Eta Lyrae

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Eta Lyrae
Observation data
Epoch J2000      Equinox J2000
Constellation Lyra
Right ascension 19h 13m 45.48832s[1]
Declination +39° 08′ 45.4801″[1]
Apparent magnitude (V) 4.40[2]
Spectral type B2.5IV[2]
Radial velocity (Rv) -8.1 ± 0.9[1] km/s
Proper motion (μ) RA: −0.60[1] mas/yr
Dec.: −1.26[1] mas/yr
Parallax (π) 2.35 ± 0.13[1] mas
Distance 1,390 ± 80 ly
(430 ± 20 pc)
Surface gravity (log g) 3.38[3] cgs
Temperature 17,360[3] K
Metallicity [Fe/H] -0.01[3] dex
Rotational velocity (v sin i) 10[4] km/s
Other designations
20 Lyr, HD 180163, HIP 94481, HR 7298, SAO 68010, BD+38° 3490[2]
Database references

Eta Lyrae (η Lyr, η Lyrae) is a star in the constellation Lyra. It has the traditional name Aladfar, from the Arabic الأظفر al-’uz̧fur "the talons (of the swooping eagle)", a name it shares with Mu Lyrae (though the latter is typically spelled Alathfar in English).[citation needed]

Eta Lyrae belongs to spectral class B2.5IV and has apparent magnitude of +4.40.[2] It is approximately 1,390 light years from Earth.[1]


  1. ^ a b c d e f g van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d "* eta Lyr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 25 July 2015. 
  3. ^ a b c Cenarro, A. J.; Peletier, R. F.; Sanchez-Blazquez, P.; Selam, S. O.; Toloba, E.; Cardiel, N.; Falcon-Barroso, J.; Gorgas, J.; Jimenez-Vicente, J.; Vazdekis, A. (2007). "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters". Monthly Notices of the Royal Astronomical Society. 374 (2): 664. doi:10.1111/j.1365-2966.2006.11196.x. 
  4. ^ Prugniel, Ph.; Vauglin, I.; Koleva, M. (2011). "The atmospheric parameters and spectral interpolator for the MILES stars". Astronomy & Astrophysics. 531: A165. doi:10.1051/0004-6361/201116769.