| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 21h 04m 04.72438s[1] |
| Declination | −05° 49′ 23.0347″[1] |
| Apparent magnitude (V) | 5.67 (5.88 + 7.55)[2] |
| Characteristics | |
| Spectral type | K0/1 III + A3 V[3] or G4 II + A3+ + (A4)[4] |
| Astrometry | |
| Radial velocity (Rv) | +1.1±0.3[5] km/s |
| Proper motion (μ) | RA: +20.35[1] mas/yr Dec.: -6.67[1] mas/yr |
| Parallax (π) | 6.50 ± 0.88 mas[1] |
| Distance | approx. 500 ly (approx. 150 pc) |
| Absolute magnitude (MV) | 0.1 + 1.4 + 1.5[4] |
| Details | |
| 12 Aqr Aa/Ab | |
| Mass | 2.6/2.0[4] M☉ |
| Temperature | 5,012/8,511[4] K |
| 12 Aqr B | |
| Mass | 1.9[4] M☉ |
| Temperature | 8,318[4] K |
| Other designations | |
| 12 Aqr A: HD 200497, HR 8059, SAO 145065 | |
| 12 Aqr B: HD 200496, HR 8058, SAO 145064 | |
| Database references | |
| SIMBAD | 12 Aqr |
| 12 Aqr A | |
| 12 Aqr B | |
12 Aquarii is a triple star[2] system in the zodiac constellation of Aquarius. 12 Aquarii is the Flamsteed designation. It is visible to the naked eye as a dim star with an apparent visual magnitude of 5.67.[2] Parallax measurements by Hipparcos puts it at a distance of some 500 light-years, or 150 parsecs away.[1] The system is moving further from the Earth with a heliocentric radial velocity of +1.1 km/s.[5]
The magnitude 5.88 primary,[2] component A, is itself a binary star with a separation of 0.05″–0.07″ and an orbital period of around 18.5 yr. The brighter member of this duo is a G-type bright giant with a stellar classification of G4 II and 2.6 times the mass of the Sun. Its companion is an early A-type star with double the mass of the Sun.[4] The tertiary component B is magnitude 7.55[2] A-type main-sequence star[3] at a separation of 2.44″ from the primary.[2]
HIP was invoked but never defined (see the help page).Eggleton2008 was invoked but never defined (see the help page).Houk1999 was invoked but never defined (see the help page).Parsons2004 was invoked but never defined (see the help page).Gontcharov was invoked but never defined (see the help page).