Key parameters at a glance

A radius of 2.56 Earth radii
A mass of 7.08 Earth masses
Surface gravity around 1.08 g
An orbital period of 8.358 days
Semi-major axis 0.0806 AU
Equilibrium temperature 848 K (575 °C)
Distance from Earth 807.68 light-years
Earth Similarity Index 0.295
Travel time at Voyager 1 speed 14,243,488 years

K2-197 b Planet Profile

Physical Specs

Radius

2.56 R⊕

Radius (Jupiter)

0.228 R♃

Mass

7.08 M⊕

Mass (Jupiter)

0.022 M♃

Density

2.32 g/cm³

Surface Gravity

1.08 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.295

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

#1092of 1978

top 55.2%

This planet

2.56R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-171 c 2.56 R⊕ Kepler-640 b 2.56 R⊕ Kepler-175 b 2.56 R⊕

Metric	Earth	K2-197 b	Jupiter
Radius (R⊕)	1.00	2.56	11.21
Mass (M⊕)	1.00	7.08	317.83
Density (g/cm³)	5.51	2.32	1.33
Surface Gravity (g)	1.00	1.08	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 179032688

Gaia DR2

Gaia DR2 3630460126445437440

Gaia DR3

Gaia DR3 3630460126445437440

System

K2-197

Percentile among Sub-Neptune cohort

Radius 2.560 R⊕ · percentile 44 / cohort 1978

Mass 7.080 M⊕ · percentile 41 / cohort 1978

Orbital period 8.36 d · percentile 28 / cohort 1946

Distance 247.64 pc · percentile 32 / cohort 1975

ESI 0.295 · percentile 26 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

8.358 days

Semi-major axis

0.0806 AU

Eccentricity

—

Inclination

88.51 °

Year Length

A year here lasts approximately 8.36 Earth days (2.3% of a terrestrial year) at a mean orbital distance of 0.0806 AU.

Transit Fingerprint

Depth

0.055 %

Duration

3.470 h

Impact parameter b

0.450

Rp / R★

0.025300

Transit midpoint (BJD)

2,457,218.1825

Photometric dip

Transit produces a flux drop of 550 ppm lasting ≈ 3.47 h.

Extended Orbital Architecture

Planet / star radius ratio

0.025300

Semi-major axis / stellar radius

16.290

Impact parameter (b)

0.450

Transit mid-time (BJD)

2,457,218.1825

Angular separation (arcsec)

0.32500

Eq. Temperature

848K

(575 °C)

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.295

0 = alien, 1 = Earth-identical

Insufficient insolation data — the surface is too hot to retain surface water.

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: K2-197

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,667 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.930 R☉

Stellar Mass

1.000 M☉

Metallicity [Fe/H]

0.08

Extended Stellar Properties

Surface gravity (log g)

4.500 dex

Stellar density

1.160 g/cm³

Systemic radial velocity

-7.88 km/s

Metallicity ratio

[Fe/H]

Distance

247.64 parsec

Light-years 807.68 ly

V-band magnitude

12.20 mag

Voyager-speed travel 14,243,488 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

4.010 mas

Total Proper Motion

46.881 mas/yr

PM Right Ascension

-46.76 mas/yr

PM Declination

3.31 mas/yr

Galactic Cartesian (pc)

x = -0.917 · y = -0.378 · z = -0.128

Equatorial (J2000)

RA 202.39348° · Dec -7.37398°

Galactic ℓ, b

319.274° · 54.283°

Ecliptic λ, β

203.443° · 1.864°

HTM-20 index

1156950526