HD 180555 is a binary star in the equatorial constellation of Aquila. It consists of a two stars, orbiting with an orbital period of 8.95 years and an eccentricity of 0.43. A third component lies at an angular separation of 8.32″, but it is unrelated to the system.[3]

HD 180555
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 19h 16m 26.78744s[1]
Declination +14° 32′ 40.6234″[1]
Apparent magnitude (V) 5.67[2] (5.68 + 9.58)[3]
Characteristics
Spectral type B9.5V[4] + G0IV[3]
U−B color index −0.12[2]
B−V color index −0.03[2]
Astrometry
Radial velocity (Rv)−19.3[5] km/s
Proper motion (μ) RA: +8.09[1] mas/yr
Dec.: +1.03[1] mas/yr
Parallax (π)7.96 ± 0.60 mas[1]
Distance410 ± 30 ly
(126 ± 9 pc)
Orbit[6]
Period (P)13.673 ± 0.069 yr
Semi-major axis (a)0.0583 ± 0.0014″
Eccentricity (e)0.022 ± 0.010
Inclination (i)131.3 ± 3.7°
Longitude of the node (Ω)242.3 ± 4.5°
Periastron epoch (T)B 2008.572 ± 1.101
Argument of periastron (ω)
(secondary)
262.7 ± 28.7°
Details
HD 180555 A
Rotational velocity (v sin i)158[7] km/s
Other designations
BD+14° 3852, HD 180555, HIP 94720, HR 7307, SAO 104668.
Database references
SIMBADdata

References

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  1. ^ a b c d e van 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. S2CID 18759600.
  2. ^ a b c Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M
  3. ^ a b c Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976
  4. ^ Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819
  5. ^ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick (eds.), "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode:1967IAUS...30...57E
  6. ^ "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 1 August 2017. Retrieved 21 May 2017.
  7. ^ Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224, S2CID 18475298
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