Key parameters at a glance

A radius of 2.61 Earth radii
A mass of 7.32 Earth masses
Surface gravity around 1.07 g
An orbital period of 18.871 days
Semi-major axis 0.1401 AU
Equilibrium temperature 701 K (428 °C)
Distance from Earth 3,328.52 light-years
Earth Similarity Index 0.356
Travel time at Voyager 1 speed 58,698,444 years

Kepler-1187 b Planet Profile

Physical Specs

Radius

2.61 R⊕

Radius (Jupiter)

0.233 R♃

Mass

7.32 M⊕

Mass (Jupiter)

0.023 M♃

Density

2.26 g/cm³

Surface Gravity

1.07 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.356

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

#999of 1978

top 50.5%

This planet

2.61R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-214 b 2.61 R⊕ GJ 143 b 2.61 R⊕ TOI-1422 c 2.61 R⊕

Metric	Earth	Kepler-1187 b	Jupiter
Radius (R⊕)	1.00	2.61	11.21
Mass (M⊕)	1.00	7.32	317.83
Density (g/cm³)	5.51	2.26	1.33
Surface Gravity (g)	1.00	1.07	2.53
Insolation (S⊕)	1.00	72.96	0.037

Star Catalogue Identifiers

TIC

TIC 121021644

Gaia DR2

Gaia DR2 2099219867845754752

Gaia DR3

Gaia DR3 2099219867845754752

System

Kepler-1187

Percentile among Sub-Neptune cohort

Radius 2.610 R⊕ · percentile 49 / cohort 1978

Mass 7.320 M⊕ · percentile 45 / cohort 1978

Orbital period 18.87 d · percentile 60 / cohort 1946

Distance 1,020.53 pc · percentile 79 / cohort 1975

ESI 0.356 · percentile 42 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

18.871 days

Semi-major axis

0.1401 AU

Eccentricity

0.000

Inclination

87.72 °

Year Length

A year here lasts approximately 18.87 Earth days (5.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1401 AU.

Transit Fingerprint

Depth

0.060 %

Duration

3.248 h

Impact parameter b

0.089

Rp / R★

0.022439

Transit midpoint (BJD)

2,454,976.9552

Photometric dip

Transit produces a flux drop of 596 ppm lasting ≈ 3.25 h.

Extended Orbital Architecture

Planet / star radius ratio

0.022439

Semi-major axis / stellar radius

45.220

Impact parameter (b)

0.089

Transit mid-time (BJD)

2,454,976.9552

Angular separation (arcsec)

0.13700

Eq. Temperature

701K

(428 °C)

Insolation (S⊕)

72.96

Earth = 1.00

Earth Similarity (ESI)

0.356

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-1187

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,975 K — hotter than the Sun (5,778 K)

Estimated Age

3.39 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.090 R☉

Stellar Mass

1.060 M☉

Metallicity [Fe/H]

-0.01

Extended Stellar Properties

Surface gravity (log g)

4.390 dex

Stellar density

4.911 g/cm³

Metallicity ratio

[Fe/H]

Distance

1,020.53 parsec

Light-years 3,328.52 ly

V-band magnitude

14.73 mag

Voyager-speed travel 58,698,444 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

0.952 mas

Total Proper Motion

8.077 mas/yr

PM Right Ascension

1.15 mas/yr

PM Declination

-7.99 mas/yr

Galactic Cartesian (pc)

x = 0.228 · y = -0.751 · z = 0.620

Equatorial (J2000)

RA 286.89200° · Dec 38.31850°

Galactic ℓ, b

69.331° · 13.510°

Ecliptic λ, β

297.272° · 60.168°

HTM-20 index

692352599