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1 known planet · 4,313 light years

BD+20 274

BD+20 274 is a giant star (K5 III) 4,313 light years away, with 1 confirmed planet. 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

BD+20 274

Type
K5 III
Surface
≈ 4,296 K
Size
17.30 × the Sun
Mass
0.80 × the Sun
Brightness
91.2 × the Sun
Habitable zone
7.69–19.2 AU

The planets

BD+20 274

BD+20 274 b

Year
578.20 days
Distance from star
1.3 AU
Mass
at least 4.2 Jupiters
Size
13 × Earth
Temperature
≈ 756 K (+483 °C)
Found
2012, radial velocity (McDonald Observatory)
Too hot

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.

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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