Delta Aquilae
binary system in the constellation Aquila
Delta Aquilae, also named Guqi, is a binary star system in the equatorial constellation of Aquila. Its Bayer designation is Latinized from δ Aquilae, and abbreviated Delta Aql or δ Aql. This system has an apparent visual magnitude of 3.4 and, based upon parallax measurements, is located at a distance of about 50.6 light-years (15.5 parsecs) from Earth. It is drifting closer with a radial velocity of −30 km/s. The system is predicted to come to within 25.4 ly (7.8 pc) of the Sun in around 335,000 years.
Properties
The binary nature of this system was first reported by H. L. Alden at Yale Observatory in 1936. It is an astrometric binary where the two components orbit each other with a period of 3.422 years and an eccentricity (ovalness) of about 0.36. This is a type of binary star system where the presence of the secondary component is revealed by its gravitational perturbation of the primary. The individual components have not been resolved with a telescope.
The primary member, designated component Aa, is an aging subgiant star with a stellar classification of F0 IV, where the luminosity class of IV indicates it is in the process of exhausting the supply of hydrogen at its core and evolving into a giant star.
“Delta Aquilae” enters the record as binary system in the constellation Aquila. Crown Archives preserves that source wording while asking what Delta, Aquilae and binary can confirm, complicate or overturn.
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This entry incorporates text from “Delta Aquilae” 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.