Astronomy:Psi Aquilae
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 44m 34.19086s[1] |
| Declination | +13° 18′ 10.0063″[1] |
| Apparent magnitude (V) | 6.25[2] |
| Characteristics | |
| Spectral type | B9 III-IV[3] |
| U−B color index | –0.22[4] |
| B−V color index | –0.04[4] |
| Astrometry | |
| Radial velocity (Rv) | –18.3[5] km/s |
| Proper motion (μ) | RA: +0.561[1] mas/yr Dec.: –9.950[1] mas/yr |
| Parallax (π) | 2.8253 ± 0.0752 mas |
| Distance | 1,150 ± 30 ly (354 ± 9 pc) |
| Absolute magnitude (MV) | −1.17[6] |
| Details | |
| Radius | 3.7[7] R☉ |
| Luminosity | 341[6] L☉ |
| Temperature | 10,814±232[8] K |
| Rotational velocity (v sin i) | 20[9] km/s |
| Age | ~247[10] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Psi Aquilae, Latinized as ψ Aquilae, is the Bayer designation for a star in the equatorial constellation of Aquila. It is a faint star with an apparent visual magnitude of 6.25,[2] which, according to the Bortle Dark-Sky Scale, can be seen with the naked eye in dark rural skies. The orbit of the Earth causes an annual parallax shift of 2.83 mas,[1] which indicates a distance of approximately 1,150 light-years (350 parsecs).
The spectrum of Psi Aquilae matches a stellar classification of B9 III-IV,[3] with the luminosity class of III-IV indicating the spectrum lies part way between that of a subgiant and a giant star. The effective temperature of the star's outer atmosphere is 10,814 K,[8] giving it the blue-white hue of a B-type star.[11] It has nearly four[7] times the radius of the Sun and has a projected rotational velocity of 20 km/s.[9]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 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.
- ↑ 2.0 2.1 2.2 "psi Aql -- Star", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Psi+Aquilae, retrieved 2012-07-21.
- ↑ 3.0 3.1 Cowley, A. (November 1972), "Spectral classification of the bright B8 stars", Astronomical Journal 77: 750–755, doi:10.1086/111348, Bibcode: 1972AJ.....77..750C.
- ↑ 4.0 4.1 Crawford, D. L. (February 1963), "U, b, v, and Hβ Photometry for the Bright B8- and B9-TYPE Stars", Astrophysical Journal 137: 530, doi:10.1086/147526, Bibcode: 1963ApJ...137..530C.
- ↑ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick, eds., "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 (University of Toronto: International Astronomical Union) 30: p. 57, Bibcode: 1967IAUS...30...57E.
- ↑ 6.0 6.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 7.0 7.1 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 (2): 521–524, doi:10.1051/0004-6361:20000451, Bibcode: 2001A&A...367..521P.
- ↑ 8.0 8.1 Paunzen, E.; Schnell, A.; Maitzen, H. M. (December 2005), "An empirical temperature calibration for the Δa photometric system. I. The B-type stars", Astronomy and Astrophysics 444 (3): 941–946, doi:10.1051/0004-6361:20053546, Bibcode: 2005A&A...444..941P.
- ↑ 9.0 9.1 Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal 573 (1): 359–365, doi:10.1086/340590, Bibcode: 2002ApJ...573..359A.
- ↑ Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode: 2012AstL...38..694G.
- ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16
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