Artist impression of Kepler-1661 b exoplanet
Confirmed Exoplanet Discovered 2020 Habitable Zone

Kepler-1661 b

A sub-neptune orbiting the k-type orange Kepler-1661, located approximately 1,339.2 light-years from Earth.

Image: Wikimedia Commons · Public domain · NASA Ames/JPL-Caltech

Key parameters at a glance

  • A radius of 3.87 Earth radii
  • A mass of 17.00 Earth masses
  • Surface gravity around 1.14 g
  • An orbital period of 175.060 days
  • Semi-major axis 0.6330 AU
  • Equilibrium temperature 243 K (-30 °C)
  • Distance from Earth 1,339.22 light-years
  • Earth Similarity Index 0.583
  • Travel time at Voyager 1 speed 23,617,132 years

Context from the literature

The list of exoplanets detected by the Kepler space telescope contains bodies with a wide variety of properties, with significant ranges in orbital distances, masses, radii, composition, habitability, and host star type. As of June 16 2023, the Kepler space telescope and its follow-up observations have detected 2,778 planets, including hot Jupiters, super-Earths, circumbinary planets, and planets located in the circumstellar habitable zones of their host stars. Kepler has detected over 3,601 unconfirmed planet candidates and 2,165 eclipsing binary stars.

Excerpted from Wikipedia · full article

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Circumbinary planet

Kepler-1661 b orbits a binary-star pair rather than a single host — a minority architecture in the confirmed catalogue.

Kepler-1661 b Planet Profile

Physical Specs

Radius
3.87 R⊕
Radius (Jupiter)
0.345 R♃
Mass
17.00 M⊕
Mass (Jupiter)
0.053 M♃
Density
1.60 g/cm³
Surface Gravity
1.14 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.583
HZ Position Habitable
Controversial No

Discovery

Year 2020
Method Transit
Facility Kepler
Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#38of 1978

top 1.9%

This planet

3.87R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Metric Earth Kepler-1661 b Jupiter
Radius (R⊕)1.003.8711.21
Mass (M⊕)1.0017.00317.83
Density (g/cm³)5.511.601.33
Surface Gravity (g)1.001.142.53
Insolation (S⊕)1.000.880.037

Alternative Mass Estimates

Method Value Interpretation
Best measured mass 17.000 M⊕ Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 164886585

Gaia DR2

Gaia DR2 2104078025612319360

Gaia DR3

Gaia DR3 2104078025612319360

System

Kepler-1661

Percentile among Sub-Neptune cohort

Radius 3.870 R⊕ · percentile 98 / cohort 1978
Mass 17.000 M⊕ · percentile 94 / cohort 1978
Orbital period 175.06 d · percentile 98 / cohort 1946
Distance 410.61 pc · percentile 42 / cohort 1975
ESI 0.583 · percentile 80 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period
175.060 days
Semi-major axis
0.6330 AU
Eccentricity
0.057
Inclination
89.46 °

Year Length

A year here lasts approximately 175.06 Earth days (47.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.6330 AU.

Transit Fingerprint

Rp / R★

0.046510

Transit midpoint (BJD)

2,456,007.1000

Extended Orbital Architecture

Planet / star radius ratio

0.046510

Transit mid-time (BJD)

2,456,007.1000

Long. of periastron (ω)

67.10°

Angular separation (arcsec)

1.54000

Eq. Temperature

243K

(-30 °C)

Insolation (S⊕)

0.88

Earth = 1.00

Earth Similarity (ESI)

0.583

0 = alien, 1 = Earth-identical

Within the conservative habitable zone — surface water would be frozen.

Discovery Paper

Primary reference

Socia et al. 2020

Instrument

Kepler CCD Array

Publication

2020-03

Observation locale

Space

Host System: Kepler-1661

Spectral Class

K-type orange

Effective Temperature

5,100 K — cooler than the Sun (5,778 K)

Estimated Age

2.00 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.762 R☉

Stellar Mass

0.841 M☉

Metallicity [Fe/H]

-0.12

Extended Stellar Properties

Surface gravity (log g)

4.660 dex

Stellar density

4.626 g/cm³

Rotational v·sin i

2.50 km/s

Rotation period

24.44 days

Metallicity ratio

[M/H]

Distance
410.61 parsec
Light-years 1,339.22 ly
V-band magnitude
14.36 mag
Voyager-speed travel 23,617,132 yr

Multi-band Host Photometry — 16 bands

8.815.415.38B14.36V14.19Gaia14.22Kepler13.58TESS15.00Sloan g14.16Sloan r13.88Sloan i13.74Sloan z12.73J12.22H12.16K12.07W112.11W211.70W38.76W4

Astrometric Data

Parallax

2.407 mas

Total Proper Motion

27.603 mas/yr

PM Right Ascension

-7.99 mas/yr

PM Declination

-26.42 mas/yr

Galactic Cartesian (pc)

x = 0.195 · y = -0.718 · z = 0.669

Equatorial (J2000)

RA 285.16709° · Dec 41.96694°

Galactic ℓ, b

72.265° · 16.157°

Ecliptic λ, β

296.365° · 64.024°

HTM-20 index

2139885455

Wikipedia → Image: Wikimedia Commons · NASA Ames/JPL-Caltech · Public domain

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