Key parameters at a glance

A radius of 1.76 Earth radii
A mass of 3.75 Earth masses
Surface gravity around 1.21 g
An orbital period of 70.698 days
Semi-major axis 0.3148 AU
Equilibrium temperature 417 K (144 °C)
Distance from Earth 1,372.52 light-years
Earth Similarity Index 0.658
Travel time at Voyager 1 speed 24,204,387 years

Kepler-888 b Planet Profile

Physical Specs

Radius

1.76 R⊕

Radius (Jupiter)

0.157 R♃

Mass

3.75 M⊕

Mass (Jupiter)

0.012 M♃

Density

3.78 g/cm³

Surface Gravity

1.21 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.658

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

#315of 1176

top 26.7%

This planet

1.76R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-916 b 1.76 R⊕ G 264-012 c 1.76 R⊕ Kepler-755 b 1.76 R⊕

Metric	Earth	Kepler-888 b	Jupiter
Radius (R⊕)	1.00	1.76	11.21
Mass (M⊕)	1.00	3.75	317.83
Density (g/cm³)	5.51	3.78	1.33
Surface Gravity (g)	1.00	1.21	2.53
Insolation (S⊕)	1.00	7.85	0.037

Star Catalogue Identifiers

TIC

TIC 27531978

Gaia DR2

Gaia DR2 2134932314753757312

Gaia DR3

Gaia DR3 2134932314753757312

System

Kepler-888

Percentile among Super-Earth cohort

Radius 1.760 R⊕ · percentile 73 / cohort 1176

Mass 3.750 M⊕ · percentile 66 / cohort 1176

Orbital period 70.70 d · percentile 98 / cohort 1164

Distance 420.82 pc · percentile 41 / cohort 1171

ESI 0.658 · percentile 83 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

70.698 days

Semi-major axis

0.3148 AU

Eccentricity

0.000

Inclination

89.98 °

Year Length

A year here lasts approximately 70.70 Earth days (19.4% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.3148 AU.

Transit Fingerprint

Depth

0.038 %

Duration

6.624 h

Impact parameter b

0.026

Rp / R★

0.018018

Transit midpoint (BJD)

2,455,021.5703

Photometric dip

Transit produces a flux drop of 383 ppm lasting ≈ 6.62 h.

Extended Orbital Architecture

Planet / star radius ratio

0.018018

Semi-major axis / stellar radius

82.820

Impact parameter (b)

0.026

Transit mid-time (BJD)

2,455,021.5703

Angular separation (arcsec)

0.74800

Eq. Temperature

417K

(144 °C)

Insolation (S⊕)

7.85

Earth = 1.00

Earth Similarity (ESI)

0.658

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-888

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,875 K — hotter than the Sun (5,778 K)

Estimated Age

1.48 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.900 R☉

Stellar Mass

0.970 M☉

Metallicity [Fe/H]

-0.21

Extended Stellar Properties

Surface gravity (log g)

4.520 dex

Stellar density

1.060 g/cm³

Metallicity ratio

[Fe/H]

Distance

420.82 parsec

Light-years 1,372.52 ly

V-band magnitude

13.06 mag

Voyager-speed travel 24,204,387 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

2.348 mas

Total Proper Motion

20.690 mas/yr

PM Right Ascension

16.09 mas/yr

PM Declination

13.01 mas/yr

Galactic Cartesian (pc)

x = 0.278 · y = -0.583 · z = 0.763

Equatorial (J2000)

RA 295.52129° · Dec 49.73868°

Galactic ℓ, b

82.640° · 12.820°

Ecliptic λ, β

320.251° · 68.768°

HTM-20 index

-294941364