Eta Lyrae
star
Eta Lyrae, a name Latinized from η Lyrae, is a likely binary star system in the northern constellation of Lyra. It has the traditional name Aladfar and is faintly visible to the naked eye with an apparent visual magnitude of 4.43. The system is located at a distance of approximately 1,390 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −8 km/s.
Nomenclature
η Lyrae (Latinised to Eta Lyrae) is the binary star's Bayer designation. Its designation as the A component of a double star, and of its two constituents as the Aa and Ab components, derives from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).
'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 (of the swooping eagle)", a name it shares with Mu Lyrae (though the latter is typically spelled Alathfar). The Working Group on Star Names (WGSN) has approved the name Aladfar for the Aa component of the system (the primary component of Eta Lyrae).
Properties
The suspected radial velocity variations of this star in 1938 led to it being incorrectly classified as a Beta Cephei-type star, although there was some early disagreement about the variation. In 1951, J. A. Pearce and R. M. Petrie also noted that the star appeared to have a variable radial velocity.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 23, 2026. The linked authority identifier is Q1570903. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1938 and 1951.
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This entry incorporates text from “Eta Lyrae” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.