Key parameters at a glance

A radius of 2.15 Earth radii
A mass of 5.27 Earth masses
Surface gravity around 1.14 g
An orbital period of 10.848 days
Semi-major axis 0.0800 AU
Equilibrium temperature 499 K (226 °C)
Distance from Earth 1,237.51 light-years
Earth Similarity Index 0.526
Travel time at Voyager 1 speed 21,823,561 years
Almost certainly tidally locked to its host star given the close orbit

1 sibling around Kepler-252

Kepler-252 c shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-252 b	Rocky Terrestrial	1.23	2.04	6.668	587	2014
Kepler-252 c this	Sub-Neptune	2.15	5.27	10.848	499	2014

Kepler-252 c Planet Profile

Physical Specs

Radius

2.15 R⊕

Radius (Jupiter)

0.192 R♃

Mass

5.27 M⊕

Mass (Jupiter)

0.017 M♃

Density

2.91 g/cm³

Surface Gravity

1.14 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.526

HZ Position Inner

Controversial No

Discovery

Year 2014

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1741of 1978

top 88.0%

This planet

2.15R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-256 c 2.15 R⊕ Kepler-254 c 2.15 R⊕ Kepler-120 b 2.15 R⊕

Metric	Earth	Kepler-252 c	Jupiter
Radius (R⊕)	1.00	2.15	11.21
Mass (M⊕)	1.00	5.27	317.83
Density (g/cm³)	5.51	2.91	1.33
Surface Gravity (g)	1.00	1.14	2.53
Insolation (S⊕)	1.00	20.51	0.037

Star Catalogue Identifiers

TIC

TIC 271769940

Gaia DR2

Gaia DR2 2079662785806103936

Gaia DR3

Gaia DR3 2079662785806103936

System

Kepler-252

Percentile among Sub-Neptune cohort

Radius 2.150 R⊕ · percentile 11 / cohort 1978

Mass 5.270 M⊕ · percentile 12 / cohort 1978

Orbital period 10.85 d · percentile 37 / cohort 1946

Distance 379.42 pc · percentile 40 / cohort 1975

ESI 0.526 · percentile 74 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

10.848 days

Semi-major axis

0.0800 AU

Eccentricity

0.000

Inclination

89.57 °

Year Length

A year here lasts approximately 10.85 Earth days (3.0% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.0800 AU.

Transit Fingerprint

Depth

0.174 %

Duration

2.976 h

Impact parameter b

0.170

Rp / R★

0.036938

Transit midpoint (BJD)

2,455,004.8043

Photometric dip

Transit produces a flux drop of 1,743 ppm lasting ≈ 2.98 h.

Extended Orbital Architecture

Planet / star radius ratio

0.036938

Semi-major axis / stellar radius

28.786

Impact parameter (b)

0.170

Transit mid-time (BJD)

2,455,004.8043

Angular separation (arcsec)

0.21100

Eq. Temperature

499K

(226 °C)

Insolation (S⊕)

20.51

Earth = 1.00

Earth Similarity (ESI)

0.526

0 = alien, 1 = Earth-identical

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

Discovery Paper

Primary reference

Rowe et al. 2014

Instrument

Kepler CCD Array

Publication

2014-03

Observation locale

Space

Discovery cohort

Planets confirmed in 2014 at Kepler (12 shown).

Kepler-186 e · Super-Earth Kepler-395 c · Super-Earth Kepler-220 e · Super-Earth Kepler-249 d · Super-Earth Kepler-296 f · Super-Earth Kepler-367 c · Rocky Terrestrial Kepler-296 e · Super-Earth Kepler-155 c · Sub-Neptune Kepler-138 d · Super-Earth Kepler-333 c · Rocky Terrestrial Kepler-331 d · Super-Earth Kepler-267 d · Sub-Neptune

Host System: Kepler-252

Spectral Class

M-type red dwarf

Effective Temperature

4,208 K — cooler than the Sun (5,778 K)

Estimated Age

13.90 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

0.549 R☉

Stellar Mass

0.610 M☉

Metallicity [Fe/H]

-0.13

Extended Stellar Properties

Surface gravity (log g)

4.721 dex

Stellar density

3.834 g/cm³

Metallicity ratio

[Fe/H]

Distance

379.42 parsec

Light-years 1,237.51 ly

V-band magnitude

15.41 mag

Voyager-speed travel 21,823,561 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

2.607 mas

Total Proper Motion

10.546 mas/yr

PM Right Ascension

-2.49 mas/yr

PM Declination

-10.25 mas/yr

Galactic Cartesian (pc)

x = 0.308 · y = -0.643 · z = 0.701

Equatorial (J2000)

RA 295.57933° · Dec 44.54591°

Galactic ℓ, b

77.959° · 10.382°

Ecliptic λ, β

314.714° · 64.066°

HTM-20 index

-1131115693