Astronomy:Psi Aquilae

From HandWiki
Short description: Star in the constellation Aquila
Psi Aquilae
Aquila IAU.svg
Red circle.svg
Location of ψ Aquilae (circled)
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
Distance1,150 ± 30 ly
(354 ± 9 pc)
Absolute magnitude (MV)−1.17[6]
Details
Radius3.7[7] R
Luminosity341[6] L
Temperature10,814±232[8] K
Rotational velocity (v sin i)20[9] km/s
Age~247[10] Myr
Other designations
ψ Aql, 48 Aquilae, BD+12° 4059, HD 186547, HIP 97139, HR 7511, SAO 105199[2]
Database references
SIMBADdata

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. 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. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 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. 3.0 3.1 Cowley, A. (November 1972), "Spectral classification of the bright B8 stars", Astronomical Journal 77: 750–755, doi:10.1086/111348, Bibcode1972AJ.....77..750C. 
  4. 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, Bibcode1963ApJ...137..530C. 
  5. 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, Bibcode1967IAUS...30...57E. 
  6. 6.0 6.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  7. 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, Bibcode2001A&A...367..521P. 
  8. 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, Bibcode2005A&A...444..941P. 
  9. 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, Bibcode2002ApJ...573..359A. 
  10. Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode2012AstL...38..694G. 
  11. "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 

External links