Epoch J2000 Equinox J2000
|Right ascension||19h 55m 18.8s|
|Declination||+06° 24′ 24″|
|Apparent magnitude (V)||3.71/11.4|
|Spectral type||G8 IVvar|
|U−B color index||0.48|
|B−V color index||0.86|
|R−I color index||0.49|
|Radial velocity (Rv)||-40.3 km/s|
|Proper motion (μ)||RA: 46.35 mas/yr
Dec.: -481.32 mas/yr
|Parallax (π)||72.95 ± 0.83 mas|
|Distance||44.7 ± 0.5 ly
(13.7 ± 0.2 pc)
|Mass||1.26 ± 0.18 M☉|
|Radius||3.28 ± 0.15 R☉|
|Luminosity||6.0 ± 0.3 L☉|
|Surface gravity (log g)||3.60 cgs|
|Metallicity [Fe/H]||–0.30 dex|
|Rotational velocity (v sin i)||0.9 km/s|
Bright Star Catalogue (5th rev. ed.)
Beta Aquilae (β Aql, β Aquilae) is a star in the constellation Aquila. It has the traditional name Alshain from the Perso-Arabic term الشاهين aš-šāhīn "the (peregrine) falcon", perhaps by folk etymology from the Persian šāhīn tarāzū (or possibly šāhīn tara zed; see γ Aquilae), the Persian name for the asterism α, β and γ Aquilae.
In Chinese, 河鼓 (Hé Gŭ), meaning River Drum, refers to an asterism consisting of β Aquilae, Altair and γ Aql. Consequently, β Aquilae itself is known as 河鼓一 (Hé Gŭ yī, English: the First Star of River Drum.)
In the catalogue of stars in the Calendarium of Al Achsasi al Mouakket, this star was designated Unuk al Ghyrab (عنق ألغراب - únuq al-ghuraab), which was translated into Latin as Collum Corvi, meaning the crow's neck.
Beta Aquilae has magnitude 3.71 and is of spectral class G8IV. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. It is approximately 44.7 light years from Earth. It has a 12th magnitude optical companion, β Aquilae B, which is 13 arcseconds away in the sky.
Alshain as the name
USS Alshain (AKA-55) was a United States navy ship.
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