Delta Velorum

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Delta Velorum A/B
Observation data
Epoch J2000
Constellation
(pronunciation)		 Vela
Right ascension 08h 44m 42.2s
Declination −54° 42′ 30″
Apparent magnitude (V) 1.95 (2.03/5.1)
Characteristics
Spectral type A1 V/G0 V
U-B color index 0.06
B-V color index 0.04
Variable type Eclipsing binary
Astrometry
Radial velocity (Rv) +2.2 km/s
Proper motion (μ) RA: 28.78 mas/yr
Dec.: −104.14 mas/yr
Parallax (π) 40.90 ± 0.38 mas
Distance 79.7 ± 0.7 ly
(24.4 ± 0.2 pc)
Absolute magnitude (MV) −0.01 (0.05/3.51)
Other designations
Gl 321.3 A/B, HR 3485, CD -54°1788, HD 74956, GCTP 2098.00, SAO 236232, GC 12069, CCDM 08448-5442, HIP 42913.
Database references
SIMBAD data

Delta Velorum (δ Vel / δ Velorum) is a star system in the constellation Vela. It is approximately 79.7 light years from Earth. It is sometimes given the name Koo She, Chinese for 'Bow and Arrows', along with ω Velorum and stars in Canis Major.[1]

The system is composed of two binary stars. The brightest of the four stars, δ Velorum A, is a white A-type main sequence dwarf with an apparent magnitude of +2.02. Its binary companion, δ Velorum B, has a magnitude of +5.1 and is separated from the A component by 2.6 arcseconds.

The second binary system is 69 arcseconds away. It is composed of the 11th magnitude δ Velorum C and the 13th magnitude δ Velorum D, which are 6 arcseconds apart.

This star was recently discovered to be variable by the Galileo spaceprobe at Jupiter. [1] It fluctuates by about 30% every 45 days. Curiously, being one of the brighter stars in the sky, this had not been noticed previously.

Because of precession, δ Velorum will be the South Polar Star around 9000 AD.

[edit] Etymology

The Chinese name Koo She 弧矢 (Mandarin húshǐ) "Bow and Arrow", originally assigned for some stars among Canis Major, Puppis, and Vela, was introduced by Robson for this star.

[edit] References

  1. ^ Allen, Richard Hinckley (1963). Star Names: Their Lore and Meaning, Revised edition, New York: Dover Publications, p. 73. ISBN 0486210790. 
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