Alpha Aquarii

Alpha Aquarii
Location of α Aquarii (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Aquarius
Right ascension 22h 05m 47.03555s[1]
Declination −00° 19′ 11.4634″[1]
Apparent magnitude (V) 2.942[2]
Characteristics
Evolutionary stage Yellow supergiant
Spectral type G2 Ib[3]
U−B color index +0.699[2]
B−V color index +0.971[2]
R−I color index +0.49[2]
Astrometry
Radial velocity (Rv)7.5[4] km/s
Proper motion (μ) RA: +18.59 mas/yr[1]
Dec.: −10.45 mas/yr[1]
Parallax (π)4.9451 ± 0.4296 mas[1]
Distance690.8+37.8
−56.1 ly
(211.9+11.6
−17.2 pc)[5]
Absolute magnitude (MV)−3.882[6]
Details
Mass6.31[7] M☉
Radius83[7] R☉
Luminosity3,917[7] L☉
Surface gravity (log g)1.4[7] cgs
Temperature5,190±50[8] K
Metallicity [Fe/H]+0.17[6] dex
Rotational velocity (v sin i)6.7±1.5[9] km/s
Age53[3] Myr
Other designations
El Melik, Rucbah, Saad el Melik, Sadalmelek, Sadalmelik, Sadlamulk, α Aqr, Alpha Aquarii, Alpha Aqr, 34 Aquarii, 34 Aqr, BD−01 4246, FK5 827, Gaia DR2 2680356911815074432, HD 209750, HIP 109074, HR 8414, SAO 145862, WDS 22058-0019, 2MASS J22054703-0019114[10][11][12][13]
Database references
SIMBADdata

Alpha Aquarii, officially named Sadalmelik (/ˌsædəlˈmɛlɪk/),[14] is a single yellow supergiant star in the constellation of Aquarius. The apparent visual magnitude of 2.94[2] makes this the second-brightest star in Aquarius. Based upon parallax measurements made by the Gaia spacecraft, it is located at a distance of roughly 690 light-years (210 parsecs) from the Sun.[5] It is drifting further away from the Sun with a radial velocity of 7.5 km/s.[4]

It forms the primary or 'A' component of a double star designated WDS J22058-0019; the secondary or 'B' component is UCAC2 31789179.[15] However, the pair is only an optical binary, with UCAC2 31789179 being a background star.[15]

  1. ^ a b c d Cite error: The named reference DR3 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference saoc8_59 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference mnras402_2_1369 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference scfs was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference b-j was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference aaa480_1_91 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Ayres2023 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Usenko_et_al_2017 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference apj627_1_L53 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference bsc1 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference sb0 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference wds was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference allen was invoked but never defined (see the help page).
  14. ^ "Naming Stars". IAU.org. Retrieved 25 February 2018.
  15. ^ a b "UCAC2 31789179 -- Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2018-02-25