Key parameters at a glance

A radius of 2.49 Earth radii
A mass of 3.70 Earth masses
Surface gravity around 0.60 g
An orbital period of 34.538 days
Semi-major axis 0.2118 AU
Equilibrium temperature 607 K (334 °C)
Distance from Earth 2,297.57 light-years
Earth Similarity Index 0.388
Travel time at Voyager 1 speed 40,517,588 years

3 siblings around Kepler-289

Kepler-289 b shares its host star with 3 other confirmed planets. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
Kepler-289 b this	Sub-Neptune	2.49	3.70	34.538	607	2014
Kepler-289 d	Sub-Neptune	3.03	5.33	66.028	—	2014
Kepler-289 c	Gas Giant	11.23	157.18	125.872	394	2014
Kepler-289 e	Sub-Neptune	2.94	17.40	330.072	286	2025

Kepler-289 b Planet Profile

Physical Specs

Radius

2.49 R⊕

Radius (Jupiter)

0.222 R♃

Mass

3.70 M⊕

Mass (Jupiter)

0.012 M♃

Density

1.45 g/cm³

Surface Gravity

0.60 g (Earth)

Classification

Planet Type

Sub-Neptune

ESI Score 0.388

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

#1191of 1978

top 60.2%

This planet

2.49R⊕

Sub-Neptune median

2.71R⊕

Nearest-size peers

Kepler-184 d 2.49 R⊕ HD 176986 d 2.49 R⊕ Kepler-11 f 2.49 R⊕

Metric	Earth	Kepler-289 b	Jupiter
Radius (R⊕)	1.00	2.49	11.21
Mass (M⊕)	1.00	3.70	317.83
Density (g/cm³)	5.51	1.45	1.33
Surface Gravity (g)	1.00	0.60	2.53
Insolation (S⊕)	1.00	27.37	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	3.700 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 273234825

Gaia DR2

Gaia DR2 2078515170549178880

Gaia DR3

Gaia DR3 2078515170549178880

System

Kepler-289

Percentile among Sub-Neptune cohort

Radius 2.490 R⊕ · percentile 39 / cohort 1978

Mass 3.700 M⊕ · percentile 1 / cohort 1978

Orbital period 34.54 d · percentile 77 / cohort 1946

Distance 704.44 pc · percentile 60 / cohort 1975

ESI 0.388 · percentile 50 / cohort 1978

Orbit & Habitability

Orbital Dynamics

Period

34.538 days

Semi-major axis

0.2118 AU

Eccentricity

0.000

Inclination

88.98 °

Year Length

A year here lasts approximately 34.54 Earth days (9.5% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.2118 AU.

Transit Fingerprint

Depth

0.043 %

Duration

3.178 h

Impact parameter b

0.825

Rp / R★

0.022800

Transit midpoint (BJD)

2,454,965.6879

Photometric dip

Transit produces a flux drop of 430 ppm lasting ≈ 3.18 h.

Extended Orbital Architecture

Planet / star radius ratio

0.022800

Semi-major axis / stellar radius

46.380

Impact parameter (b)

0.825

Transit mid-time (BJD)

2,454,965.6879

Angular separation (arcsec)

0.30100

Eq. Temperature

607K

(334 °C)

Insolation (S⊕)

27.37

Earth = 1.00

Earth Similarity (ESI)

0.388

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.

Transit timing variations

Gravitational interactions from neighbours have been detected.

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-289

Spectral Class

G-type yellow (Sun-like)

Effective Temperature

5,990 K — hotter than the Sun (5,778 K)

Estimated Age

0.65 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.000 R☉

Stellar Mass

1.080 M☉

Metallicity [Fe/H]

0.05

Extended Stellar Properties

Surface gravity (log g)

4.470 dex

Stellar density

1.580 g/cm³

Metallicity ratio

[Fe/H]

Distance

704.44 parsec

Light-years 2,297.57 ly

V-band magnitude

14.14 mag

Voyager-speed travel 40,517,588 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.391 mas

Total Proper Motion

4.785 mas/yr

PM Right Ascension

4.78 mas/yr

PM Declination

-0.24 mas/yr

Galactic Cartesian (pc)

x = 0.338 · y = -0.650 · z = 0.681

Equatorial (J2000)

RA 297.46534° · Dec 42.88285°

Galactic ℓ, b

77.147° · 8.386°

Ecliptic λ, β

316.043° · 62.002°

HTM-20 index

1432308909