Key parameters at a glance

A radius of 8.80 Earth radii
A mass of 23.10 Earth masses
Surface gravity around 0.30 g
An orbital period of 143.344 days
Semi-major axis 0.5000 AU
Equilibrium temperature 308 K (35 °C)
Distance from Earth 2,981.79 light-years
Earth Similarity Index 0.351
Travel time at Voyager 1 speed 52,583,805 years

2 siblings around Kepler-30

Kepler-30 d 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-30 b	Sub-Neptune	3.90	11.30	29.334	524	2012
Kepler-30 c	Gas Giant	12.30	640.00	60.323	411	2012
Kepler-30 d this	Neptune-like	8.80	23.10	143.344	308	2012

Kepler-30 d Planet Profile

Physical Specs

Radius

8.80 R⊕

Radius (Jupiter)

0.785 R♃

Mass

23.10 M⊕

Mass (Jupiter)

0.073 M♃

Density

0.19 g/cm³

Surface Gravity

0.30 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.351

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

#100of 574

top 17.2%

This planet

8.80R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

KOI-1783.01 8.86 R⊕ OGLE-2008-BLG-092L b 8.74 R⊕ Kepler-177 c 8.73 R⊕

Metric	Earth	Kepler-30 d	Jupiter
Radius (R⊕)	1.00	8.80	11.21
Mass (M⊕)	1.00	23.10	317.83
Density (g/cm³)	5.51	0.19	1.33
Surface Gravity (g)	1.00	0.30	2.53
Insolation (S⊕)	1.00	1.96	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	23.100 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 399794329

Gaia DR2

Gaia DR2 2100243616248608896

Gaia DR3

Gaia DR3 2100243616248608896

System

Kepler-30

Percentile among Neptune-like cohort

Radius 8.800 R⊕ · percentile 83 / cohort 574

Mass 23.100 M⊕ · percentile 38 / cohort 574

Orbital period 143.34 d · percentile 86 / cohort 524

Distance 914.22 pc · percentile 72 / cohort 572

ESI 0.351 · percentile 64 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

143.344 days

Semi-major axis

0.5000 AU

Eccentricity

0.022

Inclination

89.84 °

Year Length

A year here lasts approximately 143.34 Earth days (39.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.5000 AU.

Transit Fingerprint

Depth

0.830 %

Duration

7.728 h

Impact parameter b

0.380

Rp / R★

0.091300

Transit midpoint (BJD)

2,455,273.5302

Photometric dip

Transit produces a flux drop of 8,300 ppm lasting ≈ 7.73 h.

Extended Orbital Architecture

Planet / star radius ratio

0.091300

Semi-major axis / stellar radius

109.100

Impact parameter (b)

0.380

Transit mid-time (BJD)

2,455,273.5302

Long. of periastron (ω)

-163.00°

Sky-projected obliquity (λ)

4.00°

Angular separation (arcsec)

0.54700

Eq. Temperature

308K

(35 °C)

Insolation (S⊕)

1.96

Earth = 1.00

Earth Similarity (ESI)

0.351

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — liquid water is physically possible with adequate atmospheric pressure.

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

Sanchis Ojeda et al. 2012

Instrument

Kepler CCD Array

Publication

2012-07

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-30

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,498 K — cooler than the Sun (5,778 K)

Estimated Age

2.00 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.950 R☉

Stellar Mass

0.990 M☉

Metallicity [Fe/H]

0.18

Extended Stellar Properties

Surface gravity (log g)

4.770 dex

Stellar density

2.000 g/cm³

Rotational v·sin i

1.94 km/s

Metallicity ratio

[Fe/H]

Distance

914.22 parsec

Light-years 2,981.79 ly

V-band magnitude

15.73 mag

Voyager-speed travel 52,583,805 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

1.066 mas

Total Proper Motion

4.812 mas/yr

PM Right Ascension

0.70 mas/yr

PM Declination

-4.76 mas/yr

Galactic Cartesian (pc)

x = 0.205 · y = -0.750 · z = 0.629

Equatorial (J2000)

RA 285.28365° · Dec 38.94726°

Galactic ℓ, b

69.407° · 14.913°

Ecliptic λ, β

295.065° · 61.063°

HTM-20 index

292778943