Confirmed Exoplanet Discovered 2021

EPIC 212297394 c

A sub-neptune orbiting the k-type orange EPIC 212297394, located approximately 1,364.6 light-years from Earth.

Key parameters at a glance

  • A radius of 2.27 Earth radii
  • A mass of 5.77 Earth masses
  • Surface gravity around 1.12 g
  • An orbital period of 5.214 days
  • Equilibrium temperature 866 K (593 °C)
  • Distance from Earth 1,364.62 light-years
  • Earth Similarity Index 0.302
  • Travel time at Voyager 1 speed 24,065,079 years
  • Almost certainly tidally locked to its host star given the close orbit

1 sibling around EPIC 212297394

EPIC 212297394 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
EPIC 212297394 b Super-Earth 1.48 2.79 2.289 1,149 2019
EPIC 212297394 c this Sub-Neptune 2.27 5.77 5.214 866 2021

EPIC 212297394 c Planet Profile

Physical Specs

Radius
2.27 R⊕
Radius (Jupiter)
0.203 R♃
Mass
5.77 M⊕
Mass (Jupiter)
0.018 M♃
Density
2.71 g/cm³
Surface Gravity
1.12 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.302
HZ Position Unknown
Controversial No

Discovery

Year 2021
Method Transit
Facility K2
Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1554of 1978

top 78.5%

This planet

2.27R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Metric Earth EPIC 212297394 c Jupiter
Radius (R⊕)1.002.2711.21
Mass (M⊕)1.005.77317.83
Density (g/cm³)5.512.711.33
Surface Gravity (g)1.001.122.53
Insolation (S⊕)1.000.037

Star Catalogue Identifiers

TIC

TIC 287331845

Gaia DR2

Gaia DR2 6294955311720593024

Gaia DR3

Gaia DR3 6294955311720593024

System

EPIC 212297394

Percentile among Sub-Neptune cohort

Radius 2.270 R⊕ · percentile 21 / cohort 1978
Mass 5.770 M⊕ · percentile 21 / cohort 1978
Orbital period 5.21 d · percentile 13 / cohort 1946
Distance 418.40 pc · percentile 42 / cohort 1975
ESI 0.302 · percentile 28 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period
5.214 days
Semi-major axis
AU
Eccentricity
Inclination
°

Year Length

A year here lasts approximately 5.21 Earth days (1.4% of a terrestrial year).

Transit Fingerprint

Depth

0.083 %

Duration

2.620 h

Impact parameter b

0.390

Rp / R★

0.025800

Transit midpoint (BJD)

2,457,222.4789

Photometric dip

Transit produces a flux drop of 828 ppm lasting ≈ 2.62 h.

Extended Orbital Architecture

Planet / star radius ratio

0.025800

Semi-major axis / stellar radius

14.450

Impact parameter (b)

0.390

Transit mid-time (BJD)

2,457,222.4789

Eq. Temperature

866K

(593 °C)

Insolation (S⊕)

Earth = 1.00

Earth Similarity (ESI)

0.302

0 = alien, 1 = Earth-identical

Insufficient insolation data — the surface is too hot to retain surface water. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

De Leon et al. 2021

Instrument

Kepler CCD Array

Publication

2021-08

Observation locale

Space

Host System: EPIC 212297394

Spectral Class

K-type orange

Effective Temperature

5,171 K — cooler than the Sun (5,778 K)

Estimated Age

Stellar Radius

0.800 R☉

Stellar Mass

0.830 M☉

Metallicity [Fe/H]

-0.03

Extended Stellar Properties

Surface gravity (log g)

4.550 dex

Stellar density

2.504 g/cm³

Metallicity ratio

[Fe/H]

Distance
418.40 parsec
Light-years 1,364.62 ly
V-band magnitude
14.61 mag
Voyager-speed travel 24,065,079 yr

Multi-band Host Photometry — 12 bands

9.315.415.38B14.61V14.19Gaia14.14Kepler13.59TESS12.74J12.22H12.19K12.12W112.17W211.97W39.25W4

Astrometric Data

Parallax

2.362 mas

Total Proper Motion

23.157 mas/yr

PM Right Ascension

-23.16 mas/yr

PM Declination

-0.24 mas/yr

Galactic Cartesian (pc)

x = -0.848 · y = -0.436 · z = -0.303

Equatorial (J2000)

RA 207.20612° · Dec -17.60990°

Galactic ℓ, b

321.819° · 43.147°

Ecliptic λ, β

211.530° · -5.983°

HTM-20 index

2078126015

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