Astronomy:Pi Aquilae
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Aquila[1] |
| Right ascension | 19h 48m 42.059s[2] |
| Declination | +11° 48′ 57.22″[2] |
| Apparent magnitude (V) | 5.85 (6.47 + 6.75)[3] |
| Characteristics | |
| Spectral type | G8 III: + A1 V[3][4] |
| Astrometry | |
| π Aql A | |
| Radial velocity (Rv) | +12.6[4] km/s |
| Proper motion (μ) | RA: +17.838[2] mas/yr Dec.: −9.891[2] mas/yr |
| Parallax (π) | 6.3883 ± 0.0342[2] mas |
| Distance | 511 ± 3 ly (156.5 ± 0.8 pc) |
| Absolute magnitude (MV) | −0.22[1] |
| Details | |
| π Aql A | |
| Luminosity | 108[1] L☉ |
| Temperature | 5,937+1,255 −569[5] K |
| π Aql B | |
| Radius | 10.9+0.5−0.9[6] R☉ |
| Luminosity | 74.3±0.9[6] L☉ |
| Surface gravity (log g) | 4.5[6] cgs |
| Temperature | 5,128+226−105[6] K |
| Other designations | |
| A: HD 187259 | |
| B: HD 187260 | |
| Database references | |
| SIMBAD | data |
| A | |
| B | |
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
- ↑ 1.0 1.1 1.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 2.0 2.1 2.2 2.3 2.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 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, Bibcode: 2008MNRAS.389..869E.
- ↑ 4.0 4.1 4.2 4.3 "Composite Spectra - Part Three - Pi-Aquilae", Journal for the History of Astronomy 10 (4): 433, December 1989, doi:10.1007/BF02715077, Bibcode: 1989JApA...10..433G.
- ↑ Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 6.0 6.1 6.2 6.3 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ "* pi. Aql". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+pi.+Aql.
External links
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