Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cetus |
Right ascension | 02h 59m 42.89987s[1] |
Declination | 08° 54′ 26.4899″[1] |
Apparent magnitude (V) | 4.71[2] |
Characteristics | |
Spectral type | B6III[3] |
U−B color index | −0.471[2] |
B−V color index | −0.109±0.006[2] |
Astrometry | |
Radial velocity (Rv) | 10.2±2.8[4] km/s |
Proper motion (μ) | RA: 6.01±0.26[1] mas/yr Dec.: −17.70±0.29[1] mas/yr |
Parallax (π) | 5.66 ± 0.24 mas[1] |
Distance | 580 ± 20 ly (177 ± 7 pc) |
Absolute magnitude (MV) | −1.52[2] |
Details | |
Mass | 5.01±0.05[5] M☉ |
Radius | 5.4[6] R☉ |
Luminosity | 652[2] L☉ |
Temperature | 13,940±710[7] K |
Rotational velocity (v sin i) | 131[8] km/s |
Age | 100-125[6] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Lambda Ceti, Latinized from λ Ceti, is a B-type star of fifth-magnitude located in the constellation Cetus. Historically, the star bore the traditional name Menkar, although today that name is more commonly associated with α Ceti.
This star, along with α Cet (Menkar), γ Cet (Kaffaljidhma), δ Cet, μ Cet, ξ1 Cet and ξ2 Cet were Al Kaff al Jidhmah, "the Part of a Hand".[10]
In Chinese, 天囷 (Tiān Qūn), meaning Circular Celestial Granary, refers to an asterism consisting of λ Ceti, α Ceti, κ1 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 λ Ceti itself is 天囷三 (Tiān Qūn sān, English: the Third Star of Circular Celestial Granary.)[11]
Lambda Ceti is a blue giant star with stellar classification B6III. With five[5] times the mass of the Sun and an estimated radius that is 5.4 R☉, the star radiates a bolometric luminosity of about 920 L☉.[6] In 1997 the Hipparcos satellite estimated its parallax at 7.69 ± 0.76 milliarcseconds yielding a distance from Earth of about 130 ± 10 parsecs or 420 ± 40 light years. However recent astrometric calculations by van Leeuwen have placed the distance much farther at about 177 ± 7 pc or 580 ± 20 ly—a revaluation which significantly altered other stellar parameters.[1] Its apparent magnitude has been recently recalibrated at 4.6767 yielding an absolute magnitude of -1.56, almost as bright as its neighbor Alpha Ceti at -1.62.