Kepler-16 B

Star

Kepler-16 B — the secondary, a small red M-dwarf only ~0.20 solar masses, orbiting the primary every 41 days. Faint and cool, it is the fainter of the planet's two suns; together with Kepler-16 A it makes a real double sunset possible.

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

Key facts

Mutual orbit
41.08 Earth days
Mass
4.03 × 10²⁹ kg
0.203 M☉
Radius
157,388 km
23% of the Sun's radius
Surface temperature
3,311 K (3038 °C)
Spectral type
M-dwarf (red dwarf), the fainter of the two suns

Science

Physical

Mass
4.03 × 10²⁹ kg · 0.203 M☉
Radius
157,388 km · 23% of the Sun's radius
Density
24,669 kg/m³ · 25× water
Spectral type
M-dwarf (red dwarf), the fainter of the two suns

Orbit (around the system barycenter)

Semi-major axis
0.173 AU
Eccentricity
0.1594
Orbital period
41.1 days

Composition

By mass
A small, cool red dwarf only ~0.20 solar masses, orbiting the primary every 41 days. Faint and red, it is the second of the planet's two suns — the pair that makes a real double sunset possible.

Temperature

Surface
3,311 K (3038 °C)

Radiation & temperature

Luminosity
2.12 × 10²⁴ W · 0.00554 L☉
Surface temperature
3,311 K (3038 °C)
Peak wavelength
875 nm · near-infrared (mostly invisible to the eye)

Discovery & history

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

The fainter star of the Kepler-16 eclipsing binary; its regular eclipses of the primary are what let astronomers weigh both stars — and the planet transiting them.

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.