24 Aquarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 21h 39m 31.53468s[1] |
| Declination | −00° 03′ 04.1095″[1] |
| Apparent magnitude (V) | 6.66[2] (7.08 + 15.11 + 7.90[3]) |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | F5.5V + M5V + F8V[3] |
| U−B color index | +0.04[3] +0.005 (Aa)[3] +1.13 (Ab)[3] +0.15 (B)[3] |
| B−V color index | +0.514[3] +0.459 (Aa)[3] +1.701 (Ab)[3] +0.642 (B)[3] |
| Astrometry | |
| Radial velocity (Rv) | −15.86±0.06[2] km/s |
| Proper motion (μ) | RA: +215.367[1] mas/yr Dec.: +17.077[1] mas/yr |
| Parallax (π) | 22.63±0.25 mas[3] |
| Distance | 144 ± 2 ly (44.2 ± 0.5 pc) |
| Absolute magnitude (MV) | 3.45[2] |
| Orbit[3] | |
| Primary | 24 Aqr A |
| Name | 24 Aqr B |
| Period (P) | 48.98±0.07 yr |
| Semi-major axis (a) | 0.4250±0.0005″ |
| Eccentricity (e) | 0.8610±0.0002 |
| Inclination (i) | 55.00±0.04° |
| Longitude of the node (Ω) | 140.26±0.05° |
| Periastron epoch (T) | 2020.799±0.003 |
| Argument of periastron (ω) (secondary) | 293.95±0.07° |
| Orbit[4] | |
| Primary | 24 Aqr Aa |
| Name | 24 Aqr Ab |
| Period (P) | 5.883933(15) days |
| Semi-major axis (a) | 0.0706±0.0019[3] AU |
| Eccentricity (e) | 0.071±0.006 |
| Inclination (i) | 55.8±2.9[3]° |
| Periastron epoch (T) | 46,988.58±0.08 MJD |
| Argument of periastron (ω) (secondary) | 286±5° |
| Semi-amplitude (K1) (primary) | 14.60±0.09 km/s |
| Details[3] | |
| 24 Aqr Aa | |
| Mass | 1.12±0.06 M☉ |
| Radius | 1.23±0.04 R☉ |
| Luminosity | 2.4±0.1 L☉ |
| Surface gravity (log g) | 4.40±0.06 cgs |
| Temperature | 6,483±80 K |
| Metallicity [Fe/H] | –0.09[5] dex |
| Age | 3.612 Gyr |
| 24 Aqr Ab | |
| Mass | 0.24±0.05 M☉ |
| Radius | 0.28±0.04 R☉ |
| Surface gravity (log g) | 4.80±0.06 cgs |
| Age | 3.612 Gyr |
| 24 Aqr B | |
| Mass | 1.06±0.05 M☉ |
| Radius | 1.02±0.04 R☉ |
| Luminosity | 1.33±0.05 L☉ |
| Surface gravity (log g) | 4.47±0.06 cgs |
| Temperature | 6,150±80 K |
| Age | 3.612 Gyr |
| Other designations | |
| 24 Aqr, BD−00°4245, HD 206058, HIP 106942, SAO 145566, WDS J21395-0003, LTT 8626 | |
| Database references | |
| SIMBAD | data |
24 Aquarii is a triple star[6] system in the equatorial constellation of Aquarius. 24 Aquarii is the Flamsteed designation. The apparent magnitude of this system is 6.66,[2] 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. Based on a dynamical parallax measurement,[3] the system is located at a distance of 144 light-years (44 parsecs). The system is moving closer to the Earth with a heliocentric radial velocity of −16 km/s.[2]
The components A and B make up a visual binary wiith an orbital period of 48.98 years and a high eccentricity of 0.8610.[6] Both are main sequence stars with spectral types of F5.5V and F8V, respectively. Component A is itself a single-lined spectroscopic binary with a period of 5.8839 days and an eccentricity of 0.071±0.006,[4] being orbited by a faint red dwarf with a spectral type of M5V.[3]
References
- ^ a b c d Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d e Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b c d e f g h i j k l m n o p q r Abushattal, Ahmad A.; Al-Wardat, Mashhoor A.; Horch, Elliott P.; Georgakarakos, Nikolaos; Al-Ameryeen, Hatem A.; Abu-Alrob, Enas M.; Hussein, Abdallah M. (January 2024), "The 24 Aqr triple system: A closer look at its unique high-eccentricity hierarchical architecture", Advances in Space Research, 73 (1): 1170–1184, arXiv:2512.23645, Bibcode:2024AdSpR..73.1170A, doi:10.1016/j.asr.2023.10.044, ISSN 0273-1177.
- ^ a b Griffin, R. F.; et al. (June 1996), "Spectroscopic binary orbits from photoelectric radial velocities. Paper 128: 24 Aquarii", The Observatory, 116: 162–175, Bibcode:1996Obs...116..162G.
- ^ Casagrande, L.; et al. (June 2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy and Astrophysics, 530: A138, arXiv:1103.4651, Bibcode:2011A&A...530A.138C, doi:10.1051/0004-6361/201016276, S2CID 56118016.
- ^ a b Branham, Richard L. Jr. (March 2005), "Calculating the Apparent Orbit of a Double Star", The Astrophysical Journal, 622 (1): 613–61, Bibcode:2005ApJ...622..613B, doi:10.1086/427870.