Astronomy:Pi Aquilae

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Short description: Star in the constellation Aquila
Pi Aquilae
Diagram showing star positions and boundaries of the Aquila constellation and its surroundings
Cercle rouge 100%.svg
Location of π Aquilae (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquila
Right ascension  19h 48m 42.05765s[1]
Declination +11° 48′ 57.2177″[1]
Apparent magnitude (V) 5.85 (6.47/6.75)[2]
Characteristics
Spectral type G8 III: + A1 V[2][3]
Astrometry
Radial velocity (Rv)+12.6[3] km/s
Proper motion (μ) RA: +16.16[1] mas/yr
Dec.: –10.60[1] mas/yr
Parallax (π)6.34 ± 0.52[1] mas
Distance510 ± 40 ly
(160 ± 10 pc)
Absolute magnitude (MV)−0.22[4]
Details
Luminosity108[4] L
Other designations
π Aql, 52 Aquilae, BD+11 3994, HIP 97473, HR 7544, SAO 105282[5]
A: HD 187259
B: HD 187260
Database references
SIMBADdata
A
B

Pi Aquilae, Latinised from π Aquilae, is the Bayer designation for a binary star[2] system in the equatorial constellation of Aquila, about 3° to the north of the bright star Altair.[3] The apparent visual magnitude of the system is 5.85,[2] making it faintly visible to the naked eye from dark suburban skies. Based upon an annual parallax shift of 6.34 mas, the distance to this system is roughly 510 light-years (160 parsecs).[1]

The binary nature of this system was first discovered by William Herschel in 1785.[3] The primary component of is a magnitude 6.47[2] giant star with a stellar classification of G8 III:.[2] A companion star at an angular separation of 1.437 arcseconds is an A-type main-sequence star with a classification of A1 V.[2] It is slightly fainter, with an apparent magnitude of 6.75.[2]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  3. 3.0 3.1 3.2 3.3 Griffin, R. (December 1989), "Composite Spectra - Part Three - Pi-Aquilae", Journal for the History of Astronomy 10 (4): 433, doi:10.1007/BF02715077, Bibcode1989JApA...10..433G 
  4. 4.0 4.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  5. "* pi. Aql". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+pi.+Aql. 

External links