Deneb

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Deneb
Cygnus constellation map.png
Cygnus, the constellation in which Deneb is locatit.
Observation data
Epoch J2000      Equinox J2000
Constellation Cygnus
Richt ascension 20h 41m 25.9s
Declination +45° 16′ 49″
Apparent magnitude (V) 1.25
Characteristics
Spectral type A2 Ia[1]
U−B colour index −0.24
B−V colour index +0.09
Variable type Alpha Cyg
Astrometry
Radial velocity (Rv) −4.5 km/s
Proper motion (μ) RA: 1.99[2][3] mas/yr
Dec.: 1.95[2][3] mas/yr
Parallax (π) 2.29 ± 0.32[2][3] mas
Distance 802 + 66[4] pc
Absolute magnitude (MV) −8.38[4]
Details
Mass 19 ± 4[4] M
Radius 203 ± 17[4] R
Luminosity 196,000 ± 32,000[4] L
Surface gravity (log g) 1.10 ± 0.05[4]
Temperatur 8,525 ± 75[4] K
Metallicity [Fe/H] -0.25[4] dex
Rotational velocity (v sin i) 20 ± 2[4] km/s
Ither designations
α Cygni, Alpha Cyg, 50 Cyg, Arided, Aridif, Gallina, Arrioph, HR 7924, BD +44°3541, HD 197345, SAO 49941, FK5: 777, HIP 102098.

Deneb (α Cyg, α Cygni, Alpha Cygni) is the brichtest starn in the constellation Cygnus an ane o the vertices o the Simmer Triangle. It is the 19t brichtest starn in the nicht sky, wi an apparent magnitude o 1.25. A blue-white supergiant, Deneb is an aa ane o the maist luminous nearbi starns. However, its exact distance (an hence luminosity) haes been difficult tae calculate, so it is onywhaur atween 54,000 an 196,000 times as luminous as the sun.

Ither names include Arided an Aridif, but these hae fallen oot o uise.

References[eedit | eedit soorce]

  1. Garrison, R. F. (December 1993). "Anchor Points for the MK System of Spectral Classification". Bulletin of the American Astronomical Society 25: 1319. Bibcode:1993AAS...183.1710G. Retrieved 2012-02-04 
  2. 2.0 2.1 2.2 Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; et al. (July 1997). "The Hipparcos Catalogue". Astronomy and Astrophysics 323: L49–L52. Bibcode:1997A&A...323L..49P 
  3. 3.0 3.1 3.2 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 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 Schiller, F.; Przybilla, N. (2008). "Quantitative spectroscopy of Deneb". Astronomy & Astrophysics 479 (3): 849–858. arXiv:0712.0040. Bibcode:2008A&A...479..849S. doi:10.1051/0004-6361:20078590. Earlier data had yielded a luminosity of 54,000L with a radius of 108R