Xi2 Ceti

Xi2 Ceti
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cetus
Right ascension 02h 28m 09.55706s
Declination +08° 27 36.2168
Apparent magnitude (V) +4.279
Characteristics
Spectral type B9.5III or A0III-
U−B color index −0.137
B−V color index −0.053±0.003
Astrometry
Radial velocity (Rv)11.90±1.3 km/s
Proper motion (μ) RA: 23.707±0.844 mas/yr
Dec.: −4.787±0.778 mas/yr
Parallax (π)16.5681±0.4608 mas
Distance197 ± 5 ly
(60 ± 2 pc)
Absolute magnitude (MV)+0.45
Details
Mass2.45 M
Radius2.60±0.17 R
Luminosity80.13 L
Surface gravity (log g)4.00±0.25 cgs
Temperature10,630±400 K
Metallicity [Fe/H]−0.43±0.04 dex
Rotational velocity (v sin i)55 km/s
Age127 Myr
Other designations
ξ2 Cet, 73 Ceti, BD+07°388, HD 15318, HIP 11484, HR 718, SAO 110543
Database references
SIMBADdata

Xi2 Ceti, Latinized from ξ2 Ceti, is a star located in the equatorial constellation of Cetus. It is visible to the naked eye with an apparent visual magnitude of +4.3. This star is located at a distance of approximately 197 light years from the Sun based on parallax, and is drifting further away with a radial velocity of 12 km/s. It made its closest approach some 2.7 million years ago at a distance of around 128 light-years.

Xi2 Ceti is a spectrophotometric standard star. It displays a stellar classification of B9.5III, which suggests it has exhausted its core hydrogen, evolved away from the main sequence, and expanded to become a giant star, although still only 127 million years old. It has 2.45 times the mass and 2.6 times the radius of the Sun.

In Chinese, 天囷 (Tiān Qūn), meaning Circular Celestial Granary, refers to an asterism consisting of α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, δ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, the Chinese name for Xi2 Ceti itself is "the Sixth Star of Circular Celestial Granary", Tiān Qūn Liù.