Key parameters at a glance

A radius of 0.98 Earth radii
A mass of 1.30 Earth masses
Surface gravity around 1.36 g
An orbital period of 9.605 days
Semi-major axis 0.0901 AU
Equilibrium temperature 1,052 K (779 °C)
Distance from Earth 470.21 light-years
Earth Similarity Index 0.290
Travel time at Voyager 1 speed 8,292,083 years

3 siblings around Kepler-68

Kepler-68 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-68 b	Sub-Neptune	2.36	8.03	5.399	1,275	2013
Kepler-68 c this	Rocky Terrestrial	0.98	1.30	9.605	1,052	2013
Kepler-68 d	Gas Giant	13.90	267.00	632.620	—	2013
Kepler-68 e	Gas Giant	11.20	86.45	3,455.000	—	2023

Kepler-68 c Planet Profile

Physical Specs

Radius

0.98 R⊕

Radius (Jupiter)

0.087 R♃

Mass

1.30 M⊕

Mass (Jupiter)

0.004 M♃

Density

7.50 g/cm³

Surface Gravity

1.36 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.290

HZ Position Inner

Controversial No

Discovery

Year 2013

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#359of 570

top 62.8%

This planet

0.98R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-220 d 0.98 R⊕ Kepler-1053 b 0.98 R⊕ Kepler-1328 b 0.98 R⊕

Metric	Earth	Kepler-68 c	Jupiter
Radius (R⊕)	1.00	0.98	11.21
Mass (M⊕)	1.00	1.30	317.83
Density (g/cm³)	5.51	7.50	1.33
Surface Gravity (g)	1.00	1.36	2.53
Insolation (S⊕)	1.00	204.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	1.300 M⊕	Direct mass measurement (not derived).
Minimum mass (M sin i)	2.670 M⊕	Lower bound from radial-velocity fitting.

Star Catalogue Identifiers

TIC

TIC 417676622

Gaia DR2

Gaia DR2 2129550445852902656

Gaia DR3

Gaia DR3 2129550445852902656

System

Kepler-68

Percentile among Rocky Terrestrial cohort

Radius 0.979 R⊕ · percentile 37 / cohort 570

Mass 1.300 M⊕ · percentile 50 / cohort 570

Orbital period 9.61 d · percentile 77 / cohort 567

Distance 144.17 pc · percentile 27 / cohort 566

ESI 0.290 · percentile 36 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

9.605 days

Semi-major axis

0.0901 AU

Eccentricity

0.099

Inclination

87.07 °

Year Length

A year here lasts approximately 9.61 Earth days (2.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0901 AU.

Transit Fingerprint

Depth

0.006 %

Duration

3.005 h

Impact parameter b

0.770

Rp / R★

0.006778

Transit midpoint (BJD)

2,454,969.3821

Photometric dip

Transit produces a flux drop of 56 ppm lasting ≈ 3.00 h.

Extended Orbital Architecture

Planet / star radius ratio

0.006778

Semi-major axis / stellar radius

15.680

Impact parameter (b)

0.770

RV semi-amplitude (K)

0.370 m/s

Transit mid-time (BJD)

2,454,969.3821

Long. of periastron (ω)

0.00°

Angular separation (arcsec)

0.62500

Eq. Temperature

1,052K

(779 °C)

Insolation (S⊕)

204.00

Earth = 1.00

Earth Similarity (ESI)

0.290

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.

Discovery Paper

Primary reference

Gilliland et al. 2013

Instrument

Kepler CCD Array

Publication

2013-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2013 at Kepler (12 shown).

Kepler-69 c · Super-Earth Kepler-61 b · Sub-Neptune Kepler-62 e · Super-Earth KOI-351 f · Sub-Neptune Kepler-62 f · Super-Earth KOI-351 e · Sub-Neptune Kepler-1704 b · Gas Giant Kepler-37 d · Sub-Neptune Kepler-282 e · Sub-Neptune KOI-351 h · Gas Giant KOI-351 d · Sub-Neptune Kepler-114 c · Super-Earth

Host System: Kepler-68

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,847 K — hotter than the Sun (5,778 K)

Estimated Age

6.84 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.256 R☉

Stellar Mass

1.057 M☉

Metallicity [Fe/H]

0.11

Extended Stellar Properties

Surface gravity (log g)

4.281 dex

Stellar density

0.790 g/cm³

Systemic radial velocity

-20.90 km/s

Rotational v·sin i

0.50 km/s

Metallicity ratio

[Fe/H]

Distance

144.17 parsec

Light-years 470.21 ly

V-band magnitude

10.08 mag

Voyager-speed travel 8,292,083 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

6.908 mas

Total Proper Motion

12.750 mas/yr

PM Right Ascension

-7.33 mas/yr

PM Declination

-10.43 mas/yr

Galactic Cartesian (pc)

x = 0.235 · y = -0.612 · z = 0.755

Equatorial (J2000)

RA 291.03231° · Dec 49.04021°

Galactic ℓ, b

80.691° · 15.154°

Ecliptic λ, β

312.030° · 69.429°

HTM-20 index

861394382