Key parameters at a glance

A radius of 4.04 Earth radii
A mass of 15.30 Earth masses
Surface gravity around 0.94 g
An orbital period of 28.678 days
Semi-major axis 0.1867 AU
Equilibrium temperature 786 K (513 °C)
Distance from Earth 2,408.83 light-years
Earth Similarity Index 0.265
Travel time at Voyager 1 speed 42,479,801 years

K2-7 b Planet Profile

Physical Specs

Radius

4.04 R⊕

Radius (Jupiter)

0.360 R♃

Mass

15.30 M⊕

Mass (Jupiter)

0.048 M♃

Density

1.28 g/cm³

Surface Gravity

0.94 g (Earth)

Classification

Planet Type

Neptune-like

ESI Score 0.265

HZ Position Inner

Controversial No

Discovery

Year 2015

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#563of 574

top 97.9%

This planet

4.04R⊕

Neptune-like median

6.39R⊕

Nearest-size peers

Kepler-228 d 4.04 R⊕ BD-11 4672 c 4.04 R⊕ TOI-4495 c 4.03 R⊕

Metric	Earth	K2-7 b	Jupiter
Radius (R⊕)	1.00	4.04	11.21
Mass (M⊕)	1.00	15.30	317.83
Density (g/cm³)	5.51	1.28	1.33
Surface Gravity (g)	1.00	0.94	2.53
Insolation (S⊕)	1.00	125.00	0.037

Star Catalogue Identifiers

TIC

TIC 53210555

Gaia DR2

Gaia DR2 3803494845449564672

Gaia DR3

Gaia DR3 3803494845449564672

System

K2-7

Percentile among Neptune-like cohort

Radius 4.035 R⊕ · percentile 2 / cohort 574

Mass 15.300 M⊕ · percentile 8 / cohort 574

Orbital period 28.68 d · percentile 59 / cohort 524

Distance 738.55 pc · percentile 65 / cohort 572

ESI 0.265 · percentile 42 / cohort 574

Orbit & Habitability

Orbital Dynamics

Period

28.678 days

Semi-major axis

0.1867 AU

Eccentricity

0.240

Inclination

89.08 °

Year Length

A year here lasts approximately 28.68 Earth days (7.9% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.1867 AU.

Transit Fingerprint

Depth

0.058 %

Duration

7.582 h

Impact parameter b

0.370

Rp / R★

0.024080

Transit midpoint (BJD)

2,456,853.2946

Photometric dip

Transit produces a flux drop of 580 ppm lasting ≈ 7.58 h.

Extended Orbital Architecture

Planet / star radius ratio

0.024080

Semi-major axis / stellar radius

26.300

Impact parameter (b)

0.370

Transit mid-time (BJD)

2,456,853.2946

Long. of periastron (ω)

-30.00°

Angular separation (arcsec)

0.25300

Eq. Temperature

786K

(513 °C)

Insolation (S⊕)

125.00

Earth = 1.00

Earth Similarity (ESI)

0.265

0 = alien, 1 = Earth-identical

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

Discovery Paper

Primary reference

Montet et al. 2015

Instrument

Kepler CCD Array

Publication

2015-08

Observation locale

Space

Discovery cohort

Planets confirmed in 2015 at K2 (12 shown).

K2-18 b · Sub-Neptune K2-9 b · Sub-Neptune K2-3 d · Super-Earth K2-3 c · Super-Earth K2-21 c · Sub-Neptune K2-5 c · Sub-Neptune K2-13 b · Super-Earth K2-3 b · Sub-Neptune K2-17 b · Sub-Neptune K2-21 b · Super-Earth K2-16 c · Sub-Neptune K2-5 b · Super-Earth

Host System: K2-7

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,700 K — cooler than the Sun (5,778 K)

Estimated Age

8.60 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.533 R☉

Stellar Mass

1.056 M☉

Metallicity [Fe/H]

0.05

Extended Stellar Properties

Surface gravity (log g)

4.092 dex

Stellar density

0.416 g/cm³

Metallicity ratio

[Fe/H]

Distance

738.55 parsec

Light-years 2,408.83 ly

V-band magnitude

13.45 mag

Voyager-speed travel 42,479,801 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

1.325 mas

Total Proper Motion

24.133 mas/yr

PM Right Ascension

-4.64 mas/yr

PM Declination

-23.68 mas/yr

Galactic Cartesian (pc)

x = -0.975 · y = 0.223 · z = -0.019

Equatorial (J2000)

RA 167.09375° · Dec -1.06586°

Galactic ℓ, b

257.434° · 52.456°

Ecliptic λ, β

168.541° · -6.079°

HTM-20 index

391271388