Finding Earth 2.0
Kepler-1649

Kepler-1649 c

Rank #6 of the ranked catalogue · Discovered by Transit in 2020

HZ 96%inferred

0.774

Earth-2.0 index

rank #6

0.887

Earth Similarity Index

0.809–0.930 (68% CI)

96%

Conservative HZ probability

1.06 R⊕

Radius

mass: inferred_mass_radius

At a glance

Kepler-1649 lies 300.69 light-years (92.191 pc) from the Sun. Kepler-1649 is the host star with 0.198× the Sun's mass and 0.232× its radius (effective temperature 3240 K, versus the Sun's 5772 K). It is a single star hosting 2 known planets. Kepler-1649 c is 1.06× Earth's radius, an estimated 1.2× Earth's mass, inferred from its radius rather than measured, completing one orbit every 19.5 days at 0.0649 AU. It receives about 0.75× the flux Earth gets from the Sun, for an equilibrium temperature near 237 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
Radius1.060 R⊕+0.150 / -0.100
Mass1.200 M⊕inferredNOT measured. Predicted from the radius by a mass-radius relation, so it carries no information beyond the radius.
Bulk density5.540 g/cm³source: catalogue
Escape velocity11.90 km/s
Orbital period19.5353 days
Semi-major axis0.06490 au
Eccentricity0.000
Incident flux0.750 S⊕source: catalogue
Equilibrium temperature236.6 KBond albedo assumed: 0.306. Equilibrium temperature excludes greenhouse warming by construction. Earth's is 254 K against a 288 K surface.
Host star
NameKepler-1649
Spectral typeM
Effective temperature3240 K
Radius0.232 R☉
Mass0.198 M☉
Luminosity10^-2.287 L☉
Metallicity [Fe/H]-0.150
Age
Distance92.2 pc / 300.7 ly
Multiplicity1 star(s), 2 known planet(s)
Gaia DR3 cross-check
Parallax distance92.76 pc0.61% vs. archive-adopted distance
RUWE1.077
Habitable zone
Boundary modelKopparapu et al. (2013), ApJ 765, 131, with the 2013 erratum coefficients
BoundaryS_eff (Earth units)
recent venus1.5095
runaway greenhouse0.8686
moist greenhouse0.8622
maximum greenhouse0.2378
early mars0.2118
Atmospheric spectroscopy

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

Transit analysis
fit not validated

Fitted depth disagrees with the published value. In a multi-planet system this usually means the fold is contaminated by other planets' transits rather than isolating the target. This fit is NOT reported as a measurement.

Radial-velocity analysis

Not requested for this build.

Measurement sources
ParameterValueSource
Planet radius1.0600Vanderburg et al. 2020
Planet mass1.2000archive-calculated (not a publication)
Orbital period19.5353Vanderburg et al. 2020
Semi-major axis0.0649Q1-Q17 DR25 KOI Table
Incident flux0.7500Vanderburg et al. 2020
Equilibrium temperature234.0000Vanderburg et al. 2020
Bulk density5.5400archive-calculated (not a publication)
Orbital eccentricity0.0000Q1-Q17 DR25 KOI Table
Stellar effective temperature3240.0000Vanderburg et al. 2020
Stellar radius0.2317Vanderburg et al. 2020
Stellar mass0.1977Vanderburg et al. 2020
Stellar luminosity-2.2873Vanderburg et al. 2020
Stellar metallicity-0.1500Vanderburg et al. 2020
System distance92.1913TICv8

Component scores

Earth similarity

0.887

Conservative habitability

0.898

Observational confidence

0.502

Characterisation potential

0.428

Evidence

Independent references
3
Published parameter sets
3
Composite parameter sources
4 · mixed
Default-solution coverage
67%
Composite ↔ default difference
0% median
Uncertainty coverage
67%
Discovery method
Transit
Discovery year
2020

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

Observability

TSM
1.92
RV semi-amplitude (expected)
0.840 m/s
Transit-time σ at 2030
52.5 min
Max angular separation
0.70 mas
Reflected-light contrast
4.63e-8

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

Identifiers

system_name
Kepler-1649

Other planets in this system

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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.