Key parameters at a glance

A radius of 1.60 Earth radii
A mass of 3.20 Earth masses
Surface gravity around 1.25 g
An orbital period of 4.868 days
Semi-major axis 0.0434 AU
Distance from Earth 245.17 light-years
Earth Similarity Index 0.867
Travel time at Voyager 1 speed 4,323,616 years
Almost certainly tidally locked to its host star given the close orbit

3 siblings around K2-133

K2-133 c 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
K2-133 b	Super-Earth	1.34	2.36	3.071	—	2017
K2-133 c this	Super-Earth	1.60	3.20	4.868	—	2017
K2-133 d	Sub-Neptune	2.00	4.67	11.025	734	2017
K2-133 e	Super-Earth	1.73	3.64	26.584	296	2019

K2-133 c Planet Profile

Physical Specs

Radius

1.60 R⊕

Radius (Jupiter)

0.143 R♃

Mass

3.20 M⊕

Mass (Jupiter)

0.010 M♃

Density

4.27 g/cm³

Surface Gravity

1.25 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.867

HZ Position Unknown

Controversial No

Discovery

Year 2017

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#567of 1176

top 48.1%

This planet

1.60R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

HD 219134 b 1.60 R⊕ Kepler-1702 b 1.60 R⊕ Kepler-394 b 1.60 R⊕

Metric	Earth	K2-133 c	Jupiter
Radius (R⊕)	1.00	1.60	11.21
Mass (M⊕)	1.00	3.20	317.83
Density (g/cm³)	5.51	4.27	1.33
Surface Gravity (g)	1.00	1.25	2.53
Insolation (S⊕)	1.00	—	0.037

Star Catalogue Identifiers

TIC

TIC 150096001

Gaia DR2

Gaia DR2 148080473682357376

Gaia DR3

Gaia DR3 148080473682357376

System

K2-133

Percentile among Super-Earth cohort

Radius 1.603 R⊕ · percentile 52 / cohort 1176

Mass 3.200 M⊕ · percentile 47 / cohort 1176

Orbital period 4.87 d · percentile 39 / cohort 1164

Distance 75.17 pc · percentile 15 / cohort 1171

ESI 0.867 · percentile 95 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

4.868 days

Semi-major axis

0.0434 AU

Eccentricity

—

Inclination

88.21 °

Year Length

A year here lasts approximately 4.87 Earth days (1.3% of a terrestrial year) at a mean orbital distance of 0.0434 AU.

Transit Fingerprint

Depth

0.098 %

Duration

1.620 h

Impact parameter b

0.640

Rp / R★

0.032300

Transit midpoint (BJD)

2,457,823.7686

Photometric dip

Transit produces a flux drop of 980 ppm lasting ≈ 1.62 h.

Extended Orbital Architecture

Planet / star radius ratio

0.032300

Impact parameter (b)

0.640

Transit mid-time (BJD)

2,457,823.7686

Angular separation (arcsec)

0.57700

Eq. Temperature

—

Insolation (S⊕)

—

Earth = 1.00

Earth Similarity (ESI)

0.867

0 = alien, 1 = Earth-identical

Insufficient insolation data. Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Wells et al. 2018

Instrument

Kepler CCD Array

Publication

2018-01

Observation locale

Space

Discovery cohort

Planets confirmed in 2017 at K2 (12 shown).

K2-129 b · Rocky Terrestrial K2-130 b · Super-Earth K2-133 b · Super-Earth K2-128 b · Super-Earth K2-116 b · Rocky Terrestrial K2-125 b · Sub-Neptune K2-118 b · Sub-Neptune K2-136 d · Super-Earth K2-123 b · Sub-Neptune K2-136 c · Sub-Neptune K2-124 b · Sub-Neptune K2-117 c · Sub-Neptune

Host System: K2-133

Spectral Class

M-type red dwarf

Effective Temperature

3,655 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.455 R☉

Stellar Mass

0.461 M☉

Metallicity [Fe/H]

—

Extended Stellar Properties

Surface gravity (log g)

4.770 dex

Stellar density

6.630 g/cm³

Systemic radial velocity

107.20 km/s

Distance

75.17 parsec

Light-years 245.17 ly

V-band magnitude

14.07 mag

Voyager-speed travel 4,323,616 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

13.274 mas

Total Proper Motion

191.359 mas/yr

PM Right Ascension

185.66 mas/yr

PM Declination

-46.36 mas/yr

Galactic Cartesian (pc)

x = 0.308 · y = 0.852 · z = 0.423

Equatorial (J2000)

RA 70.14938° · Dec 25.00981°

Galactic ℓ, b

174.754° · -14.068°

Ecliptic λ, β

72.052° · 2.799°

HTM-20 index

-1995439910