Beta Octantis

{{Short description|Astrometric binary star in the constellation Octans}}

{{Starbox begin

| name = β Octantis

}}

{{Starbox image

|image=

{{Location mark

|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)

}}

{{Starbox observe

| epoch = J2000

| constell = Octans

| ra = {{RA|22|46|03.51098}}{{cite journal | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | year=2007 | last1=Van Leeuwen | first1=F. | s2cid=18759600 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-S?HIP%20112405 Vizier catalog entry]

| dec = {{DEC|-81|22|53.8120}}

| appmag_v = 4.13{{cite journal | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | title=XHIP: An extended hipparcos compilation | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | s2cid=119257644 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=V/137D/XHIP&HIP=112405 Vizier catalog entry]

}}

{{Starbox character

| class = A9IV-V{{cite journal | bibcode=1995yCat.5050....0H | title=VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991) | journal=VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H | volume=5050 | last1=Hoffleit | first1=D. | last2=Warren | first2=W. H. | year=1995 }}

| b-v = +0.20{{cite journal | bibcode=2014JAVSO..42..443M | title=Sloan Magnitudes for the Brightest Stars | journal=The Journal of the American Association of Variable Star Observers | volume=42 | pages=443 | last1=Mallama | first1=A. | year=2014 | issue=2 }}[http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/other/JAVSO/42.443/ugriz&HD=214846 Vizier catalog entry]

| u-b = +0.11

}}

{{Starbox astrometry

| radial_v = {{Val|+19.0|0.6}}{{Cite journal | doi=10.1134/S1063773706110065 | bibcode=2006AstL...32..759G| title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system| journal=Astronomy Letters| volume=32| issue=11| pages=759–771| year=2006| last1=Gontcharov| first1=G. A.| arxiv=1606.08053 | s2cid=119231169}}

| prop_mo_ra = −54.49

| prop_mo_dec = +1.16

| parallax = 21.85

| p_error = 0.43

| parallax_footnote =

| absmag_v = +0.83

}}

{{Starbox detail

| mass = 2.27{{cite journal | arxiv=1201.2052 | bibcode=2012A&A...537A.120Z | doi=10.1051/0004-6361/201117691 | title=Rotational velocities of A-type stars | journal=Astronomy & Astrophysics | volume=537 | pages=A120 | year=2012 | last1=Zorec | first1=J. | last2=Royer | first2=F. | s2cid=55586789 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/A%2bA/537/A120/table1&HD=214846 Vizier catalog entry]

| radius = 3.2{{cite journal | bibcode=1999A&A...352..555A | arxiv=astro-ph/9911002 | title=Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures | journal=Astronomy and Astrophysics | volume=352 | pages=555–562 | last1=Allende Prieto | first1=C. | last2=Lambert | first2=D. L. | year=1999 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/A%2bA/352/555/table1&Name=HIP112405 Vizier catalog entry]

| temperature = 8,006{{cite journal | bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146 | arxiv=1501.03154 | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets | journal=The Astrophysical Journal | volume=804 | issue=2 | pages=146 | year=2015 | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A. | s2cid=33401607 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/ApJ/804/146/table5&HIP=112405 Vizier catalog entry]

| luminosity = 42

| rotational_velocity = 49

| gravity = 4.15

| metal_fe = −0.02{{cite journal | bibcode=2012AstL...38..771G | doi=10.1134/S1063773712120031 | arxiv=1606.08814 | title=Dependence of kinematics on the age of stars in the solar neighborhood | journal=Astronomy Letters | volume=38 | issue=12 | pages=771–782 | year=2012 | last1=Gontcharov | first1=G. A. | s2cid=118345778 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/PAZh/38/860/thin&HIP=112405 Vizier catalog entry]

| age_myr=496

}}

{{Starbox catalog

| names = {{odlist | B=β Oct | CPD=−82°889 | FK5=924 | HD=214846 | HIP=112405 | HR=8630 | SAO=258941 | GC=31712 }}

}}

{{Starbox reference

| Simbad = Beta+Octantis

}}

{{Starbox end}}

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.