Confirmed Exoplanet Discovered 2021

Kepler-1311 d

A neptune-like orbiting the g-type yellow (sun-like) Kepler-1311, located approximately 2,825.6 light-years from Earth.

Key parameters at a glance

  • A radius of 9.66 Earth radii
  • A mass of 67.50 Earth masses
  • Surface gravity around 0.72 g
  • An orbital period of 197.511 days
  • Semi-major axis 0.6843 AU
  • Equilibrium temperature 391 K (118 °C)
  • Distance from Earth 2,825.59 light-years
  • Earth Similarity Index 0.333
  • Travel time at Voyager 1 speed 49,829,286 years

2 siblings around Kepler-1311

Kepler-1311 d shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet Type Radius (R⊕) Mass (M⊕) Period (d) Eq. T (K) Year
Kepler-1311 c Rocky Terrestrial 1.22 1.98 2.536 1,671 2016
Kepler-1311 b Rocky Terrestrial 1.24 2.07 11.173 1,019 2016
Kepler-1311 d this Neptune-like 9.66 67.50 197.511 391 2021

Kepler-1311 d Planet Profile

Physical Specs

Radius
9.66 R⊕
Radius (Jupiter)
0.862 R♃
Mass
67.50 M⊕
Mass (Jupiter)
0.212 M♃
Density
0.41 g/cm³
Surface Gravity
0.72 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.333
HZ Position Inner
Controversial No

Discovery

Year 2021
Method Transit
Facility Kepler
Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#27of 574

top 4.5%

This planet

9.66R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Metric Earth Kepler-1311 d Jupiter
Radius (R⊕)1.009.6611.21
Mass (M⊕)1.0067.50317.83
Density (g/cm³)5.510.411.33
Surface Gravity (g)1.000.722.53
Insolation (S⊕)1.006.000.037

Star Catalogue Identifiers

TIC

TIC 159106207

Gaia DR2

Gaia DR2 2102877015319104640

Gaia DR3

Gaia DR3 2102877015319104640

System

Kepler-1311

Percentile among Neptune-like cohort

Radius 9.658 R⊕ · percentile 95 / cohort 574
Mass 67.500 M⊕ · percentile 84 / cohort 574
Orbital period 197.51 d · percentile 89 / cohort 524
Distance 866.33 pc · percentile 70 / cohort 572
ESI 0.333 · percentile 59 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period
197.511 days
Semi-major axis
0.6843 AU
Eccentricity
0.000
Inclination
89.49 °

Year Length

A year here lasts approximately 197.51 Earth days (54.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.6843 AU.

Transit Fingerprint

Depth

0.258 %

Duration

11.245 h

Impact parameter b

0.834

Rp / R★

0.053468

Transit midpoint (BJD)

2,455,105.3860

Photometric dip

Transit produces a flux drop of 2,576 ppm lasting ≈ 11.24 h.

Extended Orbital Architecture

Planet / star radius ratio

0.053468

Semi-major axis / stellar radius

90.200

Impact parameter (b)

0.834

Transit mid-time (BJD)

2,455,105.3860

Angular separation (arcsec)

0.79000

Eq. Temperature

391K

(118 °C)

Insolation (S⊕)

6.00

Earth = 1.00

Earth Similarity (ESI)

0.333

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

Valizadegan et al. 2022

Instrument

Kepler CCD Array

Publication

2022-02

Observation locale

Space

Host System: Kepler-1311

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,616 K — cooler than the Sun (5,778 K)

Estimated Age

7.59 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.674 R☉

Stellar Mass

1.032 M☉

Metallicity [Fe/H]

0.04

Extended Stellar Properties

Surface gravity (log g)

4.004 dex

Stellar density

0.361 g/cm³

Metallicity ratio

[Fe/H]

Distance
866.33 parsec
Light-years 2,825.59 ly
V-band magnitude
13.53 mag
Voyager-speed travel 49,829,286 yr

Multi-band Host Photometry — 16 bands

9.314.214.24B13.53V13.32Gaia13.35Kepler12.86TESS13.79Sloan g13.28Sloan r13.16Sloan i13.07Sloan z12.17J11.86H11.83K11.81W111.84W211.89W39.30W4

Astrometric Data

Parallax

1.126 mas

Total Proper Motion

7.026 mas/yr

PM Right Ascension

3.20 mas/yr

PM Declination

6.26 mas/yr

Galactic Cartesian (pc)

x = 0.243 · y = -0.679 · z = 0.692

Equatorial (J2000)

RA 289.65126° · Dec 43.82444°

Galactic ℓ, b

75.376° · 13.875°

Ecliptic λ, β

304.885° · 64.901°

HTM-20 index

931493814

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