Key parameters at a glance

A radius of 1.80 Earth radii
A mass of 3.90 Earth masses
Surface gravity around 1.20 g
An orbital period of 12.400 days
Distance from Earth 1,281.38 light-years
Earth Similarity Index 0.824
Travel time at Voyager 1 speed 22,597,057 years

1 sibling around K2-170

K2-170 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
K2-170 b	Super-Earth	1.42	2.60	7.577	—	2018
K2-170 c this	Super-Earth	1.80	3.90	12.400	—	2018

K2-170 c Planet Profile

Physical Specs

Radius

1.80 R⊕

Radius (Jupiter)

0.161 R♃

Mass

3.90 M⊕

Mass (Jupiter)

0.012 M♃

Density

3.66 g/cm³

Surface Gravity

1.20 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.824

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

#252of 1176

top 21.3%

This planet

1.80R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-1954 b 1.80 R⊕ PSR B1257+12 d 1.80 R⊕ Kepler-11 b 1.80 R⊕

Metric	Earth	K2-170 c	Jupiter
Radius (R⊕)	1.00	1.80	11.21
Mass (M⊕)	1.00	3.90	317.83
Density (g/cm³)	5.51	3.66	1.33
Surface Gravity (g)	1.00	1.20	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 188509935

Gaia DR2

Gaia DR2 2599451994385832448

Gaia DR3

Gaia DR3 2599451994385832448

System

K2-170

Percentile among Super-Earth cohort

Radius 1.802 R⊕ · percentile 79 / cohort 1176

Mass 3.900 M⊕ · percentile 71 / cohort 1176

Orbital period 12.40 d · percentile 70 / cohort 1164

Distance 392.87 pc · percentile 39 / cohort 1171

ESI 0.824 · percentile 91 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

12.400 days

Semi-major axis

— AU

Eccentricity

—

Inclination

88.67 °

Year Length

A year here lasts approximately 12.40 Earth days (3.4% of a terrestrial year).

Transit Fingerprint

Depth

0.031 %

Duration

4.176 h

Impact parameter b

0.210

Rp / R★

0.016828

Transit midpoint (BJD)

2,456,985.6669

Photometric dip

Transit produces a flux drop of 311 ppm lasting ≈ 4.18 h.

Extended Orbital Architecture

Planet / star radius ratio

0.016828

Semi-major axis / stellar radius

20.901

Impact parameter (b)

0.210

Transit mid-time (BJD)

2,456,985.6669

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.824

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: K2-170

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,748 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.982 R☉

Stellar Mass

0.964 M☉

Metallicity [Fe/H]

-0.11

Extended Stellar Properties

Surface gravity (log g)

4.340 dex

Stellar density

1.270 g/cm³

Systemic radial velocity

-5.31 km/s

Metallicity ratio

[Fe/H]

Distance

392.87 parsec

Light-years 1,281.38 ly

V-band magnitude

12.67 mag

Voyager-speed travel 22,597,057 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

2.517 mas

Total Proper Motion

16.292 mas/yr

PM Right Ascension

-5.83 mas/yr

PM Declination

-15.21 mas/yr

Galactic Cartesian (pc)

x = 0.880 · y = -0.402 · z = -0.252

Equatorial (J2000)

RA 335.45069° · Dec -14.59336°

Galactic ℓ, b

45.054° · -53.036°

Ecliptic λ, β

331.942° · -4.085°

HTM-20 index

494173039