Delta Ceti

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Template:Short description

Delta Ceti
Template:Location mark
Location of δ Ceti (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cetus
Right ascension Template:RA[1]
Declination Template:DEC[1]
Apparent magnitude (V) +4.06[2]
Characteristics
Spectral type B2 IV[3]
U−B Template:Engvar −0.88[2]
B−V Template:Engvar −0.21[2]
Variable type β Cep[3]
Astrometry
Radial velocity (Rv)Script error: No such module "val".[4] km/s
Proper motion (μ) RA: Script error: No such module "val".[1] mas/yr
Dec.: Script error: No such module "val".[1] mas/yr
Parallax (π)5.02±0.15 mas[1]
DistanceTemplate:Rnd ± Template:Rnd ly
(Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)−2.41[5]
Details
MassScript error: No such module "val".[3] Template:Solar mass
RadiusScript error: No such module "val".[3] Template:Solar radius
Luminosity4,000[3] Template:Solar luminosity
Surface gravity (log g)Script error: No such module "val".[3] cgs
TemperatureScript error: No such module "val".[3] K
Metallicity [Fe/H]−0.24[5] dex
Rotational velocity (v sin i)Script error: No such module "val".[3] km/s
Age7−18[6] Myr
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
Template:Odlist
Database references
SIMBADdata

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Delta Ceti, Latinized from δ Ceti, is a single,[7] blue-white hued star in the equatorial constellation of Cetus. The star's apparent visual magnitude of +4.06[2] means it is near to the cusp of the faintest third of the stars that are visible the ideally-placed naked eye. It is Script error: No such module "val". north of the celestial equator compared to the celestial north pole's Script error: No such module "val".. The star is positioned about Script error: No such module "val". WNW of the spiral galaxy M77, but which at apparent magnitude 9.6 needs magnification to be made out and has an apparent size of only Script error: No such module "val". by Script error: No such module "val"..

Based upon an annual parallax shift of Script error: No such module "val". as seen from Earth,[1] it is around Script error: No such module "val". from the Sun. Motion relative to our system's trajectory includes a highly parting vector: with a net radial velocity of about Script error: No such module "val"..[4] It moves minutely across the celestial sphere – yet just over four times more in right ascension than in declination.

File:DeltaCetLightCurve.png
A light curve for Delta Ceti, plotted from TESS data[8]

This is a Beta Cephei variable[3] with a stellar classification of B2 IV.[3] It varies in brightness with a period of 0.16114 days.[6] Unlike most stars of its type, it does not display multiple periods of luminosity variation or multiple variations of its spectral line profiles.[9] The star is about 7−18[6] million years and has a low projected rotational velocity of around Script error: No such module "val".,[3] suggesting it is either rotating slowly or is being viewed from nearly pole on.[6] It has 8.4[3] times the mass of the Sun and 4.6[3] times the Sun's radius. The star is radiating around 4,000[3] times the Sun's luminosity from its photosphere at an effective temperature of roughly Script error: No such module "val".[3]

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".[10]

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.)[11]

In Chinese, Script error: No such module "Lang". (Script error: No such module "Lang".), 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, the Chinese name for δ Ceti itself is Script error: No such module "Lang". (Script error: No such module "Lang"., Template:Langx.)[12]

References

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  1. a b c d e f Script error: No such module "Citation/CS1".Vizier catalog entry
  2. a b c d Script error: No such module "Citation/CS1".
  3. a b c d e f g h i j k l m n o Script error: No such module "citation/CS1".
  4. a b Script error: No such module "citation/CS1".
  5. a b Script error: No such module "citation/CS1".
  6. a b c d Script error: No such module "citation/CS1".
  7. Script error: No such module "Citation/CS1".
  8. Script error: No such module "citation/CS1".
  9. Script error: No such module "citation/CS1".
  10. Star Name - R.H. Allen p.160
  11. 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
  12. Template:In lang AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 11 日 Template:Webarchive

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External links

Template:Stars of Cetus