Tau Ceti (HD 10700 / 52 Ceti)
Coordinates, Gaia DR3 parallax (273.81 mas, 11.91 ly), magnitude 3.50, debris disk, and observing guide for G8V star Tau Ceti.
Provenance-Backed Scientific Measurements
Every measurement below preserves its unit, uncertainty interval, observational method, reference epoch, quality status, and primary catalog source. See Uncertainty & Provenance for how competing measurements are handled.
| Parameter | Value | Uncertainty | Method & Epoch | Quality Status | Source Archive |
|---|---|---|---|---|---|
| Trigonometric parallax (Gaia DR3) | 273.8097 mas | ± 0.1701 mas | Gaia DR3 five-parameter astrometric solution (J2016.0) | definitive | ESA Gaia Archive — Data Release 3 |
| Distance in light-years | 11.912 ly | ± 0.007 ly | Derived from Gaia DR3 parallax (3.6522 ± 0.0023 pc) (J2016.0) | definitive | ESA Gaia Archive — Data Release 3 |
| Apparent visual magnitude (V) | 3.5 mag | ± 0.01 mag | Johnson UBV photoelectric photometry | definitive | Hipparcos New Reduction Catalog |
| Stellar mass | 0.783 M☉ | ± 0.012 M☉ | CHARA interferometric radius (0.793 ± 0.004 R☉) + asteroseismology | definitive | SIMBAD Astronomical Database (CDS) |
| Metallicity [Fe/H] | -0.52 dex | ± 0.03 dex | High-resolution optical spectroscopy | definitive | SIMBAD Astronomical Database (CDS) |
J2000 Equatorial Sky Chart & Culmination Altitude
The chart below plots Tau Ceti (HD 10700 Nearby Solar Analog) at RA 01h 44m 04.08s, Dec -15° 56′ 14.9″ within Cetus, alongside peak meridian transit altitudes for 40°N and 30°S observers. Use the RA/Dec Coordinate Converter to compute exact culmination altitude for your latitude.
Astrophysical Context & Structure
Tau Ceti (HD 10700, 52 Ceti) is the closest solitary G-type main-sequence star to the Solar System, located 3.652 ± 0.002 parsecs (11.912 light-years) away in the southern constellation Cetus. With a spectral class of G8 V, a mass of 0.783 solar masses, a radius of 0.793 solar radii, and a luminosity of 52% solar, Tau Ceti has long been an iconic benchmark for nearby Sun-like stars—selected alongside Epsilon Eridani by Frank Drake in 1960 for Project Ozma, the first radio search for extraterrestrial intelligence.
Chemically, Tau Ceti is an old, metal-poor disk star (age ~8–10 billion years) containing only ~30% of the Sun's iron-to-hydrogen abundance ([Fe/H] = −0.52 dex), though its magnesium-to-silicon ratio is higher than solar. Submillimeter observations with the James Clerk Maxwell Telescope and ALMA have resolved a broad, cold Kuiper-belt-like debris disk extending from ~10 AU to 55 AU around Tau Ceti that contains roughly ten times more cometary and asteroidal dust than our own Solar System's Kuiper Belt.
Extreme-precision radial-velocity monitoring with HARPS and HIRES has identified four candidate super-Earth/mini-Neptune signals with orbital periods of 20.0, 49.4, 162.9, and 636 days (minimum masses 1.75 to 3.9 Earth masses), with the outer two candidates (Tau Ceti e and f) straddling the inner and outer edges of the star's habitable zone.
Practical Visual Observing Guide
- Shining at visual magnitude 3.50 in a relatively sparse region of Cetus (about 10° northeast of Diphda / β Ceti), Tau Ceti is easily visible to the naked eye from suburban and rural skies.
- When you look at Tau Ceti with the unaided eye, you are seeing a solitary yellow-orange dwarf only slightly cooler (5,344 K vs 5,772 K) and smaller than our own Sun from a distance of just 11.9 light-years.
- Its large proper motion (1.92 arcseconds per year northwest) is typical of old, high-velocity disk stars passing through the solar neighborhood.
Catalog Cross-Identifications & Aliases
Common Aliases: τ Ceti · HD 10700 · HIP 8102 · 52 Ceti
| Catalog Authority | Identifier |
|---|---|
| GAIADR3 | 2452378776434276992 |
| HIP | HIP 8102 |
| HD | HD 10700 |
| SIMBAD | * tau Cet |
| WIKIDATA | Q10542 |
Related Objects, Comparisons & Guides
Proxima Centauri (Nearest Star to Sun)
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Sirius (Alpha Canis Majoris Binary)
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51 Pegasi b (Dimidium First Hot Jupiter)
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TRAPPIST-1 e (Temperate Terrestrial World)
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Trigonometric Parallax, Parsecs & Gaia DR3
How trigonometric parallax (d_pc = 1 / p_arcsec), the distance modulus equation, Hipparcos, and Gaia DR3 microarcsecond astrometry measure cosmic distances.
Stellar Spectral Classification (OBAFGKM)
Reference guide to Morgan-Keenan (MK) stellar classification (O B A F G K M), luminosity classes (I–V, WD), color index (B-V), and the H-R diagram.
Proper Motion, Radial Velocity & Redshift
How astronomers combine tangential proper motion (mas/yr), Doppler radial velocity (km/s), and cosmological redshift (z) to reconstruct 3D space motion.
Bright, Multiple & Variable Stars Catalog
Cross-reference catalog of solar-neighborhood and navigation stars across Bayer, Henry Draper (HD), Hipparcos (HIP), WDS, and Gaia DR3 designations.
Confirmed Exoplanets & Host Systems Catalog
Curated NASA Exoplanet Archive reference catalog of benchmark exoplanets: Proxima Centauri b, TRAPPIST-1 e, 51 Pegasi b, HD 209458 b, K2-18 b, and WASP-39 b.
Scientific Sources & Dataset Provenance
- ESA Gaia Archive — Data Release 3 (DR3 (2022-06-13)): Gaia Collaboration, Vallenari, A., et al. 2023, A&A, 674, A1 (Gaia Data Release 3) — European Space Agency / Gaia DPAC
- Hipparcos New Reduction Catalog (2007 New Reduction): van Leeuwen, F. 2007, A&A, 474, 653 (Validation of the new Hipparcos reduction) — ESA / van Leeuwen (2007)
- NASA Exoplanet Archive (2026-10-01 snapshot): Akeson, R. L., et al. 2013, PASP, 125, 989; NASA Exoplanet Archive (IPAC/Caltech) — NASA Exoplanet Science Institute (NExScI / Caltech / IPAC)