Key parameters at a glance

A radius of 2.58 Earth radii
A mass of 5.40 Earth masses
Surface gravity around 0.81 g
An orbital period of 5.860 days
Semi-major axis 0.0680 AU
Equilibrium temperature 1,246 K (973 °C)
Distance from Earth 990.63 light-years
Earth Similarity Index 0.184
Travel time at Voyager 1 speed 17,469,708 years

3 siblings around Kepler-65

Kepler-65 c shares its host star with 3 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-65 b	Super-Earth	1.42	2.40	2.155	1,740	2012
Kepler-65 c this	Sub-Neptune	2.58	5.40	5.860	1,246	2012
Kepler-65 d	Super-Earth	1.52	4.14	8.131	1,117	2012
Kepler-65 e	Gas Giant	13.90	260.00	258.800	—	2019

Kepler-65 c Planet Profile

Physical Specs

Radius

2.58 R⊕

Radius (Jupiter)

0.230 R♃

Mass

5.40 M⊕

Mass (Jupiter)

0.017 M♃

Density

1.64 g/cm³

Surface Gravity

0.81 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.184

HZ Position Inner

Controversial No

Discovery

Year 2012

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1057of 1978

top 53.4%

This planet

2.58R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-1018 b 2.58 R⊕ Kepler-169 f 2.58 R⊕ Kepler-461 b 2.58 R⊕

Metric	Earth	Kepler-65 c	Jupiter
Radius (R⊕)	1.00	2.58	11.21
Mass (M⊕)	1.00	5.40	317.83
Density (g/cm³)	5.51	1.64	1.33
Surface Gravity (g)	1.00	0.81	2.53
Insolation (S⊕)	1.00	609.99	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	5.400 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	4.983 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 121731834

Gaia DR2

Gaia DR2 2102119176929154304

Gaia DR3

Gaia DR3 2102119176929154304

System

Kepler-65

Percentile among Sub-Neptune cohort

Radius 2.580 R⊕ · percentile 46 / cohort 1978

Mass 5.400 M⊕ · percentile 14 / cohort 1978

Orbital period 5.86 d · percentile 16 / cohort 1946

Distance 303.73 pc · percentile 35 / cohort 1975

ESI 0.184 · percentile 5 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

5.860 days

Semi-major axis

0.0680 AU

Eccentricity

0.020

Inclination

92.33 °

Year Length

A year here lasts approximately 5.86 Earth days (1.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0680 AU.

Transit Fingerprint

Depth

0.028 %

Duration

3.928 h

Impact parameter b

0.420

Rp / R★

0.016743

Transit midpoint (BJD)

2,454,965.0391

Photometric dip

Transit produces a flux drop of 282 ppm lasting ≈ 3.93 h.

Extended Orbital Architecture

Planet / star radius ratio

0.016743

Semi-major axis / stellar radius

10.309

Impact parameter (b)

0.420

RV semi-amplitude (K)

1.524 m/s

Transit mid-time (BJD)

2,454,965.0391

Angular separation (arcsec)

0.22400

Eq. Temperature

1,246K

(973 °C)

Insolation (S⊕)

609.99

Earth = 1.00

Earth Similarity (ESI)

0.184

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

Detection Signatures

Transit photometry

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

Radial velocity

Stellar wobble has been measured spectroscopically.

Transit timing variations

Gravitational interactions from neighbours have been detected.

Discovery Paper

Primary reference

Chaplin et al. 2013

Instrument

Kepler CCD Array

Publication

2013-04

Observation locale

Space

Discovery cohort

Planets confirmed in 2012 at Kepler (12 shown).

Kepler-54 c · Rocky Terrestrial Kepler-49 c · Sub-Neptune Kepler-55 b · Sub-Neptune Kepler-49 b · Sub-Neptune Kepler-81 c · Sub-Neptune Kepler-55 c · Sub-Neptune Kepler-52 c · Super-Earth Kepler-83 c · Sub-Neptune Kepler-32 d · Sub-Neptune Kepler-83 b · Sub-Neptune Kepler-54 b · Sub-Neptune Kepler-80 c · Sub-Neptune

Host System: Kepler-65

Spectral Class

F-type yellow-white

Effective Temperature

6,211 K — hotter than the Sun (5,778 K)

Estimated Age

2.90 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.410 R☉

Stellar Mass

1.250 M☉

Metallicity [Fe/H]

0.17

Extended Stellar Properties

Surface gravity (log g)

4.232 dex

Stellar density

0.621 g/cm³

Systemic radial velocity

-16.72 km/s

Rotational v·sin i

10.40 km/s

Metallicity ratio

[Fe/H]

Distance

303.73 parsec

Light-years 990.63 ly

V-band magnitude

10.92 mag

Voyager-speed travel 17,469,708 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

3.264 mas

Total Proper Motion

14.222 mas/yr

PM Right Ascension

0.97 mas/yr

PM Declination

-14.19 mas/yr

Galactic Cartesian (pc)

x = 0.241 · y = -0.713 · z = 0.658

Equatorial (J2000)

RA 288.68872° · Dec 41.15111°

Galactic ℓ, b

72.570° · 13.415°

Ecliptic λ, β

301.565° · 62.557°

HTM-20 index

-1442391783