Pi Aquilae

Pi Aquilae

Location of π Aquilae (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Aquila
Right ascension	19^h 48^m 42.05765^s[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 mas[1]
Distance	510 ± 40 ly (160 ± 10 pc)
Absolute magnitude (MV)	−0.22[4]
Details
Luminosity	108[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
SIMBAD	data
	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. van Leeuwen, F. (November 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. 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.
3. 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
4. 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.
5. "* pi. Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-20.

External links

• HR 7544
• Image Pi Aquilae
• CCDM 19487+1149