Star with a known planet

tau Gem

tau Gem, a K2 III star, has one confirmed planet.

Measured

Distance
about 367 light-years
Star's spectral type
K2 III
Confirmed planets
1

How far, from the Sun

About 367 light-years. To cross it:

  • Light367 years
  • Voyager 1's speed6.52 million years
  • Driving at 100 km/h3.96 billion years

Voyager 1 at the speed it moved outward over the year to 2026-10-25 (JPL Horizons). Driving: nonstop, never refuelling.

How it was found

  • First planet found in 2013, by radial velocity (NASA Exoplanet Archive).

Its planets

  • tau Gem b — 12 times Earth's width (estimated from its mass, not measured), a giant, Jupiter-sized or more; its year lasts 310 days; about 740 °C, hotter than boiling water; found in 2013 by radial velocity.

The NASA Exoplanet Archive's page

Where this comes from

  • NASA Exoplanet Archive, Planetary Systems Composite Parameters (fetched 2026-11-02). Composite values: where a planet's size or mass was not measured, the archive estimates it from the other.
  • 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.

Every catalogue Ouranos draws is credited on the credits page.