Key parameters at a glance

A radius of 1.23 Earth radii
A mass of 2.04 Earth masses
Surface gravity around 1.35 g
An orbital period of 4.612 days
Semi-major axis 0.0345 AU
Distance from Earth 360.60 light-years
Earth Similarity Index 0.934
Travel time at Voyager 1 speed 6,359,204 years
Almost certainly tidally locked to its host star given the close orbit

K2-88 b Planet Profile

Physical Specs

Radius

1.23 R⊕

Radius (Jupiter)

0.110 R♃

Mass

2.04 M⊕

Mass (Jupiter)

0.006 M♃

Density

6.02 g/cm³

Surface Gravity

1.35 g (Earth)

Classification

Planet Type

Rocky Terrestrial

ESI Score 0.934

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

#17of 570

top 2.8%

This planet

1.23R⊕

Rocky Terrestrial median

1.01R⊕

Nearest-size peers

Kepler-252 b 1.23 R⊕ Kepler-271 b 1.23 R⊕ Kepler-197 c 1.23 R⊕

Metric	Earth	K2-88 b	Jupiter
Radius (R⊕)	1.00	1.23	11.21
Mass (M⊕)	1.00	2.04	317.83
Density (g/cm³)	5.51	6.02	1.33
Surface Gravity (g)	1.00	1.35	2.53
Insolation (S⊕)	1.00	7.80	0.037

Star Catalogue Identifiers

TIC

TIC 113979956

Gaia DR2

Gaia DR2 56983706234931328

Gaia DR3

Gaia DR3 56983706234931328

System

K2-88

Percentile among Rocky Terrestrial cohort

Radius 1.230 R⊕ · percentile 94 / cohort 570

Mass 2.040 M⊕ · percentile 86 / cohort 570

Orbital period 4.61 d · percentile 50 / cohort 567

Distance 110.56 pc · percentile 25 / cohort 566

ESI 0.934 · percentile 91 / cohort 570

Orbit & Habitability

Orbital Dynamics

Period

4.612 days

Semi-major axis

0.0345 AU

Eccentricity

0.260

Inclination

87.75 °

Year Length

A year here lasts approximately 4.61 Earth days (1.3% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.0345 AU.

Transit Fingerprint

Depth

0.219 %

Duration

1.039 h

Rp / R★

0.043600

Transit midpoint (BJD)

2,457,066.2194

Photometric dip

Transit produces a flux drop of 2,194 ppm lasting ≈ 1.04 h.

Extended Orbital Architecture

Planet / star radius ratio

0.043600

Semi-major axis / stellar radius

19.980

Transit mid-time (BJD)

2,457,066.2194

Long. of periastron (ω)

72.02°

Angular separation (arcsec)

0.31200

Eq. Temperature

—

Insolation (S⊕)

7.80

Earth = 1.00

Earth Similarity (ESI)

0.934

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water). Close-orbiting tidally-locked around a cool host.

Discovery Paper

Primary reference

Crossfield et al. 2016

Instrument

Kepler CCD Array

Publication

2016-09

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 K2-80 c · Super-Earth K2-83 c · Super-Earth K2-65 b · Super-Earth K2-68 b · Super-Earth

Host System: K2-88

Spectral Class

M-type red dwarf

Effective Temperature

3,537 K — cooler than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

0.256 R☉

Stellar Mass

0.258 M☉

Metallicity [Fe/H]

—

Distance

110.56 parsec

Light-years 360.60 ly

V-band magnitude

15.52 mag

Voyager-speed travel 6,359,204 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

9.017 mas

Total Proper Motion

53.940 mas/yr

PM Right Ascension

-24.61 mas/yr

PM Declination

-48.00 mas/yr

Galactic Cartesian (pc)

x = 0.545 · y = 0.772 · z = 0.328

Equatorial (J2000)

RA 54.75146° · Dec 19.11997°

Galactic ℓ, b

168.792° · -28.464°

Ecliptic λ, β

56.951° · -0.367°

HTM-20 index

1829782501