Xi1 Centauri
Star in the constellation Centaurus
title: "Xi1 Centauri" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["a-type-main-sequence-stars", "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/Xi1_Centauri" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Star in the constellation Centaurus ::
| name = ξ1 Centauri | image = | image=Centaurus constellation map.svg | float=center | width=280 | position=right | mark=Red circle.svg | mark_width=10 | mark_link=ξ1 Cen | x=614| y=607 | caption = Location of ξ1 Centauri (circled) | epoch = J2000.0 | equinox = J2000.0 (ICRS) | constell = Centaurus | ra = | dec = | appmag_v = +4.83 | type = Main sequence | class = A0 V | b-v = +0.030 | u-b = +0.014 | r-i = | variable = | radial_v = | prop_mo_ra = −47.858 | prop_mo_dec = −11.496 | pm_footnote = | parallax = 14.8276 | p_error = 0.1073 | parallax_footnote = | absmag_v = +0.68 | source = | mass = 2.39 | radius = 2.7 | luminosity = 43.2 | temperature = | gravity = | metal_fe = | rotational_velocity = 185 | age_myr = 125 | names = | Simbad = ksi01+Cen
::figure[src="https://upload.wikimedia.org/wikipedia/commons/7/77/NGC_4945_cut_test_(21818932856).jpg" caption="ξ1 Cen is the brightest star in the picture, at the right of the galaxy [[NGC 4945]]."] ::
Xi1 Centauri is a solitary star in the southern constellation of Centaurus. Its name is a Bayer designation that is Latinized from ξ1 Centauri, and abbreviated Xi1 Cen or ξ1 Cen. This star is visible to the naked eye with an apparent visual magnitude of +4.83. With an annual parallax shift of , it is located around 220 light years from the Sun. At that distance, the apparent visual magnitude of the star is diminished by an interstellar extinction factor of 0.10 due to intervening dust. Just 17 arc minutes to the east of Xi1 Centauri lies the galaxy NGC 4945.
This is an A-type main sequence star with a stellar classification of A0 V. It is about 125 million years old with a relatively high rate of spin, having a projected rotational velocity of 185 km/s. The star has an estimated 2.4 times the mass of the Sun and about 2.7 times the Sun's radius. It is radiating 43 times the solar luminosity from its outer atmosphere at an effective temperature of 10,462 K.
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