Key parameters at a glance

A radius of 3.71 Earth radii
A mass of 13.30 Earth masses
Surface gravity around 0.97 g
An orbital period of 14.440 days
Semi-major axis 0.0876 AU
Distance from Earth 57.50 light-years
Earth Similarity Index 0.568
Travel time at Voyager 1 speed 1,014,018 years
Almost certainly tidally locked to its host star given the close orbit

LSPM J2116+0234 b Planet Profile

Physical Specs

Radius

3.71 R⊕

Radius (Jupiter)

0.331 R♃

Mass

13.30 M⊕

Mass (Jupiter)

0.042 M♃

Density

1.43 g/cm³

Surface Gravity

0.97 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.568

HZ Position Unknown

Controversial No

Discovery

Year 2019

Method Radial Velocity

Facility Calar Alto Observatory

Telescope 3.5 m telescope

Size rank in cohort

Rank by radius

#85of 1978

top 4.2%

This planet

3.71R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

HD 56414 b 3.71 R⊕ TOI-7009 b 3.71 R⊕ Kepler-146 b 3.71 R⊕

Metric	Earth	LSPM J2116+0234 b	Jupiter
Radius (R⊕)	1.00	3.71	11.21
Mass (M⊕)	1.00	13.30	317.83
Density (g/cm³)	5.51	1.43	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)	13.300 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 387518186

Gaia DR2

Gaia DR2 2692455319291894400

Gaia DR3

Gaia DR3 2692455319291894400

System

LSPM J2116+0234

Percentile among Sub-Neptune cohort

Radius 3.710 R⊕ · percentile 96 / cohort 1978

Mass 13.300 M⊕ · percentile 88 / cohort 1978

Orbital period 14.44 d · percentile 49 / cohort 1946

Distance 17.63 pc · percentile 4 / cohort 1975

ESI 0.568 · percentile 79 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

14.440 days

Semi-major axis

0.0876 AU

Eccentricity

0.183

Inclination

— °

Year Length

A year here lasts approximately 14.44 Earth days (4.0% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0876 AU.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.568

0 = alien, 1 = Earth-identical

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

Discovery Paper

Primary reference

Lalitha et al. 2019

Instrument

CARMENES

Publication

2019-07

Observation locale

Ground

Discovery cohort

Planets confirmed in 2019 at Calar Alto Observatory (4 shown).

Teegarden's Star b · Rocky Terrestrial Teegarden's Star c · Rocky Terrestrial GJ 4276 b · Neptune-like GJ 3512 b · Gas Giant

Host System: LSPM J2116+0234

Spectral Class

M-type red dwarf

Effective Temperature

3,475 K — cooler than the Sun (5,778 K)

Estimated Age

2.00 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.431 R☉

Stellar Mass

0.430 M☉

Metallicity [Fe/H]

-0.05

Extended Stellar Properties

Surface gravity (log g)

4.950 dex

Stellar density

7.518 g/cm³

Rotational v·sin i

2.00 km/s

Rotation period

42.00 days

Metallicity ratio

[Fe/H]

Distance

17.63 parsec

Light-years 57.50 ly

V-band magnitude

11.96 mag

Voyager-speed travel 1,014,018 yr

Multi-band Host Photometry — 11 bands

Astrometric Data

Parallax

56.694 mas

Total Proper Motion

250.683 mas/yr

PM Right Ascension

247.52 mas/yr

PM Declination

-39.68 mas/yr

Galactic Cartesian (pc)

x = 0.755 · y = -0.654 · z = 0.045

Equatorial (J2000)

RA 319.11475° · Dec 2.58077°

Galactic ℓ, b

53.946° · -30.349°

Ecliptic λ, β

322.378° · 17.542°

HTM-20 index

-816576767