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Lambda Ceti is the λ star in the Cetus constellation, just above Menkar (α Cet) in the pentangle. |
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| Observation data Epoch J2000 Equinox J2000 |
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|---|---|
| Constellation | Cetus |
| Right ascension | 02h 59m 42.9018s[1] |
| Declination | 08° 54′ 26.513″[1] |
| Apparent magnitude (V) | 4.6767[2] |
| Characteristics | |
| Spectral type | B6III [1] |
| U−B color index | -0.45 |
| B−V color index | -0.12 |
| Astrometry | |
| Radial velocity (Rv) | 10.2[1] km/s |
| Proper motion (μ) | RA: 9.22[1] mas/yr Dec.: -14.92[1] mas/yr |
| Parallax (π) | 5.66 ± 0.24[2] mas |
| Distance | 580 ± 20 ly (177 ± 7 pc) |
| Absolute magnitude (MV) | -1.56 |
| Details | |
| Mass | ~4.6[3] M☉ |
| Radius | 5.4 [3] R☉ |
| Luminosity | 920 [3] L☉ |
| Temperature | 13,400 [3] K |
| Metallicity | ? Fe/H |
| Rotational velocity (v sin i) | 150[4] km/s |
| Age | 1.0-1.25×108[3] years |
| Other designations | |
| Database references | |
| SIMBAD | data |
| NStED | data |
Lambda Ceti (λ Cet, λ Ceti) is Class B star of fifth-magnitude star 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".[5].
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.[6] Consequently, λ Ceti itself is known as 天囷三 (Tiān Qūn sān, English: the Third Star of Circular Celestial Granary.)[7]
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Lambda Ceti is a blue giant star with stellar classification B6III. With a mass between 4.5-4.8M☉ and an estimated radius that is 5.4R☉, the star radiates a bolometric luminosity of about 920 L☉.[3] 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.[2] 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.[2]
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