Eta Lyrae
Eta Lyrae is the primary or 'A' component of a triple star system in the constellation of Lyra. It is approximately 1,390 light-years from the Sun.
The secondary or 'B' component is the star BD +38 3491. Eta Lyrae is itself a spectroscopic binary with components designated Aa and Ab.Nomenclature
η Lyrae is the binary star's Bayer designation. Its designation as the A component of a triple star system, and of its two constituents as the Aa and Ab components, derives from the convention used by the Washington Multiplicity Catalog for multiple star systems, and adopted by the International Astronomical Union.
'BD +38 3491' is the 'B' component's designation in the Bonner Durchmusterung astrometric star catalogue.
Eta Lyrae bore the traditional name Aladfar, from the Arabic الأظفر al-ʼuẓfur "the talons ", a name it shares with Mu Lyrae. The Working Group on Star Names has approved the name Aladfar for the Aa component of the triple star system.Properties
Eta Lyrae belongs to spectral class B2.5IV and has apparent magnitude of +4.40. It is a single-lined spectroscopic binary, with a very small radial velocity variation of. The orbital period is.
