Alpha Doradus

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title: "Alpha Doradus" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["a-type-giants", "b-type-subgiants", "alpha2-canum-venaticorum-variables", "binary-stars", "dorado", "bayer-objects", "durchmusterung-objects", "henry-draper-catalogue-objects", "hipparcos-objects", "bright-star-catalogue-objects", "lucidae"] description: "Star in the constellation Dorado" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/Alpha_Doradus" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Star in the constellation Dorado ::

| image = | image=Dorado IAU.svg | float=center | width=240 | position=right | mark=Red circle.svg | mark_width=10 | mark_link=α Dor | x%=58.9 | y%=33.9 | caption = Location of α Doradus (circled) | epoch = J2000 | constell = Dorado | component1 = A | ra1 = | dec1 = | appmag_v1 = 3.2363.276 | component2 = B | ra2 = | dec2 = | appmag_v2 = 4.3 | r-i = −0.09 | b-v = −0.10 | u-b = −0.35 | component = A | class = A0IIIp | variable = ACV | component = B | class = B9IV | component1 = A | radial_v = 25.6 ± 0.9 | prop_mo_ra = 58.06 | prop_mo_dec = 12.73 | parallax = 19.34 | p_error = 0.31 | parallax_footnote = | component2 = B | prop_mo_ra2 = 42.83 | prop_mo_dec2 = 12.94 | reference = | period_unitless = 12.1 y | axis_unitless = 0.18″ | eccentricity = 0.80 | inclination = 31 | node = 140 | periastron = B1986 | periarg = 193 | component1 = A | mass = 3.33 ± 0.10 | radius = 3.5 ± 0.3 | luminosity_bolometric = 195 | gravity = 4.02 ± 0.07 | temperature = 11,588 | rotation = 2.94 days | component2 = B | mass2 = 2.7 | radius2 = 1.9 | luminosity_bolometric2 = 70 | temperature2 = 12,200 | names = | Simbad =alp+dor

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 ly.

::figure[src="https://upload.wikimedia.org/wikipedia/commons/3/30/AlphaDorLightCurve.png" caption="TESS]]'' data"] ::

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 naked-eye 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.

References

References

1. "alf Dor". AAVSO.
2. (1995-11-01). "VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)". VizieR Online Data Catalog.
3. van Leeuwen, F.. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics.
4. "Alpha Doradus".
5. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute.
6. "Entry 04340-5503". [[United States Naval Observatory]].
7. "Alpha Dor".
8. "The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates". Sternberg Astronomical Institute.
9. "Entry 04340-5503, discoverer code HJ3668, components AB-C". [[United States Naval Observatory]].
10. (April 1984). "Note on the orbit of alpha Doradus". The Observatory.
11. (June 1998). "Do SI stars undergo any rotational braking?". Astronomy and Astrophysics.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::