Key parameters at a glance

A radius of 12.67 Earth radii
An orbital period of 4.002 days
Semi-major axis 0.0506 AU
Equilibrium temperature 1,238 K (965 °C)
Distance from Earth 2,858.97 light-years
Earth Similarity Index 0.038
Travel time at Voyager 1 speed 50,417,922 years

K2-253 b Planet Profile

Physical Specs

Radius

12.67 R⊕

Radius (Jupiter)

1.130 R♃

Mass

— M⊕

Mass (Jupiter)

— M♃

Density

— g/cm³

Surface Gravity

— g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.038

HZ Position Inner

Controversial No

Discovery

Year 2018

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#1168of 1771

top 65.9%

This planet

12.67R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

Kepler-434 b 12.67 R⊕ HATS-50 b 12.67 R⊕ HD 189733 b 12.67 R⊕

Metric	Earth	K2-253 b	Jupiter
Radius (R⊕)	1.00	12.67	11.21
Mass (M⊕)	1.00	—	317.83
Density (g/cm³)	5.51	—	1.33
Surface Gravity (g)	1.00	—	2.53
Insolation (S⊕)	1.00	365.82	0.037

Star Catalogue Identifiers

TIC

TIC 98669309

Gaia DR2

Gaia DR2 3584368019189709952

Gaia DR3

Gaia DR3 3584368019189709952

System

K2-253

Percentile among Gas Giant cohort

Radius 12.670 R⊕ · percentile 34 / cohort 1771

Orbital period 4.00 d · percentile 29 / cohort 1533

Distance 876.57 pc · percentile 85 / cohort 1759

ESI 0.038 · percentile 1 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

4.002 days

Semi-major axis

0.0506 AU

Eccentricity

—

Inclination

— °

Year Length

A year here lasts approximately 4.00 Earth days (1.1% of a terrestrial year) at a mean orbital distance of 0.0506 AU.

Transit Fingerprint

Depth

1.259 %

Duration

2.100 h

Impact parameter b

0.340

Rp / R★

0.105000

Transit midpoint (BJD)

2,457,583.9993

Photometric dip

Transit produces a flux drop of 12,590 ppm lasting ≈ 2.10 h.

Extended Orbital Architecture

Planet / star radius ratio

0.105000

Semi-major axis / stellar radius

13.900

Impact parameter (b)

0.340

Transit mid-time (BJD)

2,457,583.9993

Angular separation (arcsec)

0.05770

Eq. Temperature

1,238K

(965 °C)

Insolation (S⊕)

365.82

Earth = 1.00

Earth Similarity (ESI)

0.038

0 = alien, 1 = Earth-identical

Inside the inner HZ boundary (too hot for liquid water) — the dayside is scorched.

Discovery Paper

Primary reference

Livingston et al. 2018

Instrument

Kepler CCD Array

Publication

2018-08

Observation locale

Space

Discovery cohort

Planets confirmed in 2018 at K2 (12 shown).

K2-190 c · Rocky Terrestrial K2-183 b · Rocky Terrestrial K2-209 b · Rocky Terrestrial K2-210 b · Rocky Terrestrial K2-165 b · Super-Earth K2-169 b · Super-Earth K2-148 b · Super-Earth K2-219 b · Super-Earth K2-190 b · Super-Earth K2-200 b · Super-Earth K2-201 b · Super-Earth K2-170 b · Super-Earth

Host System: K2-253

Spectral Class

F-type yellow-white

Effective Temperature

6,027 K — hotter than the Sun (5,778 K)

Estimated Age

—

Stellar Radius

1.100 R☉

Stellar Mass

1.080 M☉

Metallicity [Fe/H]

0.00

Extended Stellar Properties

Surface gravity (log g)

4.390 dex

Stellar density

1.016 g/cm³

Metallicity ratio

[Fe/H]

Distance

876.57 parsec

Light-years 2,858.97 ly

V-band magnitude

15.00 mag

Voyager-speed travel 50,417,922 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

1.112 mas

Total Proper Motion

23.299 mas/yr

PM Right Ascension

-18.59 mas/yr

PM Declination

-14.04 mas/yr

Galactic Cartesian (pc)

x = -0.988 · y = -0.105 · z = -0.111

Equatorial (J2000)

RA 186.08531° · Dec -6.37895°

Galactic ℓ, b

290.876° · 55.857°

Ecliptic λ, β

188.108° · -3.441°

HTM-20 index

209731831