Confirmed exoplanet · Database record + computed analysis
tau Cet h
A confirmed world orbiting tau Cet, 11.8 light-years away.
An Earth-sized world
1.19 times Earth's radius, squarely in the terrestrial size range. With 1.8 Earth masses packed into that size, its density points to rock and iron rather than gas.
The orbit
Its year, one full orbit, takes just 49.4 Earth days.
Temperature and starlight
Its equilibrium temperature (the airless-world estimate) is about 200 °C. Above water's boiling point. It receives 8.4 times the starlight Earth gets.
Its sun
Its star is Sun-like (5,310 K, G8.5V; the Sun is 5,772 K). It shares the system with 2 other known planets.
How far is that, really?
At 12 light-years, tonight's light from this system left it around the year 2014. That is close by galactic standards, which makes it a prime target for follow-up telescopes. A Voyager-speed probe would need roughly 207,915 years to get there.
How we found it
It was found by the radial-velocity method: the planet's gravity swings its star in a small circle, and that wobble shows up as a rhythmic Doppler shift in the starlight. The wobble's size gives the planet's minimum mass. The discovery was announced in 2017 from Multiple Observatories.
Everything above is computed from the archive’s measured values for this planet. Where a quantity is missing, the statement is omitted rather than guessed.
About this record
The measured values come from the NASA Exoplanet Archive, and any missing value has not been determined yet; the Atlas never fills gaps with guesses. More standout worlds: Proxima b, TRAPPIST-1e, K2-18 b, 55 Cancri e, and the detection methods that found them all.