Key parameters at a glance

A radius of 4.90 Earth radii
A mass of 4,385.87 Earth masses
Surface gravity around 182.67 g
An orbital period of 31.331 days
Semi-major axis 0.1910 AU
Equilibrium temperature 481 K (208 °C)
Distance from Earth 3,406.24 light-years
Earth Similarity Index 0.251
Travel time at Voyager 1 speed 60,069,088 years

2 siblings around Kepler-27

Kepler-27 c shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-27 d	Sub-Neptune	2.71	7.78	6.546	810	2021
Kepler-27 b	Neptune-like	4.00	2,895.31	15.335	610	2011
Kepler-27 c this	Neptune-like	4.90	4,385.87	31.331	481	2011

Kepler-27 c Planet Profile

Physical Specs

Radius

4.90 R⊕

Radius (Jupiter)

0.437 R♃

Mass

4,385.87 M⊕

Mass (Jupiter)

13.800 M♃

Density

— g/cm³

Surface Gravity

182.67 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.251

HZ Position Inner

Controversial No

Discovery

Year 2011

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#399of 574

top 69.3%

This planet

4.90R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

HD 219666 b 4.90 R⊕ TOI-5678 b 4.91 R⊕ GJ 328 c 4.91 R⊕

Metric	Earth	Kepler-27 c	Jupiter
Radius (R⊕)	1.00	4.90	11.21
Mass (M⊕)	1.00	4,385.87	317.83
Density (g/cm³)	5.51	—	1.33
Surface Gravity (g)	1.00	182.67	2.53
Insolation (S⊕)	1.00	11.07	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	4,385.870 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 137556626

Gaia DR2

Gaia DR2 2053586321364864640

Gaia DR3

Gaia DR3 2053586321364864640

System

Kepler-27

Percentile among Neptune-like cohort

Radius 4.900 R⊕ · percentile 30 / cohort 574

Mass 4,385.870 M⊕ · percentile 100 / cohort 574

Orbital period 31.33 d · percentile 60 / cohort 524

Distance 1,044.36 pc · percentile 76 / cohort 572

ESI 0.251 · percentile 40 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

31.331 days

Semi-major axis

0.1910 AU

Eccentricity

0.000

Inclination

88.62 °

Year Length

A year here lasts approximately 31.33 Earth days (8.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1910 AU.

Transit Fingerprint

Depth

0.507 %

Duration

4.750 h

Impact parameter b

0.792

Rp / R★

0.073160

Transit midpoint (BJD)

2,454,986.4274

Photometric dip

Transit produces a flux drop of 5,074 ppm lasting ≈ 4.75 h.

Extended Orbital Architecture

Planet / star radius ratio

0.073160

Semi-major axis / stellar radius

30.800

Impact parameter (b)

0.792

Transit mid-time (BJD)

2,454,986.4274

Angular separation (arcsec)

0.18300

Eq. Temperature

481K

(208 °C)

Insolation (S⊕)

11.07

Earth = 1.00

Earth Similarity (ESI)

0.251

0 = alien, 1 = Earth-identical

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

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Transit timing variations

Gravitational interactions from neighbours have been detected.

Discovery Paper

Primary reference

Steffen et al. 2012

Instrument

Kepler CCD Array

Publication

2012-04

Observation locale

Space

Discovery cohort

Planets confirmed in 2011 at Kepler (12 shown).

Kepler-22 b · Sub-Neptune Kepler-20 d · Sub-Neptune Kepler-26 c · Sub-Neptune Kepler-19 c · Sub-Neptune Kepler-26 b · Sub-Neptune Kepler-28 c · Super-Earth Kepler-10 c · Sub-Neptune Kepler-20 f · Rocky Terrestrial Kepler-42 d · Rocky Terrestrial Kepler-16 b · Neptune-like Kepler-28 b · Super-Earth Kepler-34 b · Neptune-like

Host System: Kepler-27

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,400 K — cooler than the Sun (5,778 K)

Estimated Age

1.62 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.590 R☉

Stellar Mass

0.650 M☉

Metallicity [Fe/H]

0.41

Extended Stellar Properties

Surface gravity (log g)

5.400 dex

Stellar density

1.680 g/cm³

Rotational v·sin i

0.60 km/s

Metallicity ratio

[M/H]

Distance

1,044.36 parsec

Light-years 3,406.24 ly

V-band magnitude

15.82 mag

Voyager-speed travel 60,069,088 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

0.930 mas

Total Proper Motion

2.273 mas/yr

PM Right Ascension

2.25 mas/yr

PM Declination

-0.33 mas/yr

Galactic Cartesian (pc)

x = 0.285 · y = -0.698 · z = 0.657

Equatorial (J2000)

RA 292.23676° · Dec 41.08587°

Galactic ℓ, b

73.687° · 10.974°

Ecliptic λ, β

306.984° · 61.700°

HTM-20 index

1762945600