Alpha Doradus, Latinized from α Doradus, is the brightest star in the southern constellation of Dorado. The distance to this system, as measured using the parallax method, is about 169 light-years (52 parsecs).
This is a binary star system with an overall apparent visual magnitude that varies between 3.26 and 3.30, making this one of the brightest binary stars. The system consists of a subgiant star of spectral type B revolving around a giant star with spectral type A in an eccentric orbit with a period of about 12 years. The orbital separation varies from 2 astronomical units at periastron to 17.5 astronomical units at apastron. The primary, α Doradus A, is a chemically peculiar star whose atmosphere displays an abnormally high abundance of silicon, making this an Si star.
Alpha Doradus has an optical companion, CCDM J04340-5503C, located 77 arcseconds away along a position angle of 94°. It has no physical relation to the other two stars.
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- ^ a b c HIP 21281, record for component 2, Hipparcos catalogue; CDS ID I/239.
- ^ a b alf Dor, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars Archived 2017-06-20 at the Wayback Machine, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line September 3, 2008.
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- ^ a b "Entry 04340-5503", Sixth Catalog of Orbits of Visual Binary Stars, United States Naval Observatory, archived from the original on 2005-04-24, retrieved 2008-09-03
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- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
- ^ "alf Dor". The International Variable Star Index. AAVSO. Retrieved 2 July 2022.
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- ^ "Entry 04340-5503, discoverer code HJ3668, components AB-C", The Washington Double Star Catalog, United States Naval Observatory, archived from the original on 2008-04-12, retrieved 2008-09-03