication

2011-05

Observation locale

Ground

Host System: alf Ari

Spectral Class

K-type orange

Effective Temperature

4,553 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

13.900 R☉

Stellar Mass

1.500 M☉

Metallicity [Fe/H]

-0.09

Extended Stellar Properties

Surface gravity (log g)

2.330 dex

Systemic radial velocity

-14.60 km/s

Rotational v·sin i

3.10 km/s

Metallicity ratio

[Fe/H]

Distance

20.21 parsec

Light-years 65.92 ly

V-band magnitude

2.01 mag

Voyager-speed travel 1,162,442 yr

Multi-band Host Photometry — 10 bands

Astrometric Data

Parallax

49.480 mas

Total Proper Motion

240.410 mas/yr

PM Right Ascension

191.00 mas/yr

PM Declination

-146.00 mas/yr

Galactic Cartesian (pc)

x = 0.780 · y = 0.483 · z = 0.398

Equatorial (J2000)

RA 31.79329° · Dec 23.46242°

Galactic ℓ, b

144.578° · -36.206°

Ecliptic λ, β

37.659° · 9.965°

HTM-20 index

-641703371

Similar Worlds

HD 93083 b

Gas Giant · K-type orange

Radius 13.40 R⊕ · 93.0 ly

Kepler-48 e

Gas Giant · K-type orange

Radius 13.40 R⊕ · 1,000.4 ly

HD 47366 b

Gas Giant · K-type orange

Radius 13.40 R⊕ · 275.1 ly

HIP 114933 b

Gas Giant · K-type orange

Radius 13.40 R⊕ · 331.9 ly

HD 114783 c

Gas Giant · K-type orange

Radius 13.40 R⊕ · 68.7 ly

HD 4732 b

Gas Giant · K-type orange

Radius 13.40 R⊕ · 178.7 ly

Explore Related Categories

Gas Giant Planets Radial Velocity Discoveries Bohyunsan Optical Astronomical Observatory Mission K-type orange Hosts