Confirmed Exoplanet Discovered 2021

KOI-1833 d

A sub-neptune orbiting the k-type orange Kepler-968, located approximately 946.9 light-years from Earth.

Key parameters at a glance

  • A radius of 2.58 Earth radii
  • A mass of 11.02 Earth masses
  • Surface gravity around 1.66 g
  • An orbital period of 7.685 days
  • Semi-major axis 0.0634 AU
  • Equilibrium temperature 613 K (340 °C)
  • Distance from Earth 946.91 light-years
  • Earth Similarity Index 0.445
  • Travel time at Voyager 1 speed 16,698,742 years
  • Almost certainly tidally locked to its host star given the close orbit

2 siblings around Kepler-968

KOI-1833 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-968 b Sub-Neptune 2.00 4.66 3.693 745 2016
Kepler-968 c Super-Earth 1.69 3.50 5.709 644 2016
KOI-1833 d this Sub-Neptune 2.58 11.02 7.685 613 2021

KOI-1833 d Planet Profile

Physical Specs

Radius
2.58 R⊕
Radius (Jupiter)
0.230 R♃
Mass
11.02 M⊕
Mass (Jupiter)
0.035 M♃
Density
4.50 g/cm³
Surface Gravity
1.66 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.445
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

#1057of 1978

top 53.4%

This planet

2.58R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Metric Earth KOI-1833 d Jupiter
Radius (R⊕)1.002.5811.21
Mass (M⊕)1.0011.02317.83
Density (g/cm³)5.514.501.33
Surface Gravity (g)1.001.662.53
Insolation (S⊕)1.0027.350.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 11.020 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 350814607

Gaia DR2

Gaia DR2 2132152474478407040

Gaia DR3

Gaia DR3 2132152474478407040

System

Kepler-968

Percentile among Sub-Neptune cohort

Radius 2.580 R⊕ · percentile 46 / cohort 1978
Mass 11.020 M⊕ · percentile 80 / cohort 1978
Orbital period 7.69 d · percentile 25 / cohort 1946
Distance 290.32 pc · percentile 34 / cohort 1975
ESI 0.445 · percentile 61 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period
7.685 days
Semi-major axis
0.0634 AU
Eccentricity
0.000
Inclination
86.87 °

Year Length

A year here lasts approximately 7.69 Earth days (2.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0634 AU.

Transit Fingerprint

Depth

0.114 %

Duration

1.174 h

Impact parameter b

0.307

Rp / R★

0.030993

Transit midpoint (BJD)

2,454,966.3597

Photometric dip

Transit produces a flux drop of 1,141 ppm lasting ≈ 1.17 h.

Extended Orbital Architecture

Planet / star radius ratio

0.030993

Semi-major axis / stellar radius

17.430

Impact parameter (b)

0.307

Transit mid-time (BJD)

2,454,966.3597

Angular separation (arcsec)

0.21800

Eq. Temperature

613K

(340 °C)

Insolation (S⊕)

27.35

Earth = 1.00

Earth Similarity (ESI)

0.445

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

Jontof Hutter et al. 2021

Instrument

Kepler CCD Array

Publication

2021-05

Observation locale

Space

Host System: Kepler-968

Spectral Class

K-type orange

Effective Temperature

4,413 K — cooler than the Sun (5,778 K)

Estimated Age

2.14 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.667 R☉

Stellar Mass

0.681 M☉

Metallicity [Fe/H]

0.13

Extended Stellar Properties

Surface gravity (log g)

4.630 dex

Stellar density

6.117 g/cm³

Metallicity ratio

[Fe/H]

Distance
290.32 parsec
Light-years 946.91 ly
V-band magnitude
14.63 mag
Voyager-speed travel 16,698,742 yr

Multi-band Host Photometry — 16 bands

9.016.216.18B14.63V14.25Gaia14.27Kepler13.53TESS15.26Sloan g14.19Sloan r13.84Sloan i13.59Sloan z12.52J11.97H11.83K11.76W111.82W211.93W38.98W4

Astrometric Data

Parallax

3.416 mas

Total Proper Motion

5.156 mas/yr

PM Right Ascension

-4.75 mas/yr

PM Declination

2.01 mas/yr

Galactic Cartesian (pc)

x = 0.172 · y = -0.618 · z = 0.767

Equatorial (J2000)

RA 285.60259° · Dec 50.11204°

Galactic ℓ, b

80.344° · 18.818°

Ecliptic λ, β

303.407° · 71.745°

HTM-20 index

286825291

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