Key parameters at a glance

A radius of 4.34 Earth radii
A mass of 17.40 Earth masses
Surface gravity around 0.92 g
An orbital period of 11.893 days
Semi-major axis 0.0959 AU
Equilibrium temperature 923 K (650 °C)
Distance from Earth 1,487.48 light-years
Earth Similarity Index 0.217
Travel time at Voyager 1 speed 26,231,710 years

K2-245 b Planet Profile

Physical Specs

Radius

4.34 R⊕

Radius (Jupiter)

0.387 R♃

Mass

17.40 M⊕

Mass (Jupiter)

0.055 M♃

Density

1.17 g/cm³

Surface Gravity

0.92 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.217

HZ Position Inner

Controversial No

Discovery

Year 2018

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#484of 574

top 84.1%

This planet

4.34R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

HD 21693 c 4.34 R⊕ TOI-470 b 4.34 R⊕ Kepler-413 b 4.35 R⊕

Metric	Earth	K2-245 b	Jupiter
Radius (R⊕)	1.00	4.34	11.21
Mass (M⊕)	1.00	17.40	317.83
Density (g/cm³)	5.51	1.17	1.33
Surface Gravity (g)	1.00	0.92	2.53
Insolation (S⊕)	1.00	83.00	0.037

Star Catalogue Identifiers

TIC

TIC 147677253

Gaia DR2

Gaia DR2 3694743765254445312

Gaia DR3

Gaia DR3 3694743765254445312

System

K2-245

Percentile among Neptune-like cohort

Radius 4.340 R⊕ · percentile 15 / cohort 574

Mass 17.400 M⊕ · percentile 20 / cohort 574

Orbital period 11.89 d · percentile 40 / cohort 524

Distance 456.06 pc · percentile 55 / cohort 572

ESI 0.217 · percentile 31 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

11.893 days

Semi-major axis

0.0959 AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 11.89 Earth days (3.3% of a terrestrial year) at a mean orbital distance of 0.0959 AU.

Transit Fingerprint

Depth

0.107 %

Duration

4.200 h

Impact parameter b

0.380

Rp / R★

0.031700

Transit midpoint (BJD)

2,457,587.5524

Photometric dip

Transit produces a flux drop of 1,070 ppm lasting ≈ 4.20 h.

Extended Orbital Architecture

Planet / star radius ratio

0.031700

Semi-major axis / stellar radius

17.500

Impact parameter (b)

0.380

Transit mid-time (BJD)

2,457,587.5524

Angular separation (arcsec)

0.21000

Eq. Temperature

923K

(650 °C)

Insolation (S⊕)

83.00

Earth = 1.00

Earth Similarity (ESI)

0.217

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

Livingston et al. 2018

Instrument

Kepler CCD Array

Publication

2018-08

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: K2-245

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,793 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.250 R☉

Stellar Mass

0.830 M☉

Metallicity [Fe/H]

-0.45

Extended Stellar Properties

Surface gravity (log g)

4.160 dex

Stellar density

1.019 g/cm³

Systemic radial velocity

29.75 km/s

Rotational v·sin i

4.62 km/s

Activity index (log R'HK)

-5.148

Metallicity ratio

[Fe/H]

Distance

456.06 parsec

Light-years 1,487.48 ly

V-band magnitude

12.76 mag

Voyager-speed travel 26,231,710 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

2.164 mas

Total Proper Motion

25.985 mas/yr

PM Right Ascension

-25.76 mas/yr

PM Declination

-3.42 mas/yr

Galactic Cartesian (pc)

x = -0.996 · y = -0.090 · z = -0.028

Equatorial (J2000)

RA 185.18156° · Dec -1.59091°

Galactic ℓ, b

287.273° · 60.344°

Ecliptic λ, β

185.383° · 0.598°

HTM-20 index

2010672141