Key parameters at a glance

A radius of 3.66 Earth radii
A mass of 13.00 Earth masses
Surface gravity around 0.97 g
An orbital period of 15.819 days
Semi-major axis 0.1010 AU
Distance from Earth 76.99 light-years
Earth Similarity Index 0.573
Travel time at Voyager 1 speed 1,357,772 years
Almost certainly tidally locked to its host star given the close orbit

GJ 27.1 b Planet Profile

Physical Specs

Radius

3.66 R⊕

Radius (Jupiter)

0.327 R♃

Mass

13.00 M⊕

Mass (Jupiter)

0.041 M♃

Density

1.46 g/cm³

Surface Gravity

0.97 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.573

HZ Position Unknown

Controversial No

Discovery

Year 2014

Method Radial Velocity

Facility Multiple Observatories

Telescope Multiple Telescopes

Size rank in cohort

Rank by radius

#107of 1978

top 5.4%

This planet

3.66R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

TOI-1691 b 3.66 R⊕ TOI-1130 b 3.66 R⊕ HD 211970 b 3.66 R⊕

Metric	Earth	GJ 27.1 b	Jupiter
Radius (R⊕)	1.00	3.66	11.21
Mass (M⊕)	1.00	13.00	317.83
Density (g/cm³)	5.51	1.46	1.33
Surface Gravity (g)	1.00	0.97	2.53
Insolation (S⊕)	1.00	—	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Minimum mass (M sin i)	13.000 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

HIP

HIP 3143

TIC

TIC 80417903

Gaia DR2

Gaia DR2 4980466929964496128

Gaia DR3

Gaia DR3 4980466929965023104

System

GJ 27.1

Percentile among Sub-Neptune cohort

Radius 3.660 R⊕ · percentile 94 / cohort 1978

Mass 13.000 M⊕ · percentile 87 / cohort 1978

Orbital period 15.82 d · percentile 53 / cohort 1946

Distance 23.61 pc · percentile 6 / cohort 1975

ESI 0.573 · percentile 79 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

15.819 days

Semi-major axis

0.1010 AU

Eccentricity

0.080

Inclination

— °

Year Length

A year here lasts approximately 15.82 Earth days (4.3% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1010 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.573

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 422 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 27.1

Spectral Class

M-type red dwarf

Effective Temperature

3,542 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.519 R☉

Stellar Mass

0.530 M☉

Metallicity [Fe/H]

—

Extended Stellar Properties

Surface gravity (log g)

4.721 dex

Stellar density

5.211 g/cm³

Systemic radial velocity

11.85 km/s

Distance

23.61 parsec

Light-years 76.99 ly

V-band magnitude

11.45 mag

Voyager-speed travel 1,357,772 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

42.333 mas

Total Proper Motion

530.574 mas/yr

PM Right Ascension

482.47 mas/yr

PM Declination

-220.76 mas/yr

Galactic Cartesian (pc)

x = 0.705 · y = 0.124 · z = -0.698

Equatorial (J2000)

RA 9.99800° · Dec -44.25417°

Galactic ℓ, b

309.846° · -72.720°

Ecliptic λ, β

346.946° · -43.608°

HTM-20 index

-845860711