Key parameters at a glance

A radius of 1.04 Earth radii
A mass of 1.11 Earth masses
Surface gravity around 1.03 g
An orbital period of 3.207 days
Semi-major axis 0.0210 AU
Distance from Earth 11.98 light-years
Earth Similarity Index 0.990
Travel time at Voyager 1 speed 211,250 years
Almost certainly tidally locked to its host star given the close orbit

2 siblings around GJ 1061

GJ 1061 b 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 1061 b this	Rocky Terrestrial	1.04	1.11	3.207	—	2020
GJ 1061 c	Rocky Terrestrial	1.19	1.81	6.682	—	2020
GJ 1061 d	Rocky Terrestrial	1.16	1.67	13.066	—	2020

GJ 1061 b Planet Profile

Physical Specs

Radius

1.04 R⊕

Radius (Jupiter)

0.093 R♃

Mass

1.11 M⊕

Mass (Jupiter)

0.003 M♃

Density

5.42 g/cm³

Surface Gravity

1.03 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.990

HZ Position Inner

Controversial No

Discovery

Year 2020

Method Radial Velocity

Facility La Silla Observatory

Telescope 3.6 m ESO Telescope

Size rank in cohort

Rank by radius

#288of 570

top 50.4%

This planet

1.04R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-1409 b 1.04 R⊕ EPIC 201841433 b 1.04 R⊕ Kepler-1578 b 1.04 R⊕

Metric	Earth	GJ 1061 b	Jupiter
Radius (R⊕)	1.00	1.04	11.21
Mass (M⊕)	1.00	1.11	317.83
Density (g/cm³)	5.51	5.42	1.33
Surface Gravity (g)	1.00	1.03	2.53
Insolation (S⊕)	1.00	3.80	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	1.110 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	1.370 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 79611981

Gaia DR2

Gaia DR2 4848140361962951552

Gaia DR3

Gaia DR3 4848140361962951552

System

GJ 1061

Percentile among Rocky Terrestrial cohort

Radius 1.040 R⊕ · percentile 48 / cohort 570

Mass 1.110 M⊕ · percentile 43 / cohort 570

Orbital period 3.21 d · percentile 36 / cohort 567

Distance 3.67 pc · percentile 1 / cohort 566

ESI 0.990 · percentile 98 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

3.207 days

Semi-major axis

0.0210 AU

Eccentricity

0.050

Inclination

77.00 °

Year Length

A year here lasts approximately 3.21 Earth days (0.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0210 AU.

Eq. Temperature

—

Insolation (S⊕)

3.80

Earth = 1.00

Earth Similarity (ESI)

0.990

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water). Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Dreizler et al. 2020

Instrument

HARPS Spectrograph

Publication

2020-03

Observation locale

Ground

Discovery cohort

Planets confirmed in 2020 at La Silla Observatory (4 shown).

GJ 1061 d · Rocky Terrestrial GJ 1061 c · Rocky Terrestrial GJ 887 c · Sub-Neptune GJ 887 b · Super-Earth

Host System: GJ 1061

Spectral Class

M-type red dwarf

Effective Temperature

2,953 K — cooler than the Sun (5,778 K)

Estimated Age

7.00 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.156 R☉

Stellar Mass

0.120 M☉

Metallicity [Fe/H]

-0.08

Extended Stellar Properties

Surface gravity (log g)

5.159 dex

Stellar density

47.562 g/cm³

Systemic radial velocity

1.49 km/s

Rotational v·sin i

2.50 km/s

Rotation period

125.00 days

Metallicity ratio

[Fe/H]

Distance

3.67 parsec

Light-years 11.98 ly

V-band magnitude

12.70 mag

Voyager-speed travel 211,250 yr

Multi-band Host Photometry — 10 bands

Astrometric Data

Parallax

272.245 mas

Total Proper Motion

833.716 mas/yr

PM Right Ascension

745.29 mas/yr

PM Declination

-373.67 mas/yr

Galactic Cartesian (pc)

x = 0.419 · y = 0.577 · z = -0.701

Equatorial (J2000)

RA 54.00325° · Dec -44.51431°

Galactic ℓ, b

251.871° · -52.901°

Ecliptic λ, β

30.856° · -60.776°

HTM-20 index

1854862311