Confirmed Exoplanet Discovered 2017

K2-119 b

A sub-neptune orbiting the k-type orange K2-119, located approximately 1,192.4 light-years from Earth.

Key parameters at a glance

  • A radius of 2.53 Earth radii
  • A mass of 6.94 Earth masses
  • Surface gravity around 1.08 g
  • An orbital period of 7.727 days
  • Semi-major axis 0.0698 AU
  • Equilibrium temperature 666 K (393 °C)
  • Distance from Earth 1,192.36 light-years
  • Earth Similarity Index 0.378
  • Travel time at Voyager 1 speed 21,027,344 years
  • Almost certainly tidally locked to its host star given the close orbit

K2-119 b Planet Profile

Physical Specs

Radius
2.53 R⊕
Radius (Jupiter)
0.226 R♃
Mass
6.94 M⊕
Mass (Jupiter)
0.022 M♃
Density
2.35 g/cm³
Surface Gravity
1.08 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.378
HZ Position Inner
Controversial No

Discovery

Year 2017
Method Transit
Facility K2
Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1133of 1978

top 57.2%

This planet

2.53R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Metric Earth K2-119 b Jupiter
Radius (R⊕)1.002.5311.21
Mass (M⊕)1.006.94317.83
Density (g/cm³)5.512.351.33
Surface Gravity (g)1.001.082.53
Insolation (S⊕)1.0054.900.037

Star Catalogue Identifiers

TIC

TIC 293460551

Gaia DR2

Gaia DR2 658274970145911424

Gaia DR3

Gaia DR3 658274970145911424

System

K2-119

Percentile among Sub-Neptune cohort

Radius 2.530 R⊕ · percentile 42 / cohort 1978
Mass 6.940 M⊕ · percentile 39 / cohort 1978
Orbital period 7.73 d · percentile 25 / cohort 1946
Distance 365.58 pc · percentile 39 / cohort 1975
ESI 0.378 · percentile 48 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period
7.727 days
Semi-major axis
0.0698 AU
Eccentricity
0.070
Inclination
89.40 °

Year Length

A year here lasts approximately 7.73 Earth days (2.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0698 AU.

Transit Fingerprint

Depth

0.123 %

Duration

2.904 h

Impact parameter b

0.410

Rp / R★

0.032800

Transit midpoint (BJD)

2,457,148.8311

Photometric dip

Transit produces a flux drop of 1,233 ppm lasting ≈ 2.90 h.

Extended Orbital Architecture

Planet / star radius ratio

0.032800

Semi-major axis / stellar radius

19.230

Impact parameter (b)

0.410

Transit mid-time (BJD)

2,457,148.8311

Long. of periastron (ω)

-37.71°

Angular separation (arcsec)

0.19100

Eq. Temperature

666K

(393 °C)

Insolation (S⊕)

54.90

Earth = 1.00

Earth Similarity (ESI)

0.378

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

Dressing et al. 2017

Instrument

Kepler CCD Array

Publication

2017-11

Observation locale

Space

Host System: K2-119

Spectral Class

K-type orange

Effective Temperature

4,740 K — cooler than the Sun (5,778 K)

Estimated Age

Stellar Radius

0.710 R☉

Stellar Mass

0.760 M☉

Metallicity [Fe/H]

-0.05

Extended Stellar Properties

Surface gravity (log g)

4.620 dex

Stellar density

2.251 g/cm³

Metallicity ratio

[Fe/H]

Distance
365.58 parsec
Light-years 1,192.36 ly
V-band magnitude
14.82 mag
Voyager-speed travel 21,027,344 yr

Multi-band Host Photometry — 17 bands

8.817.917.88U15.97B14.82V14.51Gaia14.49Kepler13.82TESS15.49Sloan g14.44Sloan r14.85Sloan i13.93Sloan z12.84J12.27H12.17K12.12W112.17W212.18W38.79W4

Astrometric Data

Parallax

2.707 mas

Total Proper Motion

37.488 mas/yr

PM Right Ascension

30.03 mas/yr

PM Declination

-22.44 mas/yr

Galactic Cartesian (pc)

x = -0.640 · y = 0.711 · z = 0.291

Equatorial (J2000)

RA 132.00987° · Dec 16.90177°

Galactic ℓ, b

209.765° · 33.186°

Ecliptic λ, β

129.820° · -0.920°

HTM-20 index

-1683586377

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