HR 7484
| Observation data EpochJ2000EquinoxJ2000 | |
|---|---|
| Constellation | Cygnus |
| Right ascension | 19h38m41.18316s[2] |
| Declination | +54° 58′ 25.6420″[2] |
| Apparent magnitude(V) | 5.889±0.015,[3]6.37[4] |
| Characteristics | |
| Spectral type | F6V[5](F5 V + F5 V)[3] |
| B−Vcolor index | 0.482±0.004[5] |
| Variable type | Algol[4] |
| Astrometry | |
| Radial velocity(Rv) | −13.9±0.2[5]km/s |
| Proper motion(μ) | RA:+34.885[2]mas/yr Dec.:+162.839[2]mas/yr |
| Parallax(π) | 24.7090 ± 0.0422mas[2] |
| Distance | 132.0 ± 0.2ly (40.47 ± 0.07pc) |
| Absolute magnitude(MV) | 2.83[5] |
| Orbit[3] | |
| Period(P) | 7.64075217±0.00000051d[6] |
| Semi-major axis(a) | 22.6950AU |
| Eccentricity(e) | 0.5378±0.0003 |
| Inclination(i) | 87.0±1.0° |
| Argument of periastron(ω) (secondary) | 0.860±0.001° |
| Semi-amplitude(K1) (primary) | 88.02±0.05km/s |
| Semi-amplitude(K2) (secondary) | 89.97±0.10km/s |
| Details[3] | |
| V1143 Cyg A | |
| Mass | 1.356±0.003M☉ |
| Radius | 1.339±0.023R☉ |
| Luminosity | 2.83±0.2[7]L☉ |
| Surface gravity(logg) | 4.317±0.015cgs |
| Temperature | 6,450±100K |
| Metallicity[Fe/H] | 0.08dex |
| Rotational velocity(vsini) | 18±3[7]km/s |
| V1143 Cyg B | |
| Mass | 1.328±0.002M☉ |
| Radius | 1.316±0.023R☉ |
| Luminosity | 2.65±0.2[7]L☉ |
| Surface gravity(logg) | 4.323±0.015cgs |
| Temperature | 6,400±100K |
| Rotational velocity(vsini) | 28±3[7]km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
HR 7484(V1143 Cyg) is abinary starsystem in the northernconstellationofCygnus.It is dimly visible to the naked eye under good viewing conditions, having anapparent visual magnitudeof 5.89.[3]Based upon an annualparallax shiftof 24.71,[2]it is located 132light yearsaway. The system is moving closer with a heliocentricradial velocityof −14 km/s.[5]
Observational history
[edit]Radial velocity measurements taken at theDominion Astrophysical ObservatoryinVictoria, British ColumbiaCanada in 1919 led to the determination byWilliam Edmund Harperthat HR 7484 is a double-linedspectroscopic binary.[9]The next year he published an orbit with a period of 7.6383 days as compared to the modern value of 7.64075217 days.[10]
Physical characteristics
[edit]HR 7484 is a detachedeclipsing binary,which means theorbital planeis aligned close to the line-of-sight from the Earth, causing the components toeclipsetwice per orbit.[11]The system is undergoingapsidal motion,with a rate greater than that predicted bygeneral relativity.[11]Both components are ordinaryF-type main-sequence starswith similar physical properties.[3]The star normally has an apparent magnitude of 5.89, but every 7.64 days (7 days, 15 hours, and 22 minutes) its brightness decreases to magnitude 6.37, approximately two thirds as bright. Five days and 17 hours after each primary eclipse, there is asecondary eclipsewhen the brightness drops to magnitude 6.06, about 85% of the normal brightness. Each eclipse lasts for 220 minutes.[4]Both eclipses arepartial.[7]
References
[edit]- ^"MAST: Barbara A. Mikulski Archive for Space Telescopes".Space Telescope Science Institute.Retrieved8 December2021.
- ^abcdefBrown, A. G. A.;et al. (Gaia collaboration) (August 2018)."GaiaData 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 sourceatVizieR.
- ^abcdefGraczyk, Dariusz; et al. (March 2017)."The Surface Brightness-color Relations Based on Eclipsing Binary Stars: Toward Precision Better than 1% in Angular Diameter Predictions".The Astrophysical Journal.837(1): 19.arXiv:1611.09976.Bibcode:2017ApJ...837....7G.doi:10.3847/1538-4357/aa5d56.S2CID119004886.7.
- ^abcSamus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)".VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S.1.Bibcode:2009yCat....102025S.
- ^abcdeAnderson, 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.
- ^Gimenez, A.; Margrave, T. E. (2005)."Relativistic apsidal motion in the eclipsing binary systems V1143 Cygni and EK Cephei".Astronomical Journal.90(2): 358–363.arXiv:astro-ph/0411788.Bibcode:1985AJ.....90..358G.doi:10.1086/113740.
- ^abcdeAnderson, J.; Garcia, J.; Gimenez, A.; Nordstrom, B. (1987). "Absolute dimensions of eclipsing binaries. X - V1143 Cygni".Astronomy & Astrophysics.174:107–115.Bibcode:1987A&A...174..107A.
- ^"HD 185912".SIMBAD.Centre de données astronomiques de Strasbourg.Retrieved2018-07-14.
- ^Plaskett, J. S.; et al. (1919). "Fourth list of spectroscopic binaries".Journal of the Royal Astronomical Society of Canada.13:372–378.Bibcode:1919JRASC..13..372P.
- ^Harper, W. E. (1920)."The orbits of the spectroscopic components of Boss 5026".Astrophysical Journal.51:187–189.Bibcode:1920ApJ....51..187H.doi:10.1086/142537.
- ^abDariush, A.; et al. (April 2005). "Photometric Observations and Apsidal Motion Study of V1143 Cyg".Astrophysics and Space Science.296(1–4): 141–144.arXiv:astro-ph/0411788.Bibcode:2005Ap&SS.296..141D.doi:10.1007/s10509-005-4416-0.S2CID119369053.