Key parameters at a glance

A radius of 13.79 Earth radii
A mass of 349.61 Earth masses
Surface gravity around 1.84 g
An orbital period of 17.855 days
Semi-major axis 0.1540 AU
Equilibrium temperature 911 K (638 °C)
Distance from Earth 1,302.66 light-years
Earth Similarity Index 0.151
Travel time at Voyager 1 speed 22,972,417 years

1 sibling around KOI-12

KOI-12 b shares its host star with 1 other confirmed planet. Side-by-side measurements below.

Planet	Type	Radius (R⊕)	Mass (M⊕)	Period (d)	Eq. T (K)	Year
KOI-12 b this	Gas Giant	13.79	349.61	17.855	911	2015
Kepler-448 c	Gas Giant	12.00	6,992.26	2,500.000	—	2017

KOI-12 b Planet Profile

Physical Specs

Radius

13.79 R⊕

Radius (Jupiter)

1.230 R♃

Mass

349.61 M⊕

Mass (Jupiter)

1.100 M♃

Density

0.73 g/cm³

Surface Gravity

1.84 g (Earth)

Classification

Planet Type

Gas Giant

ESI Score 0.151

HZ Position Inner

Controversial No

Discovery

Year 2015

Method Transit

Facility Kepler

Telescope 0.95 m Kepler Telescope

Size rank in cohort

Rank by radius

#540of 1771

top 30.4%

This planet

13.79R⊕

Gas Giant median

13.52R⊕

Nearest-size peers

WASP-192 b 13.79 R⊕ HATS-33 b 13.79 R⊕ WASP-38 b 13.79 R⊕

Metric	Earth	KOI-12 b	Jupiter
Radius (R⊕)	1.00	13.79	11.21
Mass (M⊕)	1.00	349.61	317.83
Density (g/cm³)	5.51	0.73	1.33
Surface Gravity (g)	1.00	1.84	2.53
Insolation (S⊕)	1.00	196.51	0.037

Alternative Mass Estimates

Method	Value	Interpretation
Best measured mass	349.613 M⊕	Direct mass measurement (not derived).

Star Catalogue Identifiers

TIC

TIC 169461816

Gaia DR2

Gaia DR2 2073860662955260416

Gaia DR3

Gaia DR3 2073860662955260416

System

KOI-12

Percentile among Gas Giant cohort

Radius 13.787 R⊕ · percentile 69 / cohort 1771

Mass 349.613 M⊕ · percentile 38 / cohort 1747

Orbital period 17.86 d · percentile 47 / cohort 1533

Distance 399.40 pc · percentile 70 / cohort 1759

ESI 0.151 · percentile 36 / cohort 1771

Orbit & Habitability

Orbital Dynamics

Period

17.855 days

Semi-major axis

0.1540 AU

Eccentricity

0.340

Inclination

88.95 °

Year Length

A year here lasts approximately 17.86 Earth days (4.9% of a terrestrial year) on a highly eccentric trajectory at a mean orbital distance of 0.1540 AU.

Transit Fingerprint

Depth

0.907 %

Duration

7.429 h

Impact parameter b

0.371

Rp / R★

0.088385

Transit midpoint (BJD)

2,454,979.5964

Photometric dip

Transit produces a flux drop of 9,065 ppm lasting ≈ 7.43 h.

Extended Orbital Architecture

Planet / star radius ratio

0.088385

Semi-major axis / stellar radius

19.993

Impact parameter (b)

0.371

RV semi-amplitude (K)

800.000 m/s

Transit mid-time (BJD)

2,454,979.5964

Long. of periastron (ω)

228.00°

Sky-projected obliquity (λ)

12.60°

Angular separation (arcsec)

0.38600

Eq. Temperature

911K

(638 °C)

Insolation (S⊕)

196.51

Earth = 1.00

Earth Similarity (ESI)

0.151

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.

Transit timing variations

Gravitational interactions from neighbours have been detected.

Discovery Paper

Primary reference

Bourrier et al. 2015

Instrument

Kepler CCD Array

Publication

2015-07

Observation locale

Space

Discovery cohort

Planets confirmed in 2015 at Kepler (12 shown).

Kepler-438 b · Rocky Terrestrial Kepler-445 d · Super-Earth Kepler-442 b · Super-Earth Kepler-439 b · Sub-Neptune Kepler-437 b · Sub-Neptune Kepler-440 b · Super-Earth KIC 8540376 c · Sub-Neptune Kepler-445 b · Super-Earth Kepler-446 d · Super-Earth Kepler-436 b · Sub-Neptune Kepler-445 c · Sub-Neptune Kepler-443 b · Sub-Neptune

Host System: KOI-12

Spectral Class

F-type yellow-white

Effective Temperature

6,635 K — hotter than the Sun (5,778 K)

Estimated Age

1.45 Gyr — younger than the Sun (4.6 Gyr)

Stellar Radius

1.400 R☉

Stellar Mass

1.500 M☉

Metallicity [Fe/H]

0.08

Extended Stellar Properties

Surface gravity (log g)

4.308 dex

Stellar density

0.800 g/cm³

Systemic radial velocity

-14.68 km/s

Rotational v·sin i

60.00 km/s

Metallicity ratio

[M/H]

Distance

399.40 parsec

Light-years 1,302.66 ly

V-band magnitude

11.51 mag

Voyager-speed travel 22,972,417 yr

Multi-band Host Photometry — 16 bands

Astrometric Data

Parallax

2.475 mas

Total Proper Motion

3.999 mas/yr

PM Right Ascension

3.04 mas/yr

PM Declination

2.60 mas/yr

Galactic Cartesian (pc)

x = 0.348 · y = -0.670 · z = 0.656

Equatorial (J2000)

RA 297.45374° · Dec 41.01102°

Galactic ℓ, b

75.499° · 7.470°

Ecliptic λ, β

314.552° · 60.274°

HTM-20 index

-946880236