Key parameters at a glance

A radius of 9.03 Earth radii
A mass of 60.20 Earth masses
Surface gravity around 0.74 g
An orbital period of 3.990 days
Semi-major axis 0.0493 AU
Equilibrium temperature 1,124 K (851 °C)
Distance from Earth 4,841.66 light-years
Earth Similarity Index 0.124
Travel time at Voyager 1 speed 85,382,587 years

Kepler-817 b Planet Profile

Physical Specs

Radius

9.03 R⊕

Radius (Jupiter)

0.806 R♃

Mass

60.20 M⊕

Mass (Jupiter)

0.189 M♃

Density

0.45 g/cm³

Surface Gravity

0.74 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.124

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

#87of 574

top 15.0%

This planet

9.03R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

HD 45364 b 9.03 R⊕ KMT-2018-BLG-0748L b 9.01 R⊕ OGLE-2011-BLG-0173L b 9.01 R⊕

Metric	Earth	Kepler-817 b	Jupiter
Radius (R⊕)	1.00	9.03	11.21
Mass (M⊕)	1.00	60.20	317.83
Density (g/cm³)	5.51	0.45	1.33
Surface Gravity (g)	1.00	0.74	2.53
Insolation (S⊕)	1.00	550.20	0.037

Star Catalogue Identifiers

TIC

TIC 184299435

Gaia DR2

Gaia DR2 2073195870740245504

Gaia DR3

Gaia DR3 2073195870740245504

System

Kepler-817

Percentile among Neptune-like cohort

Radius 9.030 R⊕ · percentile 85 / cohort 574

Mass 60.200 M⊕ · percentile 78 / cohort 574

Orbital period 3.99 d · percentile 12 / cohort 524

Distance 1,484.46 pc · percentile 84 / cohort 572

ESI 0.124 · percentile 6 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

3.990 days

Semi-major axis

0.0493 AU

Eccentricity

0.000

Inclination

87.09 °

Year Length

A year here lasts approximately 3.99 Earth days (1.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0493 AU.

Transit Fingerprint

Depth

0.615 %

Duration

2.427 h

Impact parameter b

0.733

Rp / R★

0.080475

Transit midpoint (BJD)

2,455,188.8407

Photometric dip

Transit produces a flux drop of 6,155 ppm lasting ≈ 2.43 h.

Extended Orbital Architecture

Planet / star radius ratio

0.080475

Semi-major axis / stellar radius

9.600

Impact parameter (b)

0.733

Transit mid-time (BJD)

2,455,188.8407

Angular separation (arcsec)

0.03320

Eq. Temperature

1,124K

(851 °C)

Insolation (S⊕)

550.20

Earth = 1.00

Earth Similarity (ESI)

0.124

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-817

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,861 K — hotter than the Sun (5,778 K)

Estimated Age

3.55 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.030 R☉

Stellar Mass

1.030 M☉

Metallicity [Fe/H]

0.02

Extended Stellar Properties

Surface gravity (log g)

4.420 dex

Stellar density

1.784 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,484.46 parsec

Light-years 4,841.66 ly

V-band magnitude

15.97 mag

Voyager-speed travel 85,382,587 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.647 mas

Total Proper Motion

4.414 mas/yr

PM Right Ascension

-3.58 mas/yr

PM Declination

-2.59 mas/yr

Galactic Cartesian (pc)

x = 0.341 · y = -0.696 · z = 0.632

Equatorial (J2000)

RA 296.08185° · Dec 39.16161°

Galactic ℓ, b

73.354° · 7.476°

Ecliptic λ, β

311.317° · 58.916°

HTM-20 index

-1163348418