Confirmed Exoplanet Discovered 2021

Kepler-1802 c

A sub-neptune orbiting the k-type orange Kepler-1802, located approximately 2,076.6 light-years from Earth.

Key parameters at a glance

  • A radius of 2.32 Earth radii
  • A mass of 6.00 Earth masses
  • Surface gravity around 1.11 g
  • An orbital period of 33.136 days
  • Semi-major axis 0.1748 AU
  • Equilibrium temperature 357 K (84 °C)
  • Distance from Earth 2,076.62 light-years
  • Earth Similarity Index 0.675
  • Travel time at Voyager 1 speed 36,621,116 years
  • Almost certainly tidally locked to its host star given the close orbit

1 sibling around Kepler-1802

Kepler-1802 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
Kepler-1802 b Super-Earth 1.67 3.43 15.450 581 2021
Kepler-1802 c this Sub-Neptune 2.32 6.00 33.136 357 2021

Kepler-1802 c Planet Profile

Physical Specs

Radius
2.32 R⊕
Radius (Jupiter)
0.207 R♃
Mass
6.00 M⊕
Mass (Jupiter)
0.019 M♃
Density
2.63 g/cm³
Surface Gravity
1.11 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.675
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

#1467of 1978

top 74.1%

This planet

2.32R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Metric Earth Kepler-1802 c Jupiter
Radius (R⊕)1.002.3211.21
Mass (M⊕)1.006.00317.83
Density (g/cm³)5.512.631.33
Surface Gravity (g)1.001.112.53
Insolation (S⊕)1.003.860.037

Star Catalogue Identifiers

TIC

TIC 239291510

Gaia DR2

Gaia DR2 2076053604520641024

Gaia DR3

Gaia DR3 2076053604520641024

System

Kepler-1802

Percentile among Sub-Neptune cohort

Radius 2.322 R⊕ · percentile 26 / cohort 1978
Mass 6.000 M⊕ · percentile 25 / cohort 1978
Orbital period 33.14 d · percentile 76 / cohort 1946
Distance 636.69 pc · percentile 55 / cohort 1975
ESI 0.675 · percentile 90 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period
33.136 days
Semi-major axis
0.1748 AU
Eccentricity
0.000
Inclination
88.87 °

Year Length

A year here lasts approximately 33.14 Earth days (9.1% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1748 AU.

Transit Fingerprint

Depth

0.083 %

Duration

4.163 h

Impact parameter b

0.444

Rp / R★

0.028324

Transit midpoint (BJD)

2,455,002.5041

Photometric dip

Transit produces a flux drop of 825 ppm lasting ≈ 4.16 h.

Extended Orbital Architecture

Planet / star radius ratio

0.028324

Semi-major axis / stellar radius

59.300

Impact parameter (b)

0.444

Transit mid-time (BJD)

2,455,002.5041

Angular separation (arcsec)

0.27500

Eq. Temperature

357K

(84 °C)

Insolation (S⊕)

3.86

Earth = 1.00

Earth Similarity (ESI)

0.675

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — liquid water is physically possible with adequate atmospheric pressure. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Valizadegan et al. 2022

Instrument

Kepler CCD Array

Publication

2022-02

Observation locale

Space

Host System: Kepler-1802

Spectral Class

K-type orange

Effective Temperature

4,245 K — cooler than the Sun (5,778 K)

Estimated Age

13.90 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.637 R☉

Stellar Mass

0.649 M☉

Metallicity [Fe/H]

0.00

Extended Stellar Properties

Surface gravity (log g)

4.641 dex

Stellar density

1.107 g/cm³

Metallicity ratio

[Fe/H]

Distance
636.69 parsec
Light-years 2,076.62 ly
V-band magnitude
15.91 mag
Voyager-speed travel 36,621,116 yr

Multi-band Host Photometry — 12 bands

12.417.117.13B15.91V16.51Gaia15.67Kepler16.08TESS16.82Sloan g15.61Sloan r15.18Sloan i14.94Sloan z13.73J13.11H12.40K

Astrometric Data

Parallax

1.554 mas

Total Proper Motion

8.141 mas/yr

PM Right Ascension

-1.54 mas/yr

PM Declination

-7.99 mas/yr

Galactic Cartesian (pc)

x = 0.361 · y = -0.620 · z = 0.696

Equatorial (J2000)

RA 300.24209° · Dec 44.14129°

Galactic ℓ, b

79.269° · 7.282°

Ecliptic λ, β

321.083° · 62.321°

HTM-20 index

-1720396576

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