Key parameters at a glance

A radius of 2.90 Earth radii
A mass of 8.75 Earth masses
Surface gravity around 1.04 g
An orbital period of 56.675 days
Semi-major axis 0.2836 AU
Equilibrium temperature 522 K (249 °C)
Distance from Earth 2,903.75 light-years
Earth Similarity Index 0.451
Travel time at Voyager 1 speed 51,207,696 years

Kepler-1447 b Planet Profile

Physical Specs

Radius

2.90 R⊕

Radius (Jupiter)

0.259 R♃

Mass

8.75 M⊕

Mass (Jupiter)

0.028 M♃

Density

1.97 g/cm³

Surface Gravity

1.04 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.451

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#621of 1978

top 31.3%

This planet

2.90R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-130 c 2.90 R⊕ Kepler-276 c 2.90 R⊕ Kepler-314 c 2.90 R⊕

Metric	Earth	Kepler-1447 b	Jupiter
Radius (R⊕)	1.00	2.90	11.21
Mass (M⊕)	1.00	8.75	317.83
Density (g/cm³)	5.51	1.97	1.33
Surface Gravity (g)	1.00	1.04	2.53
Insolation (S⊕)	1.00	10.35	0.037

Star Catalogue Identifiers

TIC

TIC 416281317

Gaia DR2

Gaia DR2 2133132276778226176

Gaia DR3

Gaia DR3 2133132276778226176

System

Kepler-1447

Percentile among Sub-Neptune cohort

Radius 2.900 R⊕ · percentile 68 / cohort 1978

Mass 8.750 M⊕ · percentile 62 / cohort 1978

Orbital period 56.67 d · percentile 88 / cohort 1946

Distance 890.30 pc · percentile 72 / cohort 1975

ESI 0.451 · percentile 62 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

56.675 days

Semi-major axis

0.2836 AU

Eccentricity

0.000

Inclination

89.44 °

Year Length

A year here lasts approximately 56.67 Earth days (15.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2836 AU.

Transit Fingerprint

Depth

0.088 %

Duration

5.422 h

Impact parameter b

0.180

Rp / R★

0.027673

Transit midpoint (BJD)

2,454,993.4501

Photometric dip

Transit produces a flux drop of 883 ppm lasting ≈ 5.42 h.

Extended Orbital Architecture

Planet / star radius ratio

0.027673

Semi-major axis / stellar radius

80.790

Impact parameter (b)

0.180

Transit mid-time (BJD)

2,454,993.4501

Angular separation (arcsec)

0.31900

Eq. Temperature

522K

(249 °C)

Insolation (S⊕)

10.35

Earth = 1.00

Earth Similarity (ESI)

0.451

0 = alien, 1 = Earth-identical

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

Discovery Paper

Primary reference

Morton et al. 2016

Instrument

Kepler CCD Array

Publication

2016-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2016 at Kepler (12 shown).

Kepler-1512 b · Rocky Terrestrial Kepler-1410 b · Super-Earth Kepler-560 b · Super-Earth Kepler-1389 b · Super-Earth Kepler-1450 b · Super-Earth Kepler-1544 b · Super-Earth Kepler-1459 b · Super-Earth Kepler-1638 b · Super-Earth Kepler-737 b · Super-Earth Kepler-1185 b · Super-Earth Kepler-1178 b · Rocky Terrestrial Kepler-1040 b · Sub-Neptune

Host System: Kepler-1447

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,722 K — cooler than the Sun (5,778 K)

Estimated Age

4.17 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.950 R☉

Stellar Mass

0.970 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.470 dex

Stellar density

3.105 g/cm³

Metallicity ratio

[Fe/H]

Distance

890.30 parsec

Light-years 2,903.75 ly

V-band magnitude

14.75 mag

Voyager-speed travel 51,207,696 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.095 mas

Total Proper Motion

14.424 mas/yr

PM Right Ascension

-4.55 mas/yr

PM Declination

-13.69 mas/yr

Galactic Cartesian (pc)

x = 0.213 · y = -0.596 · z = 0.774

Equatorial (J2000)

RA 289.64343° · Dec 50.72702°

Galactic ℓ, b

81.931° · 16.645°

Ecliptic λ, β

311.671° · 71.335°

HTM-20 index

115422041