Confirmed Exoplanet Discovered 2018

K2-287 b

A neptune-like orbiting the g-type yellow (sun-like) K2-287, located approximately 516.4 light-years from Earth.

Key parameters at a glance

  • A radius of 9.49 Earth radii
  • A mass of 100.12 Earth masses
  • Surface gravity around 1.11 g
  • An orbital period of 14.893 days
  • Semi-major axis 0.1206 AU
  • Equilibrium temperature 804 K (531 °C)
  • Distance from Earth 516.42 light-years
  • Earth Similarity Index 0.186
  • Travel time at Voyager 1 speed 9,107,050 years

K2-287 b Planet Profile

Physical Specs

Radius
9.49 R⊕
Radius (Jupiter)
0.847 R♃
Mass
100.12 M⊕
Mass (Jupiter)
0.315 M♃
Density
0.63 g/cm³
Surface Gravity
1.11 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.186
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

#46of 574

top 7.8%

This planet

9.49R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Metric Earth K2-287 b Jupiter
Radius (R⊕)1.009.4911.21
Mass (M⊕)1.00100.12317.83
Density (g/cm³)5.510.631.33
Surface Gravity (g)1.001.112.53
Insolation (S⊕)1.000.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 100.116 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 73848324

Gaia DR2

Gaia DR2 6239702034929248512

Gaia DR3

Gaia DR3 6239702034929248512

System

K2-287

Percentile among Neptune-like cohort

Radius 9.494 R⊕ · percentile 92 / cohort 574
Mass 100.116 M⊕ · percentile 91 / cohort 574
Orbital period 14.89 d · percentile 45 / cohort 524
Distance 158.34 pc · percentile 34 / cohort 572
ESI 0.186 · percentile 24 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period
14.893 days
Semi-major axis
0.1206 AU
Eccentricity
0.478
Inclination
88.13 °

Year Length

A year here lasts approximately 14.89 Earth days (4.1% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.1206 AU.

Transit Fingerprint

Depth

0.640 %

Duration

3.500 h

Impact parameter b

0.800

Rp / R★

0.080140

Transit midpoint (BJD)

2,458,001.7214

Photometric dip

Transit produces a flux drop of 6,400 ppm lasting ≈ 3.50 h.

Extended Orbital Architecture

Planet / star radius ratio

0.080140

Semi-major axis / stellar radius

23.870

Impact parameter (b)

0.800

RV semi-amplitude (K)

28.800 m/s

Transit mid-time (BJD)

2,458,001.7214

Long. of periastron (ω)

10.10°

Sky-projected obliquity (λ)

23.00°

Angular separation (arcsec)

0.76200

Eq. Temperature

804K

(531 °C)

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.186

0 = alien, 1 = Earth-identical

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

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Jord Aacute N et al. 2019

Instrument

Kepler CCD Array

Publication

2019-03

Observation locale

Space

Host System: K2-287

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,695 K — cooler than the Sun (5,778 K)

Estimated Age

4.50 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.070 R☉

Stellar Mass

1.056 M☉

Metallicity [Fe/H]

0.20

Extended Stellar Properties

Surface gravity (log g)

4.398 dex

Stellar density

1.217 g/cm³

Systemic radial velocity

32.93 km/s

Rotational v·sin i

3.20 km/s

Metallicity ratio

[Fe/H]

Distance
158.34 parsec
Light-years 516.42 ly
V-band magnitude
11.41 mag
Voyager-speed travel 9,107,050 yr

Multi-band Host Photometry — 12 bands

8.212.012.01B11.41V11.07Gaia11.06Kepler10.48TESS9.68J9.28H9.19K9.11W19.15W29.09W38.15W4

Astrometric Data

Parallax

6.288 mas

Total Proper Motion

18.479 mas/yr

PM Right Ascension

-4.59 mas/yr

PM Declination

-17.90 mas/yr

Galactic Cartesian (pc)

x = -0.556 · y = -0.739 · z = -0.380

Equatorial (J2000)

RA 233.07434° · Dec -22.35834°

Galactic ℓ, b

345.043° · 27.070°

Ecliptic λ, β

236.185° · -3.149°

HTM-20 index

1875203132

Similar Worlds

Explore Related Categories