Sigma Centauri
Star in the constellation Centaurus
title: "Sigma Centauri" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["b-type-main-sequence-stars", "lower-centaurus-crux", "centaurus", "bayer-objects", "bright-star-catalogue-objects", "durchmusterung-objects", "henry-draper-catalogue-objects", "hipparcos-objects"] description: "Star in the constellation Centaurus" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/Sigma_Centauri" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Star in the constellation Centaurus ::
| name = σ Centauri | image = |image=Centaurus constellation map.svg|alt=|float=center|width=280 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=σ Centauri |x=740|y=642 | caption = Location of σ Centauri (circled in red) | epoch = J2000.0 | equinox = J2000.0 (ICRS) | constell = Centaurus | ra = | dec = | appmag_v = 3.91 | type = Main sequence | class = B3 V | b-v = −0.202 | u-b = −0.805 | r-i = | variable = | radial_v = | prop_mo_ra = −32.36 | prop_mo_dec = −12.51 | pm_footnote = | parallax = 7.92 | p_error = 0.18 | parallax_footnote = | absmag_v = −1.60 | source = | mass = | radius = 4.5 | luminosity = 1,101 | temperature = 15,744 | gravity = | metal_fe = | rotational_velocity = 169 | age_myr = | names = | Simbad = sig+Cen Sigma Centauri is a solitary star in the southern constellation of Centaurus. Its name is a Bayer designation that is Latinized from σ Centauri, and abbreviated Sigma Cen or σ Cen. This star is visible to the naked eye with an apparent visual magnitude of 3.91. A visual companion at an angular separation of along a position angle of was detected in 2010 using interferometry, but its association with Sigma Centauri remains undetermined as of 2013. The distance to Sigma Centauri, based upon an annual parallax shift of , is around 412 light years.
This is a B-type main sequence star with a stellar classification of B3 V. It is a helium-rich star, the most massive type of chemically peculiar star. Sigma Centauri has around 6.8 times the mass of the Sun and 4.5 times the Sun's radius. It has a relatively high rate of spin with a projected rotational velocity of 169 km/s, and is around 25 million years old. The star radiates 1,101 times the solar luminosity from its outer atmosphere at an effective temperature of 15,744 K. It is a member of the Lower Centaurus Crux component of the Scorpius–Centaurus association.
References
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| title=sig Cen | mode=cs2 | access-date=2017-01-12 }}
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