96 Aquarii
Star in the constellation Aquarius
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96 Aquarii is a multiple star[3] system in the zodiac constellation of Aquarius. The designation is from the star catalogue of English astronomer John Flamsteed, first published in 1712. It is faintly visible to the naked eye with an apparent visual magnitude of 5.56.[2] The estimated distance to this system, based upon an annual parallax shift of 29.27 mas, is around 111 light years.[1] The system has a relatively large proper motion[3] and it is moving closer to the Sun with a radial velocity of −7 km/s.[5]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 23h 19m 23.97754s[1] |
| Declination | −05° 07′ 27.6485″[1] |
| Apparent magnitude (V) | 5.56[2] + 10.92[3] |
| Characteristics | |
| Spectral type | F4 V Fe−0.4[4] + M3 V[3] |
| B−V color index | 0.40/1.37[3] |
| Astrometry | |
| Radial velocity (Rv) | −7.17±0.35[5] km/s |
| Proper motion (μ) | RA: +201.39[1] mas/yr Dec.: −18.13[1] mas/yr |
| Parallax (π) | 29.27±0.67 mas[1] |
| Distance | 111 ± 3 ly (34.2 ± 0.8 pc) |
| Absolute magnitude (MV) | 2.89[2] |
| Orbit[3] | |
| Primary | Aab |
| Period (P) | 21.2371±0.0020 d |
| Eccentricity (e) | 0.60 |
| Periastron epoch (T) | 22478.56 ± 0.38 JHD |
| Argument of periastron (ω) (secondary) | 314±7° |
| Semi-amplitude (K1) (primary) | 42.7±3.6 km/s |
| Orbit[3] | |
| Name | Bab |
| Period (P) | 659.9±3.6 d |
| Eccentricity (e) | 0.60 |
| Periastron epoch (T) | 51429.1 ± 7.2 JHD |
| Argument of periastron (ω) (secondary) | 59.3±10.6° |
| Semi-amplitude (K1) (primary) | 8.49±1.05 km/s |
| Details[6] | |
| 96 Aqr Aa | |
| Mass | 1.32 M☉ |
| Luminosity | 5.82[2] L☉ |
| Surface gravity (log g) | 4.21±0.14 cgs |
| Temperature | 6,813±232 K |
| Metallicity [Fe/H] | −0.12±0.08[2] dex |
| Age | 949 Myr |
| 96 Aqr Ba | |
| Mass | 0.40 M☉ |
| Other designations | |
| 96 Aqr, BD−05°5966, HD 219877, HIP 115142, HR 8868, SAO 146639[7] | |
| Database references | |
| SIMBAD | data |
The visible components, A and B, have an angular separation of 9.8 arc seconds and share a common proper motion. Their presumed orbital period is estimated as 4,400 years. Component A was first identified as a single-lined spectroscopic binary by Adams et al. (1924) at the Mount Wilson Observatory. It has an orbital period of 21.2 days with an eccentricity of 0.60.[3] The Aab pair have an angular separation of 6 mas and a combined stellar classification of F4 V Fe−0.4,[4] matching an F-type main-sequence star with a mild underabundance of iron. Magnitude 10.92 component B is likewise a single-lined spectroscopic binary, having an orbital period of 659.9 days and an eccentricity of 0.70. The separation of Bab is 45 mas,[3] and their spectrum matches a red dwarf class of M3 V.[3]