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]
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| 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 mas[1] |
| Distance | 510 ± 40 ly (160 ± 10 pc) |
| Absolute magnitude (MV) | −0.22[4] |
| Details | |
| Luminosity | 108[4] L☉ |
| Other designations | |
| A: HD 187259 | |
| B: HD 187260 | |
| Database references | |
| SIMBAD | data |
| A | |
| B | |
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
edit- ^ a b c d e f 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.
- ^ 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.
- ^ 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
- ^ a b 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.
- ^ "* pi. Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-20.