Beta Octantis

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title: "Beta Octantis" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["a-type-subgiants", "a-type-main-sequence-stars", "octans", "bayer-objects", "durchmusterung-objects", "henry-draper-catalogue-objects", "hipparcos-objects", "bright-star-catalogue-objects", "astrometric-binaries"] description: "Astrometric binary star in the constellation Octans" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/Beta_Octantis" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Astrometric binary star in the constellation Octans ::

| name = β Octantis |image= |image=Octans constellation map.svg|alt=|float=center|width=280 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=Beta Octantis |x=432|y=498 |caption=Location of β Octantis (circled) | epoch = J2000 | constell = Octans | ra = | dec = | appmag_v = 4.13 | class = A9IV-V | b-v = +0.20 | u-b = +0.11 | radial_v = | prop_mo_ra = −54.49 | prop_mo_dec = +1.16 | parallax = 21.85 | p_error = 0.43 | parallax_footnote = | absmag_v = +0.83 | mass = 2.27 | radius = 3.2 | temperature = 8,006 | luminosity = 42 | rotational_velocity = 49 | gravity = 4.15 | metal_fe = −0.02 | age_myr=496 | names = | Simbad = Beta+Octantis

Beta Octantis, Latinized from β Octantis, is a probable astrometric binary star system in the southern circumpolar constellation of Octans. It is faintly visible to the naked eye with an apparent visual magnitude of 4.13. Based upon an annual parallax shift of 21.85 mas as seen from Earth, it is located about 149 light years from the Sun. It is moving away from the Sun with a radial velocity of +19 km/s.

Based upon a stellar classification of A9IV-V, the visible component is an evolving, white-hued A-type star with a spectrum that shows mixed traits of a main sequence and a subgiant star. It has an estimated 2.27 times the mass of the Sun and 3.2 times the Sun's radius. The star is around 500 million years old with a projected rotational velocity of 49 km/s. It is radiating 42 times the Sun's luminosity from its photosphere at an effective temperature of 8,006 K.

References

| last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=869–879 | date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E | arxiv=0806.2878 | s2cid=14878976 }}

References

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8. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal.
9. (2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters.

::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. ::