24 Aquarii

24 Aquarii
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension 21h 39m 31.53468s
Declination −00° 03 04.1095
Apparent magnitude (V) 6.66
Characteristics
Spectral type F7 III OR F7V + ? + F9V
B−V color index +0.52
Astrometry
Radial velocity (Rv)−15.86±0.06 km/s
Proper motion (μ) RA: +215.367 mas/yr
Dec.: +17.077 mas/yr
Parallax (π)25.0839±0.6277 mas
Distance130 ± 3 ly
(39.9 ± 1.0 pc)
Absolute magnitude (MV)3.45
Orbit
Period (P)48.65 yr
Semi-major axis (a)0.448″
Eccentricity (e)0.868
Inclination (i)58.0°
Longitude of the node (Ω)139.3°
Periastron epoch (T)1971.55
Argument of periastron (ω)
(secondary)
293.0°
Details
24 Aqr Aa
Mass1.25 M
Radius1.42+0.05
−0.08
 R
Luminosity2.864±0.080 L
Temperature6,231 K
Metallicity [Fe/H]–0.09 dex
Age3.5 Gyr
Other designations
24 Aqr, BD−00°4245, HD 206058, HIP 106942, SAO 145566, WDS J21395-0003, LTT 8626
Database references
SIMBADdata

24 Aquarii is a triple star system in the equatorial constellation of Aquarius. 24 Aquarii is the Flamsteed designation. The apparent magnitude of this system is 6.66, which, according to the Bortle Dark-Sky Scale, means it is a faint star that is just visible to the naked eye from dark, rural skies. It has an annual parallax shift of 25.08 mas, which is equivalent to a distance of 130 light-years (40 parsecs) from Earth. The system is moving closer to the Earth with a heliocentric radial velocity of −16 km/s.

The calculated orbit of the visual binary has a period of 48.65 years and a large eccentricity of 0.868. The primary, component A, is itself a single-lined spectroscopic binary with a period of 5.8839 days and an eccentricity of 0.071±0.006. One study gives the system a stellar classification of F7 III, suggesting it contains an evolved giant star. Other classifications give classes matching F-type main-sequence stars for components Aa and B.