Beta Ophiuchi

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Beta Ophiuchi

Observation data
Epoch J2000.0 (ICRS)
Constellation
(pronunciation)		 Ophiuchus
Right ascension 17h 43m 28.353s
Declination +04° 34′ 02.29″
Apparent magnitude (V) 2.75 to 2.77
Characteristics
Spectral type K2III
U-B color index 1.24
B-V color index 1.16
Variable type K-type giant[1],[2]
Astrometry
Radial velocity (Rv) -12 km/s
Proper motion (μ) RA: -40.67 mas/yr
Dec.: 158.80 mas/yr
Parallax (π) 39.78 ± 0.75 mas
Distance 82 ± 2 ly
(25.1 ± 0.5 pc)
Absolute magnitude (MV) 0.75 to 0.77
Other designations
β Oph, β Ophiuchi, 60 Oph, 60 Ophiuchi, Cebalrai, Cheleb, Kelb Alrai, HR 6603, BD +04°3489, HD 161096, SAO 122671, FK5 665, HIP 86742.
Data sources:
Hipparcos Catalogue,
Bright Star Catalogue (5th rev. ed.),
GCVS (4.2),[1],[2]

Beta Ophiuchi (β Oph / β Ophiuchi) is a K-type giant star in the constellation Ophiuchus. It also has the traditional names Cebalrai (Arabic: "shepherd dog"), Cheleb, or Kelb Alrai, or sometimes just Alrai. Like some other K-type giants, β Ophiuchi has been found to vary very slightly (0.02 magnitudes) in brightness.[1],[2]

[edit] References

  1. ^ a b c K Giants in 47 Tucanae: Detection of a New Class of Variable Stars, Peter D. Edmonds and Roland L. Gilliland, Astrophysical Journal Letters 464 (June 1996), pp. L157–L160
  2. ^ a b c The Radial Velocity Variability of the K Giant beta Ophiuchi. II. Long-Period Variations, Artie P. Hatzes and William D. Cochran, Astrophysical Journal 468 (September 1996), pp. 391–397