Alpha Gruis

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Alpha Gruis
Observation data
Epoch J2000
Constellation
(pronunciation)
Grus
Right ascension 22h 08m 14.0s
Declination -46° 57′ 39.5″
Apparent magnitude (V) +1.73
Characteristics
Spectral type B7 IV
U-B color index -0.46
B-V color index -0.13
Variable type None
Astrometry
Radial velocity (Rv) +10.9 km/s
Proper motion (μ) RA: 127.6 mas/yr
Dec.: -147.9 mas/yr
Parallax (π) 32.16 ± 0.82 mas
Distance 101 ± 3 ly
(31.1 ± 0.8 pc)
Absolute magnitude (MV) -0.74
Details
Mass ? M
Radius 3.6 R
Luminosity 380 L
Temperature 13,500 K
Metallicity ?
Rotation ~236 km/s.
Age ? years
Other designations
Al Na'ir, Gl 848.2, HR 8425, CD -47°14063, HD 209952, GCTP 5339.00, SAO 230992, FK5 829, HIP 109268.

Alpha Gruis (α Gru / α Gruis) is the brighest star in the constellation Grus. It also has the traditional name Alnair (sometimes Al Na'ir or Al Nair, from the Arabic al-nayyir meaning "the bright (one)"). Confusingly, Alnair is also given as the proper name for Zeta Centauri by a navigator in middle of 20th century.[1]

[edit] References

  1. ^ P. Kunitzsch, T. Smart, 2006, A Dictionary of Modern Star Names: A Short Guide to 254 Star Names and Their Derivations, Sky Pub. Corp.