Epsilon Delphini

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Epsilon Delphini
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Delphinus
Right ascension 20h 33m 12.8s
Declination +11° 18′ 12″
Apparent magnitude (V) +4.03
Characteristics
Spectral type B6III
U−B color index −0.47
B−V color index −0.13
Variable type suspected
Astrometry
Radial velocity (Rv) −19 km/s
Proper motion (μ) RA: +10.75 mas/yr
Dec.: −28.54 mas/yr
Parallax (π) 9.09 ± 0.81 mas
Distance 358 ly
(110 pc)
Absolute magnitude (MV) −1.18
Details
Radius 4.6[1] R
Temperature 13,614 ± 15[1] K
Other designations
Deneb Dulfim, Deneb el Delphinus, 2 Delphini, HR 7852, HD 195810, SAO 106230, HIP 101421, BD +10 4321, FK5: 768, NSV 13137, TD1 26903

Epsilon Delphini (ε Del, ε Delphini) is a blue-white giant star approximately 358 light-years away in the constellation Delphinus. It has the traditional name Deneb Dulfim (occasianally Deneb or Al Dhanab al Dulfim), from the Arabic ذنب الدلفين ðanab ad-dulfīn "tail of the dolphin."

The term ðanab ad-dulfīn or Dzaneb al Delphin was appeared in the catalogue of stars in the Calendarium of Al Achsasi Al Mouakket, which was translated into Latin as Cauda Delphini, meaning the dolphin's tail.[2]

In Chinese, 敗瓜 (Bài Guā), meaning Rotten Gourd, refers to an asterism consisting of ε Delphini, η Delphini, θ Delphini, ι Delphini and κ Delphini.[3] Consequently, ε Delphini itself is known as 敗瓜一 (Bài Guā yī, English: the First Star of Rotten Gourd.).[4] From this Chinese name, the name Pae Chaou was appeared [5]

The star is slightly variable, occasionally brightening to magnitude 3.95.

See also[edit]

References[edit]

  1. ^ a b Underhill, A. B. et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society 189: 601–605, Bibcode:1979MNRAS.189..601U 
  2. ^ 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. 
  3. ^ (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.
  4. ^ (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.
  5. ^ Star Name - R.H.Allen p.201