Key parameters at a glance

A radius of 2.41 Earth radii
A mass of 6.40 Earth masses
Surface gravity around 1.10 g
An orbital period of 24.329 days
Semi-major axis 0.1290 AU
Distance from Earth 38.95 light-years
Earth Similarity Index 0.717
Travel time at Voyager 1 speed 686,800 years
Almost certainly tidally locked to its host star given the close orbit

2 siblings around GJ 180

GJ 180 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
GJ 180 b	Sub-Neptune	2.43	6.49	17.133	—	2014
GJ 180 c this	Sub-Neptune	2.41	6.40	24.329	—	2014
GJ 180 d	Sub-Neptune	2.66	7.56	106.300	—	2020

GJ 180 c Planet Profile

Physical Specs

Radius

2.41 R⊕

Radius (Jupiter)

0.215 R♃

Mass

6.40 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.51 g/cm³

Surface Gravity

1.10 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.717

HZ Position Unknown

Controversial No

Discovery

Year 2014

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#1312of 1978

top 66.3%

This planet

2.41R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-143 b 2.41 R⊕ Kepler-343 b 2.41 R⊕ GJ 536 b 2.41 R⊕

Metric	Earth	GJ 180 c	Jupiter
Radius (R⊕)	1.00	2.41	11.21
Mass (M⊕)	1.00	6.40	317.83
Density (g/cm³)	5.51	2.51	1.33
Surface Gravity (g)	1.00	1.10	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	6.400 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HIP

HIP 22762

TIC

TIC 246902275

Gaia DR2

Gaia DR2 2979590513145784192

Gaia DR3

Gaia DR3 2979590513145784192

System

GJ 180

Percentile among Sub-Neptune cohort

Radius 2.410 R⊕ · percentile 33 / cohort 1978

Mass 6.400 M⊕ · percentile 32 / cohort 1978

Orbital period 24.33 d · percentile 68 / cohort 1946

Distance 11.94 pc · percentile 2 / cohort 1975

ESI 0.717 · percentile 94 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

24.329 days

Semi-major axis

0.1290 AU

Eccentricity

0.090

Inclination

— °

Year Length

A year here lasts approximately 24.33 Earth days (6.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1290 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.717

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 b · Sub-Neptune GJ 682 c · Sub-Neptune GJ 160.2 b · Sub-Neptune GJ 422 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 180

Spectral Class

M-type red dwarf

Effective Temperature

3,371 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.413 R☉

Stellar Mass

0.430 M☉

Metallicity [Fe/H]

—

Extended Stellar Properties

Surface gravity (log g)

4.815 dex

Stellar density

8.125 g/cm³

Systemic radial velocity

-15.07 km/s

Distance

11.94 parsec

Light-years 38.95 ly

V-band magnitude

10.91 mag

Voyager-speed travel 686,800 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

83.718 mas

Total Proper Motion

763.062 mas/yr

PM Right Ascension

408.57 mas/yr

PM Declination

-644.46 mas/yr

Galactic Cartesian (pc)

x = 0.271 · y = 0.913 · z = -0.305

Equatorial (J2000)

RA 73.46010° · Dec -17.77619°

Galactic ℓ, b

216.970° · -33.727°

Ecliptic λ, β

69.261° · -40.032°

HTM-20 index

488482743