Kepler-16 A

Star

Kepler-16 A — the primary, an orange K-dwarf about 0.69 solar masses and 0.65 solar radii, ~245 light-years away in Cygnus. It is the brighter of the two suns its planet circles, locked in a 41-day eclipsing-binary dance with its small red companion.

Open in 3D viewSee Kepler-16 A in the live, interactive 3D map

Key facts

Mutual orbit
41.08 Earth days
Mass
1.37 × 10³⁰ kg
0.69 M☉
Radius
451,440 km
65% of the Sun's radius
Surface temperature
4,450 K (4177 °C)
Spectral type
K7V (orange dwarf), the brighter of the two suns

Science

Physical

Mass
1.37 × 10³⁰ kg · 0.69 M☉
Radius
451,440 km · 65% of the Sun's radius
Density
3,560 kg/m³ · 3.6× water
Spectral type
K7V (orange dwarf), the brighter of the two suns

Orbit (around the system barycenter)

Semi-major axis
7,617,628 km
Eccentricity
0.1594
Orbital period
41.1 days

Composition

By mass
An orange main-sequence star about 0.69 solar masses and 0.65 solar radii — the brighter of Kepler-16's two suns, locked in a 41-day eclipsing-binary orbit with its small red companion. Both stars' masses and sizes are pinned precisely by the mutual eclipses and the planet's transits.

Temperature

Surface
4,450 K (4177 °C)

Radiation & temperature

Luminosity
5.69 × 10²⁵ W · 0.149 L☉
Surface temperature
4,450 K (4177 °C)
Peak wavelength
651 nm · red light

Discovery & history

Name
Designated A/B for the primary and secondary of the eclipsing binary.

The brighter star of the eclipsing binary Kepler found in 2011; the mutual eclipses of A and B, plus the planet's transits of both, pinned down every mass and size precisely.

Images

Kepler-16 A and B have never been imaged as separate stars — to the eye they merge into a single point. The double-sun system is shown in the artist's concept on the planet and system view.