Key parameters at a glance

A radius of 3.33 Earth radii
A mass of 11.07 Earth masses
Surface gravity around 1.00 g
An orbital period of 20.129 days
Semi-major axis 0.1110 AU
Distance from Earth 41.30 light-years
Earth Similarity Index 0.604
Travel time at Voyager 1 speed 728,351 years
Almost certainly tidally locked to its host star given the close orbit

Context from the literature

Gliese 422 b is an exoplanet orbiting the red dwarf Gliese 422. Gliese 422 b was discovered in 2014, and the discovery was confirmed in 2020. It has a minimum mass of about ten times that of Earth.

Excerpted from Wikipedia · full article

GJ 422 b Planet Profile

Physical Specs

Radius

3.33 R⊕

Radius (Jupiter)

0.297 R♃

Mass

11.07 M⊕

Mass (Jupiter)

0.035 M♃

Density

1.65 g/cm³

Surface Gravity

1.00 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.604

HZ Position Unknown

Controversial No

Discovery

Year 2014

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#261of 1978

top 13.1%

This planet

3.33R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-264 b 3.33 R⊕ GJ 674 b 3.33 R⊕ Kepler-11 g 3.33 R⊕

Metric	Earth	GJ 422 b	Jupiter
Radius (R⊕)	1.00	3.33	11.21
Mass (M⊕)	1.00	11.07	317.83
Density (g/cm³)	5.51	1.65	1.33
Surface Gravity (g)	1.00	1.00	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	11.070 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HD 304043

HIP

HIP 55042

TIC

TIC 450545735

Gaia DR2

Gaia DR2 5339892367683264384

Gaia DR3

Gaia DR3 5339892367684811520

System

GJ 422

Percentile among Sub-Neptune cohort

Radius 3.330 R⊕ · percentile 87 / cohort 1978

Mass 11.070 M⊕ · percentile 80 / cohort 1978

Orbital period 20.13 d · percentile 62 / cohort 1946

Distance 12.66 pc · percentile 2 / cohort 1975

ESI 0.604 · percentile 83 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

20.129 days

Semi-major axis

0.1110 AU

Eccentricity

0.110

Inclination

— °

Year Length

A year here lasts approximately 20.13 Earth days (5.5% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1110 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.604

0 = alien, 1 = Earth-identical

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

Discovery Paper

Primary reference

Tuomi et al. 2014

Instrument

Multiple Instruments

Publication

2014-06

Observation locale

Ground

Discovery cohort

Planets confirmed in 2014 at Multiple Observatories (12 shown).

GJ 682 b · Super-Earth GJ 180 c · Sub-Neptune GJ 180 b · Sub-Neptune GJ 682 c · Sub-Neptune GJ 160.2 b · Sub-Neptune GJ 27.1 b · Sub-Neptune GJ 433 c · Neptune-like HIP 105854 b · Gas Giant TYC 1422-614-1 c · Gas Giant TYC 1422-614-1 b · Gas Giant HD 141399 c · Gas Giant HD 141399 d · Gas Giant

Host System: GJ 422

Spectral Class

M-type red dwarf

Effective Temperature

3,323 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.370 R☉

Stellar Mass

0.350 M☉

Metallicity [Fe/H]

—

Distance

12.66 parsec

Light-years 41.30 ly

V-band magnitude

11.66 mag

Voyager-speed travel 728,351 yr

Multi-band Host Photometry — 8 bands

Astrometric Data

Parallax

78.941 mas

Total Proper Motion

2,737.706 mas/yr

PM Right Ascension

-2,468.48 mas/yr

PM Declination

1,183.91 mas/yr

Galactic Cartesian (pc)

x = -0.527 · y = 0.103 · z = -0.844

Equatorial (J2000)

RA 168.98105° · Dec -57.54256°

Galactic ℓ, b

290.367° · 2.980°

Ecliptic λ, β

204.628° · -54.584°

HTM-20 index

-1601108511

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