Pi Aquilae

Pi Aquilae is a binary star[3] system in the equatorial constellation of Aquila, about 3° to the north of the bright star Altair.[4] Its name is a Bayer designation that is Latinised from π Aquilae, and abbreviated Pi Aql or π Aql. The apparent visual magnitude of the system is 5.85,[3] making it faintly visible to the naked eye from dark suburban skies. Based upon an annual parallax shift of 6.39 mas, the distance to this system is approximately 511 light-years (157 parsecs).[2]

The binary nature of this system was first discovered by William Herschel in 1785.[4] The primary component is a magnitude 6.47[3] giant star with a stellar classification of G8 III:.[3] A companion star at an angular separation of 1.437 arcseconds is an A-type main-sequence star with a classification of A1 V.[3] It is slightly fainter, with an apparent magnitude of 6.75.[3]

References

  1. ^ a b c 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.
  2. ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. ^ a b c d e f g h 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. ^ a b c d Griffin, R. (December 1989), "Composite Spectra - Part Three - Pi-Aquilae", Journal for the History of Astronomy, 10 (4): 433, Bibcode:1989JApA...10..433G, doi:10.1007/BF02715077, S2CID 124841724.
  5. ^ 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.
  6. ^ 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.
  7. ^ "* pi. Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-20.