Key parameters at a glance

A radius of 1.99 Earth radii
A mass of 4.62 Earth masses
Surface gravity around 1.17 g
An orbital period of 2.032 days
Semi-major axis 0.0326 AU
Equilibrium temperature 1,542 K (1269 °C)
Distance from Earth 4,395.64 light-years
Earth Similarity Index 0.167
Travel time at Voyager 1 speed 77,517,055 years

Kepler-1217 b Planet Profile

Physical Specs

Radius

1.99 R⊕

Radius (Jupiter)

0.178 R♃

Mass

4.62 M⊕

Mass (Jupiter)

0.015 M♃

Density

3.22 g/cm³

Surface Gravity

1.17 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.167

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

#4of 1176

top 0.3%

This planet

1.99R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

K2-62 c 1.99 R⊕ Kepler-136 c 1.99 R⊕ Kepler-243 c 1.99 R⊕

Metric	Earth	Kepler-1217 b	Jupiter
Radius (R⊕)	1.00	1.99	11.21
Mass (M⊕)	1.00	4.62	317.83
Density (g/cm³)	5.51	3.22	1.33
Surface Gravity (g)	1.00	1.17	2.53
Insolation (S⊕)	1.00	1,302.95	0.037

Star Catalogue Identifiers

TIC

TIC 299160628

Gaia DR2

Gaia DR2 2133150418720312832

Gaia DR3

Gaia DR3 2133150418720312832

System

Kepler-1217

Percentile among Super-Earth cohort

Radius 1.990 R⊕ · percentile 98 / cohort 1176

Mass 4.620 M⊕ · percentile 90 / cohort 1176

Orbital period 2.03 d · percentile 12 / cohort 1164

Distance 1,347.71 pc · percentile 92 / cohort 1171

ESI 0.167 · percentile 7 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

2.032 days

Semi-major axis

0.0326 AU

Eccentricity

0.000

Inclination

89.19 °

Year Length

A year here lasts approximately 2.03 Earth days (0.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0326 AU.

Transit Fingerprint

Depth

0.032 %

Duration

1.718 h

Impact parameter b

0.210

Rp / R★

0.016682

Transit midpoint (BJD)

2,454,965.3187

Photometric dip

Transit produces a flux drop of 316 ppm lasting ≈ 1.72 h.

Extended Orbital Architecture

Planet / star radius ratio

0.016682

Semi-major axis / stellar radius

9.353

Impact parameter (b)

0.210

Transit mid-time (BJD)

2,454,965.3187

Angular separation (arcsec)

0.02420

Eq. Temperature

1,542K

(1269 °C)

Insolation (S⊕)

1,302.95

Earth = 1.00

Earth Similarity (ESI)

0.167

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-1217

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,905 K — hotter than the Sun (5,778 K)

Estimated Age

3.80 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.080 R☉

Stellar Mass

1.060 M☉

Metallicity [Fe/H]

0.07

Extended Stellar Properties

Surface gravity (log g)

4.400 dex

Stellar density

3.351 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,347.71 parsec

Light-years 4,395.64 ly

V-band magnitude

15.34 mag

Voyager-speed travel 77,517,055 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.713 mas

Total Proper Motion

2.238 mas/yr

PM Right Ascension

1.89 mas/yr

PM Declination

-1.20 mas/yr

Galactic Cartesian (pc)

x = 0.207 · y = -0.595 · z = 0.776

Equatorial (J2000)

RA 289.18668° · Dec 50.93756°

Galactic ℓ, b

82.018° · 16.992°

Ecliptic λ, β

311.122° · 71.646°

HTM-20 index

228225882