Key parameters at a glance

A radius of 2.43 Earth radii
A mass of 6.48 Earth masses
Surface gravity around 1.10 g
An orbital period of 8.006 days
Semi-major axis 0.0740 AU
Equilibrium temperature 956 K (683 °C)
Distance from Earth 2,717.42 light-years
Earth Similarity Index 0.265
Travel time at Voyager 1 speed 47,921,657 years

1 sibling around Kepler-173

Kepler-173 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-173 b	Super-Earth	1.29	2.21	4.264	1,179	2014
Kepler-173 c this	Sub-Neptune	2.43	6.48	8.006	956	2014

Kepler-173 c Planet Profile

Physical Specs

Radius

2.43 R⊕

Radius (Jupiter)

0.217 R♃

Mass

6.48 M⊕

Mass (Jupiter)

0.020 M♃

Density

2.48 g/cm³

Surface Gravity

1.10 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.265

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

#1281of 1978

top 64.7%

This planet

2.43R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-233 b 2.43 R⊕ Kepler-55 b 2.43 R⊕ TOI-4184 b 2.43 R⊕

Metric	Earth	Kepler-173 c	Jupiter
Radius (R⊕)	1.00	2.43	11.21
Mass (M⊕)	1.00	6.48	317.83
Density (g/cm³)	5.51	2.48	1.33
Surface Gravity (g)	1.00	1.10	2.53
Insolation (S⊕)	1.00	258.42	0.037

Star Catalogue Identifiers

TIC

TIC 378160351

Gaia DR2

Gaia DR2 2077485271747441280

Gaia DR3

Gaia DR3 2077485271747441280

System

Kepler-173

Percentile among Sub-Neptune cohort

Radius 2.430 R⊕ · percentile 35 / cohort 1978

Mass 6.480 M⊕ · percentile 33 / cohort 1978

Orbital period 8.01 d · percentile 26 / cohort 1946

Distance 833.17 pc · percentile 68 / cohort 1975

ESI 0.265 · percentile 20 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

8.006 days

Semi-major axis

0.0740 AU

Eccentricity

0.000

Inclination

89.74 °

Year Length

A year here lasts approximately 8.01 Earth days (2.2% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0740 AU.

Transit Fingerprint

Depth

0.066 %

Duration

3.129 h

Impact parameter b

0.370

Rp / R★

0.023607

Transit midpoint (BJD)

2,455,003.5034

Photometric dip

Transit produces a flux drop of 658 ppm lasting ≈ 3.13 h.

Extended Orbital Architecture

Planet / star radius ratio

0.023607

Semi-major axis / stellar radius

20.020

Impact parameter (b)

0.370

Transit mid-time (BJD)

2,455,003.5034

Angular separation (arcsec)

0.08880

Eq. Temperature

956K

(683 °C)

Insolation (S⊕)

258.42

Earth = 1.00

Earth Similarity (ESI)

0.265

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

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-173

Spectral Class

F-type yellow-white

Effective Temperature

6,031 K — hotter than the Sun (5,778 K)

Estimated Age

3.30 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.949 R☉

Stellar Mass

1.067 M☉

Metallicity [Fe/H]

0.04

Extended Stellar Properties

Surface gravity (log g)

4.404 dex

Stellar density

0.860 g/cm³

Metallicity ratio

[M/H]

Distance

833.17 parsec

Light-years 2,717.42 ly

V-band magnitude

14.36 mag

Voyager-speed travel 47,921,657 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.172 mas

Total Proper Motion

9.068 mas/yr

PM Right Ascension

-4.13 mas/yr

PM Declination

-8.07 mas/yr

Galactic Cartesian (pc)

x = 0.310 · y = -0.677 · z = 0.668

Equatorial (J2000)

RA 294.64662° · Dec 41.88410°

Galactic ℓ, b

75.248° · 9.734°

Ecliptic λ, β

311.147° · 61.848°

HTM-20 index

-1036932597