Beta Aquarii
 Location of β Aquarii (circled) |
|
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Aquarius |
| Right ascension | 21h 31m 33.53171s |
| Declination | –05° 34′ 16.2320″ |
| Apparent magnitude (V) | 2.87 |
| Characteristics | |
| Spectral type | G0 Ib |
| U−B color index | +0.58 |
| B−V color index | +0.84 |
| Astrometry | |
| Radial velocity (Rv) | 6.5 km/s |
| Proper motion (μ) |
RA: +18.77 mas/yr Dec.: –8.21 mas/yr |
| Parallax (π) | 6.07 ± 0.22mas |
| Distance | 540 ± 20 ly (165 ± 6 pc) |
| Absolute magnitude (MV) | –3.34 |
| Details | |
| Mass | 6.0–6.5 M☉ |
| Radius | 50 R☉ |
| Luminosity | 2,300 L☉ |
| Surface gravity (log g) | 2.05 cgs |
| Temperature | 5,700 K |
| Metallicity [Fe/H] | –0.03 dex |
| Rotational velocity (v sin i) | 6.3 ± 1.3 km/s |
| Age | 60 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Beta Aquarii (β Aquarii, abbreviated Beta Aqr, β Aqr), also named Sadalsuud, is a double star in the constellation of Aquarius. Based upon parallax measurements, it is located at a distance of about 540 light-years (160 parsecs) from the Sun.
β Aquarii (Latinised to Beta Aquarii) is the star's Bayer designation.
It bore the traditional name Sadalsuud, from an Arabic expression سعد السعود sa‘d al-su‘ūd, the "luck of lucks". Other spellings that were sometimes encountered were Sad es Saud, Sadalsund, and Saad el Sund. In the catalogue of stars in the Calendarium of Al Achsasi Al Mouakket, this star was designated Nir Saad al Saaoud, which was translated into Latin as Lucida Fortunæ Fortunarum (rather identic with R.H. Allen), meaning the brightest of luck of lucks. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name Sadalsuud for this star on 21 August 2016 and it is now so entered in the IAU Catalog of Star Names.
In Chinese, 虚宿 (Xū Sù), meaning Emptiness (asterism), refers to an asterism consisting of Beta Aquarii and Alpha Equulei. Consequently, Beta Aquarii itself is known as 虛宿一 (Xū Sù yī, English: the First Star of Emptiness.)
Sadalsuud is found in Hindu texts as Kalpeny and, in the context of the ancient Indian system of astronomy, Jyotisha Veda, is located in the 23rd Nakshatra Shravishthā, a lunar mansion which is ruled by Eight vasus - the "deities of earthly abundance" . On the Euphrates, Sadalsuud was known as Kakkab Nammax, the Star of Mighty Destiny; that may have given origin to the title of the manzil, as well as to the astrologers' name for it — Fortuna Fortunarum.
...
Wikipedia