Key parameters at a glance

A radius of 2.67 Earth radii
A mass of 7.61 Earth masses
Surface gravity around 1.07 g
An orbital period of 10.850 days
Semi-major axis 0.0914 AU
Equilibrium temperature 676 K (403 °C)
Distance from Earth 2,822.92 light-years
Earth Similarity Index 0.365
Travel time at Voyager 1 speed 49,782,179 years

Kepler-1978 b Planet Profile

Physical Specs

Radius

2.67 R⊕

Radius (Jupiter)

0.238 R♃

Mass

7.61 M⊕

Mass (Jupiter)

0.024 M♃

Density

2.20 g/cm³

Surface Gravity

1.07 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.365

HZ Position Inner

Controversial No

Discovery

Year 2023

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#904of 1978

top 45.7%

This planet

2.67R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-357 c 2.67 R⊕ Kepler-96 b 2.67 R⊕ K2-26 b 2.67 R⊕

Metric	Earth	Kepler-1978 b	Jupiter
Radius (R⊕)	1.00	2.67	11.21
Mass (M⊕)	1.00	7.61	317.83
Density (g/cm³)	5.51	2.20	1.33
Surface Gravity (g)	1.00	1.07	2.53
Insolation (S⊕)	1.00	49.30	0.037

Star Catalogue Identifiers

TIC

TIC 120693914

Gaia DR2

Gaia DR2 2099854801450635520

Gaia DR3

Gaia DR3 2099854801450635520

System

Kepler-1978

Percentile among Sub-Neptune cohort

Radius 2.670 R⊕ · percentile 53 / cohort 1978

Mass 7.610 M⊕ · percentile 49 / cohort 1978

Orbital period 10.85 d · percentile 37 / cohort 1946

Distance 865.51 pc · percentile 70 / cohort 1975

ESI 0.365 · percentile 44 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

10.850 days

Semi-major axis

0.0914 AU

Eccentricity

0.000

Inclination

88.49 °

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 0.0914 AU.

Transit Fingerprint

Depth

0.112 %

Duration

3.474 h

Impact parameter b

0.550

Rp / R★

0.031398

Transit midpoint (BJD)

2,454,969.7443

Photometric dip

Transit produces a flux drop of 1,122 ppm lasting ≈ 3.47 h.

Extended Orbital Architecture

Planet / star radius ratio

0.031398

Semi-major axis / stellar radius

20.830

Impact parameter (b)

0.550

Transit mid-time (BJD)

2,454,969.7443

Angular separation (arcsec)

0.10600

Eq. Temperature

676K

(403 °C)

Insolation (S⊕)

49.30

Earth = 1.00

Earth Similarity (ESI)

0.365

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

Valizadegan et al. 2023

Instrument

Kepler CCD Array

Publication

2023-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2023 at Kepler (12 shown).

Kepler-1126 c · Super-Earth Kepler-2000 c · Super-Earth Kepler-1052 c · Sub-Neptune Kepler-311 d · Sub-Neptune Kepler-1996 c · Sub-Neptune Kepler-1162 c · Super-Earth Kepler-1996 b · Sub-Neptune Kepler-1610 c · Sub-Neptune Kepler-1801 c · Sub-Neptune Kepler-1995 b · Neptune-like Kepler-1992 b · Rocky Terrestrial Kepler-1986 b · Super-Earth

Host System: Kepler-1978

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,251 K — cooler than the Sun (5,778 K)

Estimated Age

0.60 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

0.778 R☉

Stellar Mass

0.869 M☉

Metallicity [Fe/H]

-0.04

Extended Stellar Properties

Surface gravity (log g)

4.592 dex

Stellar density

1.453 g/cm³

Metallicity ratio

[Fe/H]

Distance

865.51 parsec

Light-years 2,822.92 ly

V-band magnitude

15.49 mag

Voyager-speed travel 49,782,179 yr

Multi-band Host Photometry — 17 bands

Astrometric Data

Parallax

1.127 mas

Total Proper Motion

5.069 mas/yr

PM Right Ascension

1.61 mas/yr

PM Declination

4.81 mas/yr

Galactic Cartesian (pc)

x = 0.217 · y = -0.757 · z = 0.616

Equatorial (J2000)

RA 286.00673° · Dec 38.00954°

Galactic ℓ, b

68.750° · 14.022°

Ecliptic λ, β

295.772° · 60.025°

HTM-20 index

656013309