Key parameters at a glance

A radius of 3.48 Earth radii
A mass of 6.70 Earth masses
Surface gravity around 0.55 g
An orbital period of 31.717 days
Semi-major axis 0.1842 AU
Equilibrium temperature 550 K (277 °C)
Distance from Earth 514.29 light-years
Earth Similarity Index 0.362
Travel time at Voyager 1 speed 9,069,491 years

3 siblings around K2-32

K2-32 d shares its host star with 3 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
K2-32 e	Rocky Terrestrial	1.21	2.10	4.349	1,066	2019
K2-32 b	Neptune-like	5.30	15.00	8.992	837	2016
K2-32 c	Sub-Neptune	3.13	8.10	20.661	634	2016
K2-32 d this	Sub-Neptune	3.48	6.70	31.717	550	2016

K2-32 d Planet Profile

Physical Specs

Radius

3.48 R⊕

Radius (Jupiter)

0.311 R♃

Mass

6.70 M⊕

Mass (Jupiter)

0.021 M♃

Density

0.87 g/cm³

Surface Gravity

0.55 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.362

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#190of 1978

top 9.6%

This planet

3.48R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-103 b 3.49 R⊕ GJ 9404 b 3.48 R⊕ TOI-5076 b 3.49 R⊕

Metric	Earth	K2-32 d	Jupiter
Radius (R⊕)	1.00	3.48	11.21
Mass (M⊕)	1.00	6.70	317.83
Density (g/cm³)	5.51	0.87	1.33
Surface Gravity (g)	1.00	0.55	2.53
Insolation (S⊕)	1.00	14.80	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	6.700 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 437444661

Gaia DR2

Gaia DR2 4130539180358512768

Gaia DR3

Gaia DR3 4130539180358512768

System

K2-32

Percentile among Sub-Neptune cohort

Radius 3.484 R⊕ · percentile 90 / cohort 1978

Mass 6.700 M⊕ · percentile 36 / cohort 1978

Orbital period 31.72 d · percentile 75 / cohort 1946

Distance 157.68 pc · percentile 26 / cohort 1975

ESI 0.362 · percentile 43 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

31.717 days

Semi-major axis

0.1842 AU

Eccentricity

0.050

Inclination

89.40 °

Year Length

A year here lasts approximately 31.72 Earth days (8.7% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1842 AU.

Transit Fingerprint

Depth

0.156 %

Duration

4.888 h

Impact parameter b

0.460

Rp / R★

0.037040

Transit midpoint (BJD)

2,456,903.7871

Photometric dip

Transit produces a flux drop of 1,562 ppm lasting ≈ 4.89 h.

Extended Orbital Architecture

Planet / star radius ratio

0.037040

Semi-major axis / stellar radius

46.020

Impact parameter (b)

0.460

RV semi-amplitude (K)

1.530 m/s

Transit mid-time (BJD)

2,456,903.7871

Long. of periastron (ω)

185.00°

Angular separation (arcsec)

1.17000

Eq. Temperature

550K

(277 °C)

Insolation (S⊕)

14.80

Earth = 1.00

Earth Similarity (ESI)

0.362

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the surface is too hot to retain surface water.

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Dai et al. 2016

Instrument

Kepler CCD Array

Publication

2016-06

Observation locale

Space

Discovery cohort

Planets confirmed in 2016 at K2 (12 shown).

K2-72 d · Rocky Terrestrial K2-72 b · Rocky Terrestrial K2-91 b · Rocky Terrestrial K2-72 c · Rocky Terrestrial K2-102 b · Super-Earth K2-90 c · Super-Earth K2-72 e · Super-Earth K2-83 b · Rocky Terrestrial K2-88 b · Rocky Terrestrial K2-80 c · Super-Earth K2-83 c · Super-Earth K2-65 b · Super-Earth

Host System: K2-32

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,271 K — cooler than the Sun (5,778 K)

Estimated Age

7.90 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.860 R☉

Stellar Mass

0.830 M☉

Metallicity [Fe/H]

-0.06

Extended Stellar Properties

Surface gravity (log g)

4.490 dex

Stellar density

1.833 g/cm³

Systemic radial velocity

-2.20 km/s

Rotational v·sin i

0.70 km/s

Activity index (log R'HK)

-5.061

Metallicity ratio

[Fe/H]

Distance

157.68 parsec

Light-years 514.29 ly

V-band magnitude

12.30 mag

Voyager-speed travel 9,069,491 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

6.314 mas

Total Proper Motion

56.149 mas/yr

PM Right Ascension

-16.60 mas/yr

PM Declination

-53.64 mas/yr

Galactic Cartesian (pc)

x = -0.285 · y = -0.898 · z = -0.335

Equatorial (J2000)

RA 252.42601° · Dec -19.54305°

Galactic ℓ, b

0.546° · 15.802°

Ecliptic λ, β

253.443° · 2.892°

HTM-20 index

1677871432