Key parameters at a glance
- A radius of 2.26 Earth radii
- A mass of 5.73 Earth masses
- Surface gravity around 1.12 g
- An orbital period of 13.628 days
- Semi-major axis 0.1039 AU
- Equilibrium temperature 639 K (366 °C)
- Distance from Earth 2,242.70 light-years
- Earth Similarity Index 0.411
- Travel time at Voyager 1 speed 39,549,970 years
- Almost certainly tidally locked to its host star given the close orbit
Kepler-1242 b Planet Profile
Physical Specs
Classification
Planet Type
Sub-Neptune
Discovery
Size rank in cohort
Rank by radius
#1572of 1978
top 79.4%
This planet
2.26R⊕
Sub-Neptune median
2.71R⊕
Nearest-size peers
| Metric | Earth | Kepler-1242 b | Jupiter |
|---|---|---|---|
| Radius (R⊕) | 1.00 | 2.26 | 11.21 |
| Mass (M⊕) | 1.00 | 5.73 | 317.83 |
| Density (g/cm³) | 5.51 | 2.73 | 1.33 |
| Surface Gravity (g) | 1.00 | 1.12 | 2.53 |
| Insolation (S⊕) | 1.00 | 29.00 | 0.037 |
Star Catalogue Identifiers
TIC
TIC 120317833
Gaia DR2
Gaia DR2 2104031227648002944
Gaia DR3
Gaia DR3 2104031227648002944
System
Kepler-1242
Percentile among Sub-Neptune cohort
Orbit & Habitability
Orbital Dynamics
Year Length
A year here lasts approximately 13.63 Earth days (3.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1039 AU.
Transit Fingerprint
Depth
0.091 %
Duration
3.047 h
Impact parameter b
0.236
Rp / R★
0.027952
Transit midpoint (BJD)
2,454,968.4505
Photometric dip
Transit produces a flux drop of 913 ppm lasting ≈ 3.05 h.
Extended Orbital Architecture
Planet / star radius ratio
0.027952
Semi-major axis / stellar radius
34.190
Impact parameter (b)
0.236
Transit mid-time (BJD)
2,454,968.4505
Angular separation (arcsec)
0.15100
Eq. Temperature
639K
(366 °C)
Insolation (S⊕)
29.00
Earth = 1.00
Earth Similarity (ESI)
0.411
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
Morton et al. 2016Instrument
Kepler CCD Array
Publication
2016-05
Observation locale
Space
Discovery cohort
Planets confirmed in 2016 at Kepler (12 shown).
Host System: Kepler-1242
Spectral Class
K-type orange
Effective Temperature
4,895 K — cooler than the Sun (5,778 K)
Estimated Age
5.62 Gyr — older than the Sun (4.6 Gyr)
Stellar Radius
0.740 R☉
Stellar Mass
0.770 M☉
Metallicity [Fe/H]
-0.05
Extended Stellar Properties
Surface gravity (log g)
4.600 dex
Stellar density
4.072 g/cm³
Metallicity ratio
[Fe/H]
Multi-band Host Photometry — 16 bands
Astrometric Data
Parallax
1.426 mas
Total Proper Motion
8.037 mas/yr
PM Right Ascension
-0.90 mas/yr
PM Declination
-7.99 mas/yr
Galactic Cartesian (pc)
x = 0.190 · y = -0.728 · z = 0.659
Equatorial (J2000)
RA 284.60622° · Dec 41.19634°
Galactic ℓ, b
71.357° · 16.255°
Ecliptic λ, β
295.043° · 63.371°
HTM-20 index
1889642211
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Kepler-1388 c
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Radius 2.26 R⊕ · 661.9 ly