Tau Ceti

Tau Ceti
Location of τ Ceti (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Cetus
Pronunciation /ˌt ˈst/
Right ascension 01h 44m 04.083s
Declination −15° 56 14.93
Apparent magnitude (V) 3.50±0.01
Characteristics
Evolutionary stage Main sequence
Spectral type G8V
U−B color index +0.21
B−V color index +0.72
Astrometry
Radial velocity (Rv)−16.68±0.05 km/s
Proper motion (μ) RA: −1721.728 mas/yr
Dec.: +854.963 mas/yr
Parallax (π)273.8097±0.1701 mas
Distance11.912 ± 0.007 ly
(3.652 ± 0.002 pc)
Absolute magnitude (MV)5.69±0.01
Absolute bolometric
magnitude
 (Mbol)
5.52±0.02
Details
Mass0.800±0.008 M
Radius0.793±0.004 R
Luminosity0.488±0.010 L
Luminosity (visual, LV)0.45 L
Surface gravity (log g)4.48±0.05 cgs
Temperature5,320±40 K
Metallicity28±3% Sun
Metallicity [Fe/H]−0.55±0.05 dex
Rotation46±4 d
Rotational velocity (v sin i)0.1±0.1 km/s
Age8–10 Gyr
Other designations
52 Cet, BD−16°295, FK5 59, GJ 71, HD 10700, HIP 8102, HR 509, SAO 147986, LFT 159, LHS 146, LTT 935
Database references
SIMBADdata
Exoplanet Archivedata
ARICNSdata

Tau Ceti, Latinized from τ Ceti, is a single star in the constellation Cetus that is spectrally similar to the Sun, although it has only about 78% of the Sun's mass. At a distance of just under 12 light-years (3.7 parsecs) from the Solar System, it is a relatively nearby star and the closest solitary G-class star. The star appears stable, with little stellar variation, and is metal-deficient (low in elements other than hydrogen and helium) relative to the Sun.

It can be seen with the unaided eye with an apparent magnitude of 3.5. As seen from Tau Ceti, the Sun would be in the northern hemisphere constellation Boötes with an apparent magnitude of about 2.6.

Observations have detected more than ten times as much dust surrounding Tau Ceti as is present in the Solar System. Since December 2012, there has been evidence of at least four planets—all likely super-Earths—orbiting Tau Ceti, and two of these are potentially in the habitable zone. There is evidence of up to an additional four unconfirmed planets, one of which would be a Jovian planet between 3 and 20 AU from the star. Note that those planetary candidates have been contested and recent discoveries about the stellar inclination cast doubt about the terrestrial nature of these worlds. Because of its debris disk, any planet orbiting Tau Ceti would face far more impact events than present day Earth. Despite this hurdle to habitability, its solar analog (Sun-like) characteristics have led to widespread interest in the star. Given its stability, similarity and relative proximity to the Sun, Tau Ceti is consistently listed as a target for the search for extraterrestrial intelligence (SETI).