Key parameters at a glance

A radius of 0.95 Earth radii
A mass of 0.81 Earth masses
Surface gravity around 0.90 g
An orbital period of 3.144 days
Equilibrium temperature 460 K (187 °C)
Distance from Earth 185.81 light-years
Earth Similarity Index 0.681
Travel time at Voyager 1 speed 3,276,698 years
Almost certainly tidally locked to its host star given the close orbit

Context from the literature

K2-315b is an exoplanet located 185.3 light years away from Earth in the southern zodiac constellation Libra. It orbits the red dwarf K2-315.

Excerpted from Wikipedia · full article

K2-315 b Planet Profile

Physical Specs

Radius

0.95 R⊕

Radius (Jupiter)

0.085 R♃

Mass

0.81 M⊕

Mass (Jupiter)

0.003 M♃

Density

5.18 g/cm³

Surface Gravity

0.90 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.681

HZ Position Inner

Controversial No

Discovery

Year 2020

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#376of 570

top 65.8%

This planet

0.95R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-1049 b 0.95 R⊕ Kepler-106 d 0.95 R⊕ Kepler-271 c 0.95 R⊕

Metric	Earth	K2-315 b	Jupiter
Radius (R⊕)	1.00	0.95	11.21
Mass (M⊕)	1.00	0.81	317.83
Density (g/cm³)	5.51	5.18	1.33
Surface Gravity (g)	1.00	0.90	2.53
Insolation (S⊕)	1.00	7.45	0.037

Star Catalogue Identifiers

TIC

TIC 70298662

Gaia DR2

Gaia DR2 6255978483510095488

Gaia DR3

Gaia DR3 6255978483510095488

System

K2-315

Percentile among Rocky Terrestrial cohort

Radius 0.950 R⊕ · percentile 33 / cohort 570

Mass 0.809 M⊕ · percentile 29 / cohort 570

Orbital period 3.14 d · percentile 35 / cohort 567

Distance 56.97 pc · percentile 18 / cohort 566

ESI 0.681 · percentile 82 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

3.144 days

Semi-major axis

— AU

Eccentricity

—

Inclination

88.74 °

Year Length

A year here lasts approximately 3.14 Earth days (0.9% of a terrestrial year).

Transit Fingerprint

Duration

0.821 h

Impact parameter b

0.565

Rp / R★

0.044400

Transit midpoint (BJD)

2,457,990.8620

Extended Orbital Architecture

Planet / star radius ratio

0.044400

Semi-major axis / stellar radius

25.720

Impact parameter (b)

0.565

Transit mid-time (BJD)

2,457,990.8620

Eq. Temperature

460K

(187 °C)

Insolation (S⊕)

7.45

Earth = 1.00

Earth Similarity (ESI)

0.681

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Niraula et al. 2020

Instrument

Kepler CCD Array

Publication

2020-10

Observation locale

Space

Discovery cohort

Planets confirmed in 2020 at K2 (12 shown).

EPIC 201170410.02 · Rocky Terrestrial EPIC 201757695.02 · Rocky Terrestrial K2-323 b · Sub-Neptune K2-316 c · Super-Earth K2-318 b · Super-Earth K2-325 b · Sub-Neptune K2-317 b · Sub-Neptune K2-322 b · Super-Earth K2-319 b · Sub-Neptune K2-316 b · Super-Earth K2-324 b · Sub-Neptune K2-320 b · Sub-Neptune

Host System: K2-315

Spectral Class

M-type red dwarf

Effective Temperature

3,300 K — cooler than the Sun (5,778 K)

Estimated Age

1.00 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.196 R☉

Stellar Mass

0.174 M☉

Metallicity [Fe/H]

-0.24

Extended Stellar Properties

Surface gravity (log g)

5.094 dex

Stellar density

32.600 g/cm³

Systemic radial velocity

6.25 km/s

Rotational v·sin i

5.00 km/s

Metallicity ratio

[Fe/H]

Distance

56.97 parsec

Light-years 185.81 ly

V-band magnitude

17.67 mag

Voyager-speed travel 3,276,698 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

17.525 mas

Total Proper Motion

141.546 mas/yr

PM Right Ascension

-120.26 mas/yr

PM Declination

74.66 mas/yr

Galactic Cartesian (pc)

x = -0.628 · y = -0.698 · z = -0.344

Equatorial (J2000)

RA 228.02109° · Dec -20.10816°

Galactic ℓ, b

342.432° · 31.768°

Ecliptic λ, β

231.054° · -2.163°

HTM-20 index

2007633675

Wikipedia → Image: Wikimedia Commons · Martin Vargic / Halcyon Maps · CC BY 3.0