Alpha Doradus (Alpha Dor, α Doradus, α Dor) 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.
- HIP 21281, record for component 1, Hipparcos catalogue; CDS ID I/239.
- HR 1465, database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID V/50. Accessed on line September 3, 2008.
- HIP 21281, record for component 2, Hipparcos catalogue; CDS ID I/239.
- alf Dor, database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line September 3, 2008.
- V* alf Dor -- Variable Star, database entry, SIMBAD. Accessed on line September 3, 2008.
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- "Entry 04340-5503", Sixth Catalog of Orbits of Visual Binary Stars (United States Naval Observatory), retrieved 2008-09-03
- North, P. (June 1998), "Do SI stars undergo any rotational braking?", Astronomy and Astrophysics 334: 181–187, arXiv:astro-ph/9802286, Bibcode:1998A&A...334..181N
- Kaler, James B., Alpha Dor, retrieved 2012-03-04
- Heintz, W. D. (April 1984), "Note on the orbit of alpha Doradus", The Observatory 104: 88–89, Bibcode:1984Obs...104...88H
- "Entry 04340-5503, discoverer code HJ3668, components AB-C", The Washington Double Star Catalog (United States Naval Observatory), retrieved 2008-09-03