Phi Aquilae
 | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 56m 14.25182s[1] |
| Declination | +11° 25′ 25.3942″[1] |
| Apparent magnitude (V) | +5.28[2] |
| Characteristics | |
| Spectral type | A1 IV[3] |
| U−B color index | –0.02[2] |
| B−V color index | +0.00[2] |
| Astrometry | |
| Radial velocity (Rv) | –27.2[4] km/s |
| Proper motion (μ) | RA: +32.29[1] mas/yr Dec.: +4.44[1] mas/yr |
| Parallax (π) | 14.86 ± 0.25 mas |
| Distance | 219 ± 4 ly (67 ± 1 pc) |
| Orbit[5] | |
| Period (P) | 3.32068 days |
| Eccentricity (e) | 0.025 |
| Periastron epoch (T) | JD 2423210.628 |
| Argument of periastron (ω) (secondary) | 43° |
| Semi-amplitude (K1) (primary) | 37.2 km/s |
| Details | |
| Radius | 1.8–2.5[6] R☉ |
| Surface gravity (log g) | 4.30[7] cgs |
| Temperature | 9,509[7] K |
| Metallicity [Fe/H] | +0.47[7] dex |
| Rotational velocity (v sin i) | 27[8] km/s |
| Other designations | |
Phi Aquilae (φ Aql, φ Aquilae) is the Bayer designation of a binary star[10] system in the equatorial constellation of Aquila. It has an apparent visual magnitude of +5.28[2] and is visible to the naked eye. With an annual parallax shift of 14.86 mas,[1] this star is located at a distance of approximately 219 light-years (67 parsecs) from Earth.
Phi Aquilae is a single-lined spectroscopic binary with an orbital period of 3.32068 days.[5] The primary component is a subgiant star with a stellar classification of A1 IV.[3] The outer atmosphere has an effective temperature of 9,509,[7] giving it a white-hued appearance of an A-type star.[11] The orbiting companion may be the source of the X-ray emission from this system, as stars similar to the primary component do not generally produce detectable levels of X-rays.[12]
References
- ^ a b c d e 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.
- ^ a b c d Oja, T. (April 1983), "UBV photometry of FK4 and FK4 supplement stars", Astronomy and Astrophysics Supplement Series, 52: 131–134, Bibcode:1983A&AS...52..131O.
- ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
- ^ Wilson, Ralph Elmer (1953), General catalogue of stellar radial velocities, Carnegie Institution of Washington, Bibcode:1953QB901.W495......
- ^ a b Lucy, L. B.; Sweeney, M. A. (August 1971), "Spectroscopic binaries with circular orbits", Astronomical Journal, 76: 544–556, Bibcode:1971AJ.....76..544L, doi:10.1086/111159.
- ^ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics, 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
- ^ a b c d Soubiran, C.; Le Campion, J.-F.; Cayrel de Strobel, G.; Caillo, A. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247.
- ^ Royer, F.; Zorec, J.; Gómez, A. E. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224.
- ^ "phi Aql -- Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-21.
- ^ 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.
{{citation}}: CS1 maint: unflagged free DOI (link) - ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, retrieved 2012-01-16
- ^ De Rosa, R. J.; et al. (July 2011), "The Volume-limited A-Star (VAST) survey - I. Companions and the unexpected X-ray detection of B6-A7 stars", Monthly Notices of the Royal Astronomical Society, 415 (1): 854–866, arXiv:1103.4363, Bibcode:2011MNRAS.415..854D, doi:10.1111/j.1365-2966.2011.18765.x.
{{citation}}: CS1 maint: unflagged free DOI (link)
