Key parameters at a glance

A radius of 2.78 Earth radii
A mass of 8.15 Earth masses
Surface gravity around 1.05 g
An orbital period of 21.359 days
Semi-major axis 0.1539 AU
Equilibrium temperature 691 K (418 °C)
Distance from Earth 4,107.80 light-years
Earth Similarity Index 0.352
Travel time at Voyager 1 speed 72,441,126 years

Kepler-870 b Planet Profile

Physical Specs

Radius

2.78 R⊕

Radius (Jupiter)

0.248 R♃

Mass

8.15 M⊕

Mass (Jupiter)

0.026 M♃

Density

2.08 g/cm³

Surface Gravity

1.05 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.352

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

#768of 1978

top 38.8%

This planet

2.78R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-58 b 2.78 R⊕ Kepler-531 b 2.78 R⊕ K2-284 b 2.78 R⊕

Metric	Earth	Kepler-870 b	Jupiter
Radius (R⊕)	1.00	2.78	11.21
Mass (M⊕)	1.00	8.15	317.83
Density (g/cm³)	5.51	2.08	1.33
Surface Gravity (g)	1.00	1.05	2.53
Insolation (S⊕)	1.00	54.87	0.037

Star Catalogue Identifiers

TIC

TIC 27455225

Gaia DR2

Gaia DR2 2135175478621290624

Gaia DR3

Gaia DR3 2135175478621290624

System

Kepler-870

Percentile among Sub-Neptune cohort

Radius 2.780 R⊕ · percentile 61 / cohort 1978

Mass 8.150 M⊕ · percentile 56 / cohort 1978

Orbital period 21.36 d · percentile 65 / cohort 1946

Distance 1,259.46 pc · percentile 88 / cohort 1975

ESI 0.352 · percentile 41 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

21.359 days

Semi-major axis

0.1539 AU

Eccentricity

0.000

Inclination

89.81 °

Year Length

A year here lasts approximately 21.36 Earth days (5.8% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1539 AU.

Transit Fingerprint

Depth

0.064 %

Duration

5.905 h

Impact parameter b

0.847

Rp / R★

0.024619

Transit midpoint (BJD)

2,454,968.0711

Photometric dip

Transit produces a flux drop of 640 ppm lasting ≈ 5.91 h.

Extended Orbital Architecture

Planet / star radius ratio

0.024619

Semi-major axis / stellar radius

28.560

Impact parameter (b)

0.847

Transit mid-time (BJD)

2,454,968.0711

Angular separation (arcsec)

0.12200

Eq. Temperature

691K

(418 °C)

Insolation (S⊕)

54.87

Earth = 1.00

Earth Similarity (ESI)

0.352

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

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-870

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,857 K — hotter than the Sun (5,778 K)

Estimated Age

3.80 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.020 R☉

Stellar Mass

1.010 M☉

Metallicity [Fe/H]

-0.01

Extended Stellar Properties

Surface gravity (log g)

4.430 dex

Stellar density

0.858 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,259.46 parsec

Light-years 4,107.80 ly

V-band magnitude

15.33 mag

Voyager-speed travel 72,441,126 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.766 mas

Total Proper Motion

10.849 mas/yr

PM Right Ascension

1.65 mas/yr

PM Declination

-10.72 mas/yr

Galactic Cartesian (pc)

x = 0.273 · y = -0.575 · z = 0.771

Equatorial (J2000)

RA 295.40256° · Dec 50.47860°

Galactic ℓ, b

83.282° · 13.223°

Ecliptic λ, β

321.059° · 69.454°

HTM-20 index

-357590666