Key parameters at a glance

A radius of 3.94 Earth radii
A mass of 10.18 Earth masses
Surface gravity around 0.66 g
An orbital period of 35.747 days
Semi-major axis 0.2200 AU
Equilibrium temperature 752 K (479 °C)
Distance from Earth 1,047.93 light-years
Earth Similarity Index 0.263
Travel time at Voyager 1 speed 18,480,177 years

2 siblings around EPIC 249893012

EPIC 249893012 d shares its host star with 2 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
EPIC 249893012 b	Super-Earth	1.95	8.75	3.595	1,616	2020
EPIC 249893012 c	Sub-Neptune	3.67	14.67	15.624	990	2020
EPIC 249893012 d this	Sub-Neptune	3.94	10.18	35.747	752	2020

EPIC 249893012 d Planet Profile

Physical Specs

Radius

3.94 R⊕

Radius (Jupiter)

0.352 R♃

Mass

10.18 M⊕

Mass (Jupiter)

0.032 M♃

Density

0.91 g/cm³

Surface Gravity

0.66 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.263

HZ Position Inner

Controversial No

Discovery

Year 2020

Method Transit

Facility K2

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#12of 1978

top 0.6%

This planet

3.94R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-247 d 3.94 R⊕ Kepler-874 b 3.94 R⊕ Kepler-1442 b 3.93 R⊕

Metric	Earth	EPIC 249893012 d	Jupiter
Radius (R⊕)	1.00	3.94	11.21
Mass (M⊕)	1.00	10.18	317.83
Density (g/cm³)	5.51	0.91	1.33
Surface Gravity (g)	1.00	0.66	2.53
Insolation (S⊕)	1.00	53.00	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	10.180 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 432254760

Gaia DR2

Gaia DR2 6259263137059042048

Gaia DR3

Gaia DR3 6259263137059042048

System

EPIC 249893012

Percentile among Sub-Neptune cohort

Radius 3.940 R⊕ · percentile 99 / cohort 1978

Mass 10.180 M⊕ · percentile 74 / cohort 1978

Orbital period 35.75 d · percentile 78 / cohort 1946

Distance 321.30 pc · percentile 37 / cohort 1975

ESI 0.263 · percentile 19 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

35.747 days

Semi-major axis

0.2200 AU

Eccentricity

0.150

Inclination

89.47 °

Year Length

A year here lasts approximately 35.75 Earth days (9.8% of a terrestrial year) on a mildly elliptical path at a mean orbital distance of 0.2200 AU.

Transit Fingerprint

Duration

9.560 h

Impact parameter b

0.250

Rp / R★

0.021100

Transit midpoint (BJD)

2,458,008.6520

Extended Orbital Architecture

Planet / star radius ratio

0.021100

Semi-major axis / stellar radius

27.420

Impact parameter (b)

0.250

RV semi-amplitude (K)

1.970 m/s

Transit mid-time (BJD)

2,458,008.6520

Long. of periastron (ω)

181.00°

Angular separation (arcsec)

0.68500

Eq. Temperature

752K

(479 °C)

Insolation (S⊕)

53.00

Earth = 1.00

Earth Similarity (ESI)

0.263

0 = alien, 1 = Earth-identical

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

Detection Signatures

Transit photometry

A transit dip has been observed from at least one telescope.

Radial velocity

Stellar wobble has been measured spectroscopically.

Discovery Paper

Primary reference

Hidalgo et al. 2020

Instrument

Kepler CCD Array

Publication

2020-04

Observation locale

Space

Discovery cohort

Planets confirmed in 2020 at K2 (12 shown).

EPIC 201170410.02 · Rocky Terrestrial EPIC 201757695.02 · Rocky Terrestrial K2-323 b · Sub-Neptune K2-315 b · Rocky Terrestrial K2-316 c · Super-Earth K2-318 b · Super-Earth K2-325 b · Sub-Neptune K2-317 b · Sub-Neptune K2-322 b · Super-Earth K2-319 b · Sub-Neptune K2-316 b · Super-Earth K2-324 b · Sub-Neptune

Host System: EPIC 249893012

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,430 K — cooler than the Sun (5,778 K)

Estimated Age

9.00 Gyr — older than the Sun (4.6 Gyr)

Stellar Radius

1.710 R☉

Stellar Mass

1.050 M☉

Metallicity [Fe/H]

0.20

Extended Stellar Properties

Surface gravity (log g)

3.990 dex

Stellar density

0.298 g/cm³

Systemic radial velocity

22.36 km/s

Rotational v·sin i

2.10 km/s

Rotation period

41.00 days

Metallicity ratio

[Fe/H]

Distance

321.30 parsec

Light-years 1,047.93 ly

V-band magnitude

11.43 mag

Voyager-speed travel 18,480,177 yr

Multi-band Host Photometry — 12 bands

Astrometric Data

Parallax

3.084 mas

Total Proper Motion

36.868 mas/yr

PM Right Ascension

13.55 mas/yr

PM Declination

-34.29 mas/yr

Galactic Cartesian (pc)

x = -0.638 · y = -0.714 · z = -0.288

Equatorial (J2000)

RA 228.24824° · Dec -16.72465°

Galactic ℓ, b

345.110° · 34.308°

Ecliptic λ, β

230.363° · 1.156°

HTM-20 index

-1485107263