Key parameters at a glance

A radius of 1.61 Earth radii
A mass of 3.22 Earth masses
Surface gravity around 1.24 g
An orbital period of 5.869 days
Distance from Earth 745.73 light-years
Earth Similarity Index 0.866
Travel time at Voyager 1 speed 13,150,883 years

K2-173 b Planet Profile

Physical Specs

Radius

1.61 R⊕

Radius (Jupiter)

0.143 R♃

Mass

3.22 M⊕

Mass (Jupiter)

0.010 M♃

Density

4.25 g/cm³

Surface Gravity

1.24 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.866

HZ Position Unknown

Controversial No

Discovery

Year 2018

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#565of 1176

top 48.0%

This planet

1.61R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-62 e 1.61 R⊕ Kepler-140 b 1.61 R⊕ Kepler-149 c 1.61 R⊕

Metric	Earth	K2-173 b	Jupiter
Radius (R⊕)	1.00	1.61	11.21
Mass (M⊕)	1.00	3.22	317.83
Density (g/cm³)	5.51	4.25	1.33
Surface Gravity (g)	1.00	1.24	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 242993844

Gaia DR2

Gaia DR2 39404267653786624

Gaia DR3

Gaia DR3 39404267653786624

System

K2-173

Percentile among Super-Earth cohort

Radius 1.608 R⊕ · percentile 52 / cohort 1176

Mass 3.220 M⊕ · percentile 47 / cohort 1176

Orbital period 5.87 d · percentile 46 / cohort 1164

Distance 228.64 pc · percentile 26 / cohort 1171

ESI 0.866 · percentile 95 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

5.869 days

Semi-major axis

— AU

Eccentricity

—

Inclination

87.83 °

Year Length

A year here lasts approximately 5.87 Earth days (1.6% of a terrestrial year).

Transit Fingerprint

Depth

0.020 %

Duration

2.825 h

Rp / R★

0.017487

Transit midpoint (BJD)

2,457,067.1411

Photometric dip

Transit produces a flux drop of 200 ppm lasting ≈ 2.83 h.

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.866

0 = alien, 1 = Earth-identical

Discovery Paper

Primary reference

Mayo et al. 2018

Instrument

Kepler CCD Array

Publication

2018-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2018 at K2 (12 shown).

K2-190 c · Rocky Terrestrial K2-183 b · Rocky Terrestrial K2-209 b · Rocky Terrestrial K2-210 b · Rocky Terrestrial K2-165 b · Super-Earth K2-169 b · Super-Earth K2-148 b · Super-Earth K2-219 b · Super-Earth K2-190 b · Super-Earth K2-200 b · Super-Earth K2-201 b · Super-Earth K2-170 b · Super-Earth

Host System: K2-173

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,580 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.843 R☉

Stellar Mass

0.882 M☉

Metallicity [Fe/H]

-0.25

Extended Stellar Properties

Surface gravity (log g)

4.520 dex

Stellar density

1.381 g/cm³

Systemic radial velocity

102.96 km/s

Metallicity ratio

[Fe/H]

Distance

228.64 parsec

Light-years 745.73 ly

V-band magnitude

12.52 mag

Voyager-speed travel 13,150,883 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

4.345 mas

Total Proper Motion

67.745 mas/yr

PM Right Ascension

64.89 mas/yr

PM Declination

19.47 mas/yr

Galactic Cartesian (pc)

x = 0.476 · y = 0.837 · z = 0.269

Equatorial (J2000)

RA 60.37524° · Dec 15.62513°

Galactic ℓ, b

175.875° · -27.133°

Ecliptic λ, β

61.453° · -4.927°

HTM-20 index

-710169208