Finding Earth 2.0
GJ 1061 · M5.5 V

GJ 1061 d

Rank #2 of the ranked catalogue · Discovered by Radial Velocity in 2020

HZ 100%measured

0.875

Earth-2.0 index

rank #2

0.874

Earth Similarity Index

0.842–0.902 (68% CI)

100%

Conservative HZ probability

1.16 R⊕

Radius

mass: measured

At a glance

GJ 1061 lies 11.98 light-years (3.673 pc) from the Sun. GJ 1061 is a M5.5 V star with 0.12× the Sun's mass and 0.156× its radius (effective temperature 2953 K, versus the Sun's 5772 K). It is a single star hosting 3 known planets. GJ 1061 d is 1.16× Earth's radius, 1.67× Earth's mass, directly measured, completing one orbit every 13.1 days at 0.054 AU, on a mildly eccentric orbit (e = 0.04). It receives about 0.6× the flux Earth gets from the Sun, for an equilibrium temperature near 224 K (Earth's is 254 K).

Orbit and habitable-zone boundaries computed in Python from this system’s actual parameters. Sizes and the overall scale are compressed for visibility, not literal; green = conservative HZ, gold = optimistic HZ.

Planet parameters
Radius1.160 R⊕
Mass1.670 M⊕measuredA directly measured dynamical mass.
Bulk density5.880 g/cm³source: catalogue
Escape velocity13.42 km/s
Orbital period13.0660 days
Semi-major axis0.05400 au
Eccentricity0.040
Incident flux0.600 S⊕source: catalogue
Equilibrium temperature223.7 KBond albedo assumed: 0.306. Equilibrium temperature excludes greenhouse warming by construction. Earth's is 254 K against a 288 K surface.
Host star
NameGJ 1061
Spectral typeM5.5 V
Effective temperature2953 K
Radius0.156 R☉
Mass0.120 M☉
Luminosity10^-2.770 L☉
Metallicity [Fe/H]-0.080
Age7.00 Gyr
Distance3.7 pc / 12.0 ly
Multiplicity1 star(s), 3 known planet(s)
Gaia DR3 cross-check
Parallax distance3.67 pc0.04% vs. archive-adopted distance
RUWE1.192
Habitable zone
Boundary modelKopparapu et al. (2013), ApJ 765, 131, with the 2013 erratum coefficients
BoundaryS_eff (Earth units)
recent venus1.4944
runaway greenhouse0.8638
moist greenhouse0.8536
maximum greenhouse0.2304
early mars0.2035
Atmospheric spectroscopy

No published transmission spectrum exists for this planet in the NASA Exoplanet Archive.

Transit analysis

Planet is not flagged as transiting; a light curve cannot show a transit.

Radial-velocity analysis
Measurements185baseline 15.3 yr across 3 instrument(s)
Activity coincidences14RV periodogram peaks matching a stellar-activity indicator period
Fitted semi-amplitude1.75 ± 0.22 m/sM sin i = 1.56 M⊕
Measurement sources
ParameterValueSource
Planet radius1.1600archive-calculated (not a publication)
Planet mass1.6700Dreizler et al. 2025
Orbital period13.0660Dreizler et al. 2025
Semi-major axis0.0540Dreizler et al. 2025
Incident flux0.6000Dreizler et al. 2020
Equilibrium temperature242.0300archive-calculated (not a publication)
Bulk density5.8800archive-calculated (not a publication)
Orbital eccentricity0.0400Dreizler et al. 2025
Stellar effective temperature2953.0000Dreizler et al. 2025
Stellar radius0.1560Dreizler et al. 2025
Stellar mass0.1200Dreizler et al. 2025
Stellar luminosity-2.7696Dreizler et al. 2025
Stellar metallicity-0.0800Dreizler et al. 2025
Stellar age7.0000Dreizler et al. 2025
System distance3.6728TICv8

Component scores

Earth similarity

0.874

Conservative habitability

0.896

Observational confidence

0.846

Characterisation potential

Evidence

Independent references
2
Published parameter sets
2
Composite parameter sources
4 · mixed
Default-solution coverage
67%
Composite ↔ default difference
0% median
Uncertainty coverage
83%
Discovery method
Radial Velocity
Discovery year
2020

The archive composite selects values from multiple publications. This is disclosed separately and is not automatically penalised.

Observability

TSM
n/a (non-transiting)
RV semi-amplitude (expected)
1.865 m/s
Transit-time σ at 2030
Max angular separation
14.70 mas
Reflected-light contrast
8.01e-8

Follow-up lanes are diagnostics, not ranking inputs. Reflected light assumes Ag = 0.30 and Lambertian quadrature.

Identifiers

system_name
GJ 1061

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Any rendering of this world is a scientifically informed visualisation, not an image. No exoplanet has been imaged at surface resolution. Surface and cloud appearance are illustrative of a physically plausible class, not observations.