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5 known planets · 1,275 light years

Kepler-139

Kepler-139 is a yellow star 1,275 light years away, with 5 confirmed planets, 1 of them in the habitable zone. Distances and orbital speeds are to scale; the star and planets are enlarged so you can see them.

Day 0
habitable zone (estimate)planet orbits

Green band: where liquid water could exist on a planet's surface. Drag to turn the system, pinch or scroll to zoom.

The star

The star

Kepler-139

Type
yellow star
Surface
≈ 5,630 K
Size
1.04 × the Sun
Mass
1.08 × the Sun
Brightness
1.04 × the Sun
Habitable zone
0.771–1.82 AU

The planets

Kepler-139

Kepler-139 d

Year
7.31 days
Distance from star
0.0756 AU
Mass
2 Earths
Size
1.7 × Earth
Temperature
≈ 972 K (+699 °C)
Found
2023, transit (Kepler)
Too hot
Kepler-139

Kepler-139 b

Year
15.77 days
Distance from star
0.127 AU
Mass
7 Earths
Size
2.9 × Earth
Temperature
≈ 752 K (+479 °C)
Found
2014, transit (Kepler)
Too hot
Kepler-139

Kepler-139 c

Year
157.07 days
Distance from star
0.586 AU
Mass
13 Earths
Size
3.4 × Earth
Temperature
≈ 350 K (+77 °C)
Found
2014, transit (Kepler)
Outside the habitable zone
Kepler-139

Kepler-139 e

Year
5.6 years
Distance from star
3.24 AU
Mass
1.2 Jupiters
Size
14 × Earth
Temperature
≈ 154 K (-119 °C)
Found
2023, radial velocity (W. M. Keck Observatory)
Outside the habitable zone
Kepler-139

Kepler-139 f

Year
355.00 days
Distance from star
1.01 AU
Mass
36 Earths
Size
6.7 × Earth
Found
2025, transit timing variations (Multiple Observatories)
In the habitable zone

Masses found by the wobble method are minimums, because the orbit's tilt is unknown. Temperatures are equilibrium estimates for a bare planet, before any atmosphere.

How we know

The wobble

The planet tugs its star back and forth. Spectrographs measure the tiny shift in the star's light, which gives the planet's year and a minimum mass.

The shadow

The planet passes in front of its star and dims it by a fraction of a percent, every orbit. The dip gives the planet's size and year.

Early and late

A known planet arrives early or late for its transits, betraying the pull of another, unseen planet.

Sources

  1. Planet and star parameters: NASA Exoplanet Archive, Planetary Systems Composite Parameters, retrieved 1 Nov 2026. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with NASA under the Exoplanet Exploration Program.
  2. Position: HYG Database v4.1 (CC BY-SA 4.0).
  3. Habitable zone: a simple estimate from the star's brightness (√L × 0.95 to 1.67 AU), shown as a guide.
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