Kepler-22

Star

Kepler-22 — a Sun-like G-type star a little smaller and cooler than the Sun, ~635 light-years away in Cygnus. Ordinary in itself, it became a landmark as the host of the first planet confirmed in the habitable zone of a Sun-like star.

Open in 3D viewSee Kepler-22 in the live, interactive 3D map

Key facts

Mass

1.70 × 10³⁰ kg

0.857 M☉

Radius

604,563 km

87% of the Sun's radius

Science

Physical

Mass: 1.70 × 10³⁰ kg · 0.857 M☉
Radius: 604,563 km · 87% of the Sun's radius
Density: 1,842 kg/m³ · 1.8× water; Computed from mass and radius

Motion through space

Proper motion: 0.0776 arcseconds per year · its drift across our sky; SIMBAD — 2020yCat.1350....0G, 2020AJ....160..120J
Radial velocity: -3.6 km/s · approaching the Sun; SIMBAD — 2020yCat.1350....0G, 2020AJ....160..120J
Speed across our line of sight: 72.7 km/s; Computed from proper motion and parallax
Speed through space, relative to the Sun: 72.8 km/s; Computed from proper motion, parallax and radial velocity

Radiation & temperature

Luminosity: 2.55 × 10²⁶ W · 0.667 L☉

Discovery & history

Method: Telescope
Name: A Kepler-mission catalogue designation; no proper name.

Watched by NASA's Kepler telescope, its light revealed a planet transiting in the temperate zone; the 2011 confirmation was a milestone in the hunt for another Earth.

Images

Where to find it — in Cygnus, the Swan (IAU constellation chart). To the eye it is a single point of light; no telescope has imaged its surface. — IAU / Sky & Telescope, R. Sinnott & R. Fienberg (CC BY 3.0) · Wikimedia Commons

Images from open archives · credit shown per image