4 Aquarii
| Observation data EpochJ2000EquinoxJ2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 20h51m25.74827s[1] |
| Declination | −05° 37′ 35.8719″[1] |
| Apparent magnitude(V) | 5.99[2](6.40 + 7.43)[3] |
| Characteristics | |
| Spectral type | F7 IV + F6: V:[4] |
| B−Vcolor index | 0.464±0.003[2] |
| Astrometry | |
| Radial velocity(Rv) | −21.50[5]km/s |
| Proper motion(μ) | RA:95.47[1]mas/yr Dec.:1.78[1]mas/yr |
| Parallax(π) | 16.47 ± 0.59mas[1] |
| Distance | 198 ± 7ly (61 ± 2pc) |
| Absolute magnitude(MV) | 2.15[6] |
| Orbit[7] | |
| Period(P) | 200.7±1.1yr |
| Semi-major axis(a) | 0.816±0.006″ |
| Eccentricity(e) | 0.535+0.006 −0.005 |
| Inclination(i) | 64.06+0.26 −0.27° |
| Longitude of the node(Ω) | 174.31+0.38 −0.39° |
| Periastronepoch(T) | B1,896.8+0.39 −0.40 |
| Argument of periastron(ω) (secondary) | 45.9±1.2° |
| Details[6] | |
| 4 Aqr A | |
| Mass | 1.618±0.004[7]M☉ |
| Luminosity | 11.0L☉ |
| Surface gravity(logg) | 3.79cgs |
| Temperature | 6,440K |
| Metallicity[Fe/H] | 0.18[8]dex |
| Rotational velocity(vsini) | 34.6 km/s |
| Age | 1.60[8]Gyr |
| 4 Aqr B | |
| Mass | 1.331±0.003[7]M☉ |
| Other designations | |
| Database references | |
| SIMBAD | 4 Aqr |
| 4 Aqr A | |
| 4 Aqr B | |
4 Aquarii(abbreviated4 Aqr) is abinary starsystem in the constellationAquarius,[9]located approximately 198light yearsaway from the Sun.[1]4 Aquariiis theFlamsteed designation.It is visible to the naked eye as a dim, yellow-white hued star with a combinedapparent visual magnitudeof 5.99.[2]The system is moving closer to the Earth with a heliocentricradial velocityof −21.5 km/s.[5]
This is a visual binary with anorbital periodof 200.7 years and aneccentricityof 0.535.[7]The magnitude 6.40[3]primary, designated component A, is anF-typesubgiant starwith astellar classificationof F7 IV,[4]suggesting that it has exhausted the hydrogen at its core andevolvedoff the main sequence.[7]It has a dynamically-measured mass 1.6[7]times that of the Sun and is radiating 11 times theSun's luminosityfrom itsphotosphereat aneffective temperatureof 6,440 K.[6]The magnitude 7.43[3]secondary, component B, is a suspectedF-type main-sequence starof class F6 V.[4]The pair are an estimated 1.6 billion years old.[8]
References[edit]
- ^abcdefvan Leeuwen, F. (2007)."Validation of the new Hipparcos reduction".Astronomy and Astrophysics.474(2): 653–664.arXiv:0708.1752.Bibcode:2007A&A...474..653V.doi:10.1051/0004-6361:20078357.S2CID18759600.
- ^abcAnderson, 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.S2CID119257644.
- ^abcMason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog",The Astronomical Journal,122(6): 3466,Bibcode:2001AJ....122.3466M,doi:10.1086/323920
- ^abcCorbally, C. J.; Garrison, R. F. (August 1980). "New spectral classifications on the MK system for visual double stars".Publications of the Astronomical Society of the Pacific.92:493–496.Bibcode:1980PASP...92..493C.doi:10.1086/130700.S2CID121017167.
- ^abGontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system".Astronomy Letters.32(11): 759–771.arXiv:1606.08053.Bibcode:2006AstL...32..759G.doi:10.1134/S1063773706110065.S2CID119231169.
- ^abcLuck, R. Earle (January 2017)."Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants".The Astronomical Journal.153(1): 19.arXiv:1611.02897.Bibcode:2017AJ....153...21L.doi:10.3847/1538-3881/153/1/21.S2CID119511744.21.
- ^abcdefMendez, Rene A.; et al. (November 2017)."Orbits for 18 Visual Binaries and Two Double-line Spectroscopic Binaries Observed with HRCAM on the CTIO SOAR 4 m Telescope, Using a New Bayesian Orbit Code Based on Markov Chain Monte Carlo".The Astronomical Journal.154(5): 22.arXiv:1709.06582.Bibcode:2017AJ....154..187M.doi:10.3847/1538-3881/aa8d6f.S2CID55695873.187.
- ^abcCasagrande, 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.S2CID56118016.
- ^ab"* 4 Aqr".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved23 October2014.
