Confirmed Exoplanet Discovered 2014

Kepler-305 d

A sub-neptune orbiting the k-type orange Kepler-305, located approximately 2,832.6 light-years from Earth.

Key parameters at a glance

  • A radius of 2.76 Earth radii
  • A mass of 6.20 Earth masses
  • Surface gravity around 0.81 g
  • An orbital period of 16.740 days
  • Semi-major axis 0.1209 AU
  • Equilibrium temperature 576 K (303 °C)
  • Distance from Earth 2,832.59 light-years
  • Earth Similarity Index 0.405
  • Travel time at Voyager 1 speed 49,952,719 years
  • Almost certainly tidally locked to its host star given the close orbit

3 siblings around Kepler-305

Kepler-305 d 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-305 e Super-Earth 1.79 3.87 3.205 1,000 2020
Kepler-305 b Sub-Neptune 3.60 10.50 5.487 836 2013
Kepler-305 c Sub-Neptune 3.30 6.00 8.291 728 2013
Kepler-305 d this Sub-Neptune 2.76 6.20 16.740 576 2014

Kepler-305 d Planet Profile

Physical Specs

Radius
2.76 R⊕
Radius (Jupiter)
0.246 R♃
Mass
6.20 M⊕
Mass (Jupiter)
0.020 M♃
Density
1.63 g/cm³
Surface Gravity
0.81 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.405
HZ Position Inner
Controversial No

Discovery

Year 2014
Method Transit
Facility Kepler
Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#794of 1978

top 40.1%

This planet

2.76R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-819 b 2.76 R⊕ Kepler-172 e 2.76 R⊕ Kepler-1458 b 2.76 R⊕
Metric Earth Kepler-305 d Jupiter
Radius (R⊕)1.002.7611.21
Mass (M⊕)1.006.20317.83
Density (g/cm³)5.511.631.33
Surface Gravity (g)1.000.812.53
Insolation (S⊕)1.0025.520.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 6.200 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 171879024

Gaia DR2

Gaia DR2 2073547954981763328

Gaia DR3

Gaia DR3 2073547954981763328

System

Kepler-305

Percentile among Sub-Neptune cohort

Radius 2.760 R⊕ · percentile 60 / cohort 1978
Mass 6.200 M⊕ · percentile 29 / cohort 1978
Orbital period 16.74 d · percentile 56 / cohort 1946
Distance 868.48 pc · percentile 70 / cohort 1975
ESI 0.405 · percentile 53 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period
16.740 days
Semi-major axis
0.1209 AU
Eccentricity
0.000
Inclination
89.27 °

Year Length

A year here lasts approximately 16.74 Earth days (4.6% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1209 AU.

Transit Fingerprint

Depth

0.100 %

Duration

2.398 h

Impact parameter b

0.935

Rp / R★

0.030609

Transit midpoint (BJD)

2,455,192.4166

Photometric dip

Transit produces a flux drop of 997 ppm lasting ≈ 2.40 h.

Extended Orbital Architecture

Planet / star radius ratio

0.030609

Semi-major axis / stellar radius

54.490

Impact parameter (b)

0.935

Transit mid-time (BJD)

2,455,192.4166

Angular separation (arcsec)

0.13900

Eq. Temperature

576K

(303 °C)

Insolation (S⊕)

25.52

Earth = 1.00

Earth Similarity (ESI)

0.405

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

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

Rowe et al. 2014

Instrument

Kepler CCD Array

Publication

2014-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2014 at Kepler (12 shown).

Kepler-186 e · Super-Earth Kepler-395 c · Super-Earth Kepler-220 e · Super-Earth Kepler-249 d · Super-Earth Kepler-296 f · Super-Earth Kepler-367 c · Rocky Terrestrial Kepler-296 e · Super-Earth Kepler-155 c · Sub-Neptune Kepler-138 d · Super-Earth Kepler-333 c · Rocky Terrestrial Kepler-331 d · Super-Earth Kepler-267 d · Sub-Neptune

Host System: Kepler-305

Spectral Class

K-type orange

Effective Temperature

5,090 K — cooler than the Sun (5,778 K)

Estimated Age

4.37 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.792 R☉

Stellar Mass

0.827 M☉

Metallicity [Fe/H]

0.09

Extended Stellar Properties

Surface gravity (log g)

4.570 dex

Stellar density

2.326 g/cm³

Metallicity ratio

[Fe/H]

Distance
868.48 parsec
Light-years 2,832.59 ly
V-band magnitude
15.85 mag
Voyager-speed travel 49,952,719 yr

Multi-band Host Photometry — 16 bands

9.617.517.51B15.85V15.77Gaia15.81Kepler15.14TESS16.60Sloan g15.75Sloan r15.48Sloan i15.27Sloan z14.25J13.74H13.70K13.68W113.82W213.31W39.57W4

Astrometric Data

Parallax

1.124 mas

Total Proper Motion

11.427 mas/yr

PM Right Ascension

-11.12 mas/yr

PM Declination

-2.61 mas/yr

Galactic Cartesian (pc)

x = 0.372 · y = -0.665 · z = 0.647

Equatorial (J2000)

RA 299.22426° · Dec 40.34317°

Galactic ℓ, b

75.600° · 5.973°

Ecliptic λ, β

316.525° · 59.152°

HTM-20 index

-691944491

Similar Worlds

TOI-1260 c

Sub-Neptune · K-type orange

Radius 2.76 R⊕ · 240.0 ly

K2-123 b

Sub-Neptune · K-type orange

Radius 2.76 R⊕ · 526.9 ly

TOI-125 c

Sub-Neptune · K-type orange

Radius 2.76 R⊕ · 362.2 ly

TOI-969 b

Sub-Neptune · K-type orange

Radius 2.77 R⊕ · 252.0 ly

TOI-444 b

Sub-Neptune · K-type orange

Radius 2.77 R⊕ · 187.2 ly

Kepler-304 d

Sub-Neptune · K-type orange

Radius 2.75 R⊕ · 1,417.7 ly

Explore Related Categories

Sub-Neptune Planets Transit Discoveries Kepler Mission K-type orange Hosts