Key parameters at a glance
- A radius of 2.20 Earth radii
- A mass of 102.30 Earth masses
- Surface gravity around 21.14 g
- An orbital period of 7.954 days
- Semi-major axis 0.0740 AU
- Equilibrium temperature 696 K (423 °C)
- Distance from Earth 2,436.15 light-years
- Earth Similarity Index 0.224
- Travel time at Voyager 1 speed 42,961,454 years
- Almost certainly tidally locked to its host star given the close orbit
1 sibling around Kepler-240
Kepler-240 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.
| Planet | Type | Radius (R⊕) | Mass (M⊕) | Period (d) | Eq. T (K) | Year |
|---|---|---|---|---|---|---|
| Kepler-240 b | Super-Earth | 1.37 | 2.45 | 4.144 | 864 | 2014 |
| Kepler-240 c this | Sub-Neptune | 2.20 | 102.30 | 7.954 | 696 | 2014 |
Kepler-240 c Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1673of 1978
top 84.5%
This planet
2.20R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-240 c | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.20 | 11.21 |
| Mass (M⊕) | 1.00 | 102.30 | 317.83 |
| Density (g/cm³) | 5.51 | 52.80 | 1.33 |
| Surface Gravity (g) | 1.00 | 21.14 | 2.53 |
| Insolation (S⊕) | 1.00 | 59.84 | 0.037 |
Alternative Mass Estimates
| Method | Value | Interpretation |
|---|---|---|
| Best measured mass | 102.300 M⊕ | Direct mass measurement (not derived). |
Star Catalogue Identifiers
TIC
TIC 122712446
Gaia DR2
Gaia DR2 2101521042605000832
Gaia DR3
Gaia DR3 2101521042605000832
System
Kepler-240
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 7.95 Earth days (2.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0740 AU.
Transit Fingerprint
Depth
0.096 %
Duration
2.598 h
Impact parameter b
0.360
Rp / R★
0.026448
Transit midpoint (BJD)
2,455,007.6616
Photometric dip
Transit produces a flux drop of 962 ppm lasting ≈ 2.60 h.
Extended Orbital Architecture
Planet / star radius ratio
0.026448
Semi-major axis / stellar radius
23.750
Impact parameter (b)
0.360
Transit mid-time (BJD)
2,455,007.6616
Angular separation (arcsec)
0.09910
Eq. Temperature
696K
(423 °C)
Insolation (S⊕)
59.84
Earth = 1.00
Earth Similarity (ESI)
0.224
0 = alien, 1 = Earth-identical
Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.
Discovery Paper
Primary reference
Rowe et al. 2014Instrument
Kepler CCD Array
Publication
2014-03
Observation locale
Space
Discovery cohort
Planets confirmed in 2014 at Kepler (12 shown).
Host System: Kepler-240
Spectral Class
K-type orange
Effective Temperature
4,985 K — cooler than the Sun (5,778 K)
Estimated Age
1.91 Gyr — younger than the Sun (4.6 Gyr)
Stellar Radius
0.739 R☉
Stellar Mass
0.868 M☉
Metallicity [Fe/H]
0.41
Extended Stellar Properties
Surface gravity (log g)
4.626 dex
Stellar density
1.780 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.311 mas
Total Proper Motion
10.592 mas/yr
PM Right Ascension
-2.32 mas/yr
PM Declination
-10.34 mas/yr
Galactic Cartesian (pc)
x = 0.273 · y = -0.706 · z = 0.653
Equatorial (J2000)
RA 291.15876° · Dec 40.75021°
Galactic ℓ, b
73.013° · 11.556°
Ecliptic λ, β
305.133° · 61.633°
HTM-20 index
1626680490
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