Alpha Crateris

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Alpha Crateris
Diagram showing star positions and boundaries of the Crater constellation and its surroundings
Cercle rouge 100%.svg

Location of α Crateris (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Crater
Right ascension 10h 59m 46.4647s[1]
Declination −18° 17′ 55.62″[1]
Apparent magnitude (V) 4.07[1]
Spectral type K1 III
Variable type None
Radial velocity (Rv) 46.8 km/s
Proper motion (μ) RA: −462.38 mas/yr
Dec.: 129.11 mas/yr
Parallax (π) 18.71 ± 1.03 mas
Distance 174 ± 10 ly
(53 ± 3 pc)
Absolute magnitude (MV) 5.17
Mass 2.5[2] M
Radius 6.5[citation needed] R
Luminosity 25[2] L
Surface gravity (log g) 3.1[2] cgs
Temperature 4,620[3] K
Other designations
7 Crt, NLTT 25942, LTT 4040, HD 95272, BD-17° 3273, HIP 53740, HR 4287, FK5 1283, SAO 156375.
Database references

Alpha Crateris (α Crt, α Crateris) is a star in the constellation Crater. It has the traditional name Alkes, from the Arabic الكاس alkās or الكأس alka's "the cup".

In the catalogue of stars in the Calendarium of Al Achsasi al Mouakket, this star was designated Aoul al Batjna (أول ألبجن awwil albajna), which was translated into Latin as Prima Crateris, meaning the first cup.[4]

In Chinese, 翼宿 (Yì Sù), meaning Wings (asterism), refers to an asterism consisting of α Crateris, γ Crateris, ζ Crateris, λ Crateris, ν Hydrae, η Crateris, δ Crateris, ι Crateris, κ Crateris, ε Crateris, HD 95808, HD 93833, θ Crateris, HD 102574, HD 100219, β Crateris, HD 99922, HD 100307, HD 96819, χ1 Hydrae, HD 102620 and HD 103462.[5] Consequently, α Crateris itself is known as 翼宿一 (Yì Sù yī, English: the First Star of Wings.).[6]


Alpha Crateris belongs to the spectral class K1, has apparent magnitude 4.07, and is 174 light years from Earth.


USS Alkes (AK-110) was a United States Navy Crater class cargo ship named after the star.


  1. ^ a b c "Alpha Crateris". SIMBAD Query. Retrieved 2009-09-14. 
  2. ^ a b c Edvardsson, B. (January 1988), "Spectroscopic surface gravities and chemical compositions for 8 nearby single sub-giants", Astronomy and Astrophysics 190 (1-2): 148–166, Bibcode:1988A&A...190..148E 
  3. ^ Melo, C. H. F. et al. (August 2005), "On the nature of lithium-rich giant stars. Constraints from beryllium abundances", Astronomy and Astrophysics 439 (1): 227–235, arXiv:astro-ph/0504133, Bibcode:2005A&A...439..227M, doi:10.1051/0004-6361:20041805 
  4. ^ Knobel, E. B. (June 1895). "Al Achsasi Al Mouakket, on a catalogue of stars in the Calendarium of Mohammad Al Achsasi Al Mouakket". Monthly Notices of the Royal Astronomical Society 55: 429. Bibcode:1895MNRAS..55..429K. doi:10.1093/mnras/55.8.429. 
  5. ^ (Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
  6. ^ (Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.

External links[edit]

Coordinates: Sky map 10h 59m 46.4647s, −18° 17′ 55.62″