Key parameters at a glance

A radius of 1.22 Earth radii
A mass of 1.98 Earth masses
Surface gravity around 1.33 g
An orbital period of 2.536 days
Semi-major axis 0.0375 AU
Equilibrium temperature 1,671 K (1398 °C)
Distance from Earth 2,825.59 light-years
Earth Similarity Index 0.173
Travel time at Voyager 1 speed 49,829,286 years

2 siblings around Kepler-1311

Kepler-1311 c 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
Kepler-1311 c this	Rocky Terrestrial	1.22	1.98	2.536	1,671	2016
Kepler-1311 b	Rocky Terrestrial	1.24	2.07	11.173	1,019	2016
Kepler-1311 d	Neptune-like	9.66	67.50	197.511	391	2021

Kepler-1311 c Planet Profile

Physical Specs

Radius

1.22 R⊕

Radius (Jupiter)

0.109 R♃

Mass

1.98 M⊕

Mass (Jupiter)

0.006 M♃

Density

5.99 g/cm³

Surface Gravity

1.33 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.173

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#35of 570

top 6.0%

This planet

1.22R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-295 b 1.22 R⊕ Kepler-226 d 1.22 R⊕ Kepler-197 d 1.22 R⊕

Metric	Earth	Kepler-1311 c	Jupiter
Radius (R⊕)	1.00	1.22	11.21
Mass (M⊕)	1.00	1.98	317.83
Density (g/cm³)	5.51	5.99	1.33
Surface Gravity (g)	1.00	1.33	2.53
Insolation (S⊕)	1.00	2,144.55	0.037

Star Catalogue Identifiers

TIC

TIC 159106207

Gaia DR2

Gaia DR2 2102877015319104640

Gaia DR3

Gaia DR3 2102877015319104640

System

Kepler-1311

Percentile among Rocky Terrestrial cohort

Radius 1.220 R⊕ · percentile 92 / cohort 570

Mass 1.980 M⊕ · percentile 83 / cohort 570

Orbital period 2.54 d · percentile 29 / cohort 567

Distance 866.33 pc · percentile 89 / cohort 566

ESI 0.173 · percentile 9 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

2.536 days

Semi-major axis

0.0375 AU

Eccentricity

0.000

Inclination

89.37 °

Year Length

A year here lasts approximately 2.54 Earth days (0.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0375 AU.

Transit Fingerprint

Depth

0.007 %

Duration

3.941 h

Impact parameter b

0.054

Rp / R★

0.007783

Transit midpoint (BJD)

2,454,966.0141

Photometric dip

Transit produces a flux drop of 68 ppm lasting ≈ 3.94 h.

Extended Orbital Architecture

Planet / star radius ratio

0.007783

Semi-major axis / stellar radius

4.921

Impact parameter (b)

0.054

Transit mid-time (BJD)

2,454,966.0141

Angular separation (arcsec)

0.04330

Eq. Temperature

1,671K

(1398 °C)

Insolation (S⊕)

2,144.55

Earth = 1.00

Earth Similarity (ESI)

0.173

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

Discovery Paper

Primary reference

Morton et al. 2016

Instrument

Kepler CCD Array

Publication

2016-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2016 at Kepler (12 shown).

Kepler-1512 b · Rocky Terrestrial Kepler-1410 b · Super-Earth Kepler-560 b · Super-Earth Kepler-1389 b · Super-Earth Kepler-1450 b · Super-Earth Kepler-1544 b · Super-Earth Kepler-1459 b · Super-Earth Kepler-1638 b · Super-Earth Kepler-737 b · Super-Earth Kepler-1185 b · Super-Earth Kepler-1178 b · Rocky Terrestrial Kepler-1040 b · Sub-Neptune

Host System: Kepler-1311

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,748 K — cooler than the Sun (5,778 K)

Estimated Age

7.59 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.400 R☉

Stellar Mass

1.050 M☉

Metallicity [Fe/H]

0.09

Extended Stellar Properties

Surface gravity (log g)

4.160 dex

Stellar density

0.230 g/cm³

Metallicity ratio

[Fe/H]

Distance

866.33 parsec

Light-years 2,825.59 ly

V-band magnitude

13.53 mag

Voyager-speed travel 49,829,286 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.126 mas

Total Proper Motion

7.026 mas/yr

PM Right Ascension

3.20 mas/yr

PM Declination

6.26 mas/yr

Galactic Cartesian (pc)

x = 0.243 · y = -0.679 · z = 0.692

Equatorial (J2000)

RA 289.65126° · Dec 43.82444°

Galactic ℓ, b

75.376° · 13.875°

Ecliptic λ, β

304.885° · 64.901°

HTM-20 index

931493814