Delta Ceti
| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Cetus |
| Right ascension | 02h 39m 28.956s[1] |
| Declination | +00° 19′ 42.63″[1] |
| Apparent magnitude (V) | +4.08 |
| Characteristics | |
| Spectral type | B2 IV[2] |
| Variable type | β Cep[2] |
| Astrometry | |
| Proper motion (μ) | RA: 12.85 ± 0.17[1] mas/yr Dec.: –2.94 ± 0.11[1] mas/yr |
| Parallax (π) | 5.02 ± 0.15[1] mas |
| Distance | 650 ± 20 ly (199 ± 6 pc) |
| Details | |
| Mass | 8.4 ± 0.7[2] M☉ |
| Radius | 4.6 ± 0.8[2] R☉ |
| Luminosity | 4,000[2] L☉ |
| Surface gravity (log g) | 4.05 ± 0.20[2] cgs |
| Temperature | 21,900 ± 1,000[2] K |
| Rotational velocity (v sin i) | 7 ± 4[2] km/s |
| Other designations | |
Delta Ceti (δ Ceti, δ Cet) is a Class B2, fourth-magnitude star in the constellation Cetus.
Contents
Properties
Delta Ceti is positioned very near the celestial equator and is located about 0.74 degrees WNW of the spiral galaxy M77. Delta Ceti is a blue giant star located about 660 light-years from Earth.
It is a Beta Cephei variable.[2]
Name
This star, along with α Cet (Menkar), λ Cet (Menkar), γ Cet (Kaffaljidhma), μ Cet, ξ1 Cet and ξ2 Cet were Al Kaff al Jidhmah, "the Part of a Hand".[3]
According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al Kaff al Jidhmah were the title for five stars :γ Cet as Kaffaljidhma, ξ1 Cet as Al Kaff al Jidhmah I, ξ2 Cet as Al Kaff al Jidhmah II, δ Cet as Al Kaff al Jidhmah III and μ Cet as Al Kaff al Jidhmah IV (exclude α Cet and λ Cet)[4]
In Chinese, 天囷 (Tiān Qūn), meaning Circular Celestial Granary, refers to an asterism consisting of δ Ceti, α Ceti, κ1 Ceti, λ Ceti, μ Ceti, ξ1 Ceti, ξ2 Ceti, ν Ceti, γ Ceti, 75 Ceti, 70 Ceti, 63 Ceti and 66 Ceti. Consequently, δ Ceti itself is known as 天囷九 (Tiān Qūn jiǔ, English: the Ninth Star of Circular Celestial Granary.)[5]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Lua error in package.lua at line 80: module 'strict' not found.Vizier catalog entry
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Star Name - R.H. Allen p.160
- ↑ Jack W. Rhoads - Technical Memorandum 33-507-A Reduced Star Catalog Containing 537 Named Stars, Jet Propulsion Laboratory, California Institute of Technology; November 15, 1971
- ↑ (Chinese) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日
External links
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