Key parameters at a glance

A radius of 1.51 Earth radii
A mass of 2.89 Earth masses
Surface gravity around 1.27 g
An orbital period of 25.369 days
Semi-major axis 0.1752 AU
Equilibrium temperature 755 K (482 °C)
Distance from Earth 1,648.82 light-years
Earth Similarity Index 0.400
Travel time at Voyager 1 speed 29,076,934 years

Kepler-1209 b Planet Profile

Physical Specs

Radius

1.51 R⊕

Radius (Jupiter)

0.135 R♃

Mass

2.89 M⊕

Mass (Jupiter)

0.009 M♃

Density

4.61 g/cm³

Surface Gravity

1.27 g (Earth)

Classification

Planet Type

Super-Earth

ESI Score 0.400

HZ Position Inner

Controversial No

Discovery

Year 2016

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#730of 1176

top 62.0%

This planet

1.51R⊕

Super-Earth median

1.60R⊕

Nearest-size peers

Kepler-249 c 1.51 R⊕ Kepler-205 b 1.51 R⊕ Kepler-389 b 1.51 R⊕

Metric	Earth	Kepler-1209 b	Jupiter
Radius (R⊕)	1.00	1.51	11.21
Mass (M⊕)	1.00	2.89	317.83
Density (g/cm³)	5.51	4.61	1.33
Surface Gravity (g)	1.00	1.27	2.53
Insolation (S⊕)	1.00	63.25	0.037

Star Catalogue Identifiers

TIC

TIC 399953998

Gaia DR2

Gaia DR2 2131252627290713472

Gaia DR3

Gaia DR3 2131252627290713472

System

Kepler-1209

Percentile among Super-Earth cohort

Radius 1.510 R⊕ · percentile 37 / cohort 1176

Mass 2.890 M⊕ · percentile 34 / cohort 1176

Orbital period 25.37 d · percentile 89 / cohort 1164

Distance 505.53 pc · percentile 48 / cohort 1171

ESI 0.400 · percentile 60 / cohort 1176

Orbit & Habitability

Orbital Dynamics

Period

25.369 days

Semi-major axis

0.1752 AU

Eccentricity

0.000

Inclination

87.87 °

Year Length

A year here lasts approximately 25.37 Earth days (6.9% of a terrestrial year) on a nearly circular orbit at a mean orbital distance of 0.1752 AU.

Transit Fingerprint

Depth

0.011 %

Duration

4.634 h

Impact parameter b

0.057

Rp / R★

0.009812

Transit midpoint (BJD)

2,454,976.6874

Photometric dip

Transit produces a flux drop of 114 ppm lasting ≈ 4.63 h.

Extended Orbital Architecture

Planet / star radius ratio

0.009812

Semi-major axis / stellar radius

42.170

Impact parameter (b)

0.057

Transit mid-time (BJD)

2,454,976.6874

Angular separation (arcsec)

0.34600

Eq. Temperature

755K

(482 °C)

Insolation (S⊕)

63.25

Earth = 1.00

Earth Similarity (ESI)

0.400

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

Morton et al. 2016

Instrument

Kepler CCD Array

Publication

2016-05

Observation locale

Space

Discovery cohort

Planets confirmed in 2016 at Kepler (12 shown).

Kepler-1512 b · Rocky Terrestrial Kepler-1410 b · Super-Earth Kepler-560 b · Super-Earth Kepler-1389 b · Super-Earth Kepler-1450 b · Super-Earth Kepler-1544 b · Super-Earth Kepler-1459 b · Super-Earth Kepler-1638 b · Super-Earth Kepler-737 b · Super-Earth Kepler-1185 b · Super-Earth Kepler-1178 b · Rocky Terrestrial Kepler-1040 b · Sub-Neptune

Host System: Kepler-1209

Spectral Class

F-type yellow-white

Effective Temperature

6,210 K — hotter than the Sun (5,778 K)

Estimated Age

3.09 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.380 R☉

Stellar Mass

1.230 M☉

Metallicity [Fe/H]

0.12

Extended Stellar Properties

Surface gravity (log g)

4.240 dex

Stellar density

0.580 g/cm³

Systemic radial velocity

-26.47 km/s

Metallicity ratio

[Fe/H]

Distance

505.53 parsec

Light-years 1,648.82 ly

V-band magnitude

12.55 mag

Voyager-speed travel 29,076,934 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

1.950 mas

Total Proper Motion

9.742 mas/yr

PM Right Ascension

0.55 mas/yr

PM Declination

-9.73 mas/yr

Galactic Cartesian (pc)

x = 0.198 · y = -0.623 · z = 0.756

Equatorial (J2000)

RA 287.58494° · Dec 49.15473°

Galactic ℓ, b

79.885° · 17.277°

Ecliptic λ, β

306.083° · 70.399°

HTM-20 index

725256807