Tau Ceti
Where is Tau Ceti?
Look south, about 23° up at 01:45 in Cetus.
- Rises
- 21:07
- Highest
- 01:47
- Sets
- 06:26
- Best after dark
- 01:45 · 23°
Can I see Tau Ceti?
No. The planets of Tau Ceti can’t be seen with the eye, binoculars or any amateur telescope: they are lost in their star’s light. What you can do is point toward the star.
From London tonight, the star Tau Ceti is above the horizon after dark. It’s highest after dark at 01:45, in the south at 23°.
Why is Tau Ceti interesting?
Tau Ceti has 3 known planets, discovered between 2012 and 2017 by the radial velocity method.
2 of them are close to Earth’s size or mass, based on the catalog values.
At about 12 light-years, it is one of the closest planetary systems to the Sun.
What can you see?
Eyes
Direction onlyAround magnitude 3.5: visible to the naked eye from most suburban skies.
Binoculars
A yellowish star.
Telescope
A single star. The planets themselves can’t be seen with any backyard telescope.
About
Tau Ceti is one of the nearest Sun-like stars, about 12 light-years away. It is slightly smaller and cooler than the Sun, and it is surrounded by a thick disk of dust and debris.
Several candidate planets have been reported from tiny wobbles in the star’s motion, some of them near the habitable zone. They are difficult to confirm and remain debated.
In 1960, Tau Ceti and Epsilon Eridani were the first targets of Project Ozma, an early search for radio signals from other civilizations. Tau Ceti has been a favorite of science fiction ever since.
Tau Ceti has about three-quarters of the Sun’s mass and is a single star, unlike many nearby stars. Its debris disk holds much more dust than our Kuiper Belt, so its planets may face more impacts.
Because it is so similar to the Sun and so close, Tau Ceti will remain a prime target for future telescopes searching for small planets.
The Tau Ceti system
| Planet | Mass | Radius | Orbit | From star | Found | Method |
|---|---|---|---|---|---|---|
| tau Cet g | 1.75 M⊕ | — | 20.0 days | 0.133 AU | 2017 | Radial Velocity |
| tau Cet h | 1.84 M⊕ | — | 49.4 days | 0.243 AU | 2017 | Radial Velocity |
| tau Cet f | 3.94 M⊕ | — | 636.1 days | 1.334 AU | 2012 | Radial Velocity |
Questions
Does Tau Ceti have planets?
Can I see Tau Ceti?
Sources: The Extrasolar Planets Encyclopaedia (CC BY 4.0); star chart: Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences