Mu Centauri: Difference between revisions

Revision as of 22:00, 22 January 2007

Latest revision as of 22:58, 9 March 2025

(76 intermediate revisions by 37 users not shown)

Line 1:

{{Short description|Variable star in the constellation Centaurus}}

{{Starbox begin |

{{Starbox begin}}

| name=μ Centauri

{{Starbox image

| image =

{{Location mark

| image=Centaurus constellation map.svg

| float=center | width=280 | position=right

| mark=Red circle.svg | mark_width=10 | mark_link=μ Cen

| x=442 | y=448

}}

| caption = Location of μ Centauri (circled)

}}

{{Starbox observe

| epoch = [[J2000.0]]

| constell = [[Centaurus]]

| ra = {{RA|13|49|36.98863}}<ref name=aaa474_2_653/>

| ra=13^h49^m37.0^s

| dec = {{DEC|−42|28|25.4296}}<ref name=aaa474_2_653/>

| dec=−42°28′26″

| appmag_v = {{nowrap|+3.42<ref name=apjs15_459/> (+2.92 to +3.49)<ref name=gcvs/>}}

| appmag_v=+3.47

}}

{{Starbox character

| class = B2V:e<ref name=B2IV-Vemk/>

| b-v = −0.17205<ref name=apjs15_459/>

| u-b = −0.72854<ref name=apjs15_459/>

| variable = [[Gamma Cassiopeiae variable|γ Cas]]<ref name=gcvs/>

}}

{{Starbox astrometry

| radial_v = +9.1<ref name=rgcrv/>

| prop_mo_ra =−23 −24.8525<ref name=aaa474_2_653/>

| prop_mo_dec =−19 −18.2264<ref name=aaa474_2_653/>

| absmag_v = −2.5648<ref name=Anderson2012/>

| parallax = 6.1945

| p_error = 0.7116

| parallax_footnote = <ref name=aaa474_2_653/>

| dist_ly=527

}}

| dist_pc=162

{{Starbox detail

| mass = {{val|9.1|0.2}}<ref name=mnras410_1_190/>

| radius = 4.21 (equatorial)<br>{{Val|3.4|0.3}} (polar)<ref name=aaa369_1058/>

| gravity = 3.86 (equatorial)<br>4.33 (polar)<ref name=aaa369_1058/>

| metal_fe =

| rotation = 11.615 hours<ref name=aaa369_1058/>

| age_myr = {{val|19.8|1.7}}<ref name=mnras410_1_190/>

| luminosity = 2,090<ref name=aaa369_1058/>

| temperature = 17,600 (equatorial)<br>{{Val|23200|200|fmt=commas}} (polar)<ref name=aaa369_1058/>

| rotational_velocity = 194<ref name=coapa239_1/>

}}

{{Starbox catalog

| names = {{odlist | B=μ Cen | CD=−41°8172 | FK5=508 | HD=120324 | HIP=67472 | HR=5193 | SAO=224471 }}

| names=[[Harvard Revised catalogue|HR]]&nbsp;5193, [[Henry Draper Catalogue|HD]]&nbsp;120324, [[Cordoba Durchmusterung|CD]]−41°8172, [[Fifth Fundamental Catalogue|FK5]]&nbsp;508, [[Hipparcos catalogue|HIP]]&nbsp;67472, [[Smithsonian Astrophysical Observatory catalogue|SAO]]&nbsp;224471, GC&nbsp;18667, CCDM&nbsp;J13496-4228}}

}}

{{Starbox reference

| Simbad=HD+120324

}}

{{Starbox end}}

'''Mu Centauri''' (μ Cen / μ Centauri) is a [[star]] in the [[constellation]] [[Centaurus]]. The name '''Kabkent''' or '''''Kalb al Kentaurus''''' is sometimes applied to this star, as well as to [[Nu Centauri]] and [[Phi Centauri]], because they mark the heart of the centaur. Mu Centauri is approximately 527 [[light year]]s from [[Earth]].

'''Mu Centauri''', [[Latinisation of names|Latinized]] from μ Centauri, is a third-magnitude [[star]] in the southern [[constellation]] of [[Centaurus]]. With the stars [[Nu Centauri|ν]] and [[Phi Centauri|φ Centauri]], it marks what has been traditionally portrayed as "''dextro Latere''" (the right side) of the Centaur.[https://web.archive.org/web/20071115020105/http://astro.isi.edu/reference/almagest.html] The [[apparent visual magnitude]] of this star is 3.42,<ref name=apjs15_459/> making it one of the [[List of stars in Centaurus|brighter members]] of the constellation. The distance to this star can be estimated directly using [[parallax]] measurements, which yield a value of roughly 510&nbsp;[[light year]]s (155&nbsp;[[parsec]]s) from [[Earth]].<ref name=aaa474_2_653/>

μ Centauri is a blue-white [[stellar classification|B-type]] [[subgiant]] with a mean [[apparent magnitude]] of +3.47. It is classified as a [[Gamma Cassiopeiae variable|Gamma Cassiopeiae type]] [[variable star]] and its brightness varies from magnitude +2.92 to +3.47.

[[File:MuCenLightCurve.png|thumb|left|A [[Photometric_system#Photometric_letters|visual band]] [[light curve]] for Mu Centauri, plotted from data published by Aguayo ''et al.'' (2018)<ref name="Aguayo"/>]]

The [[stellar spectrum|spectrum]] of Mu Centauri is considered to be a standard for a B2 [[Be star]] with the [[stellar classification]] of B2V:e.<ref name=mk/> The 'e' suffix is used to mark the presence of [[emission line]]s, caused by a circumstellar disk of hot gas that was formed from material ejected from the star. Mu Centauri is a pulsating variable star that has multiple non-radial cycles with a primary period of 0.503 days. Three other pulsation cycles have a similar period, while two have a shorter interval of about 0.28 days. It undergoes outburst events that result in the transfer of additional material to the surrounding disk.<ref name=aaa333_125/> During these outbursts, the star can experience transient periodicities.<ref name=aaa411_229/> Mu Centauri is classified as a [[Gamma Cassiopeiae variable|Gamma Cassiopeiae type]] [[variable star]] and its brightness varies from magnitude +2.92 to +3.49.<ref name=gcvs/>

This star is spinning rapidly, with a [[projected rotational velocity]] of 194,<ref name=coapa239_1/> km s⁻¹ and is completing a full rotation in about 11.615 hours. The equatorial [[azimuth]]al velocity is around 85% of the critical velocity where the star would start to break up, resulting a pronounced [[equatorial bulge]] that is about 26% wider than the radius at the poles. Because of the [[oblate spheroid]]al shape of this star, the polar region is at a higher temperature than the equator—23,000&nbsp;K versus 17,600&nbsp;K respectively. Likewise, the gravitational force at the poles is greater than along the equator. The axis of rotation of the star is tilted by an angle of about (19 ± 3)° to the line of sight from the Earth.<ref name=aaa369_1058/>

At an estimated age of nearly 20 million years,<ref name=mnras410_1_190/> this star is around 55–65% of the way through its evolutionary period on the [[main sequence]] of core [[hydrogen burning]] stars.<ref name=aaa441_1_235/> It has around nine<ref name=mnras410_1_190/> times the mass of the Sun and four<ref name=aaa441_1_235/> times the Sun's radius, but emits over 2,000<ref name=aaa369_1058/> times as much energy as the Sun. The outer atmosphere has a mean [[effective temperature]] of 22,410&nbsp;K,<ref name=aaa441_1_235/> giving the star a blue-white hue.<ref name=csiro/>

This star is a [[proper motion]] member of the Upper Centaurus–Lupus sub-group in the

[[Scorpius–Centaurus association|Scorpius–Centaurus]] [[Stellar association|OB association]],

the nearest such co-moving association of massive stars to the Sun.<ref name=aaa216_1_44/>

==References==

{{reflist|30em|refs=

<ref name=aaa474_2_653>{{cite journal | first=F. | last=van Leeuwen |date=November 2007 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 |arxiv = 0708.1752 | s2cid=18759600 }}</ref>

<ref name=Anderson2012>{{citation

| title=XHIP: An extended hipparcos compilation

| last1=Anderson | first1=E. | last2=Francis | first2=Ch.

| journal=Astronomy Letters

| volume=38 | issue=5 | pages=331 | year=2012

| bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015

| arxiv=1108.4971 | s2cid=119257644 | postscript=. }}</ref>

<ref name="Aguayo">{{cite journal |last1=Aguayo |first1=G. |last2=Mennickent |first2=R. E. |last3=Granada |first3=A. |last4=Otero |first4=S. |title=Multi-epoch L-band Spectroscopy of the Be Star μ Centauri Prior to Outburst |journal=The Astronomical Journal |date=October 2018 |volume=156 |issue=4 |page=174 |bibcode=2018AJ....156..174A |doi=10.3847/1538-3881/aad5db |s2cid=125167180 |doi-access=free |hdl=11336/82431 |hdl-access=free }}</ref>

<ref name=rgcrv>{{citation | last=Evans | first=D. S. | date=June 20–24, 1966 | editor1-last=Batten | editor1-first=Alan Henry | editor2-last=Heard | editor2-first=John Frederick | title=The Revision of the General Catalogue of Radial Velocities | work=Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 | volume=30 | page=57 | ___location=University of Toronto | publisher=[[International Astronomical Union]] | bibcode=1967IAUS...30...57E }}</ref>

<ref name=coapa239_1>{{cite journal | last1=Bernacca | first1=P. L. | last2=Perinotto | first2=M. | title=A catalogue of stellar rotational velocities | journal=Contributi Osservatorio Astronomico di Padova in Asiago | volume=239 | issue=1 | date=1970 | bibcode=1970CoAsi.239....1B }}</ref>

<ref name=mnras410_1_190>{{citation | last1=Tetzlaff | first1=N. | last2=Neuhäuser | first2=R. | last3=Hohle | first3=M. M. | title=A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=410 | issue=1 | pages=190–200 |date=January 2011 | doi=10.1111/j.1365-2966.2010.17434.x | doi-access=free | bibcode=2011MNRAS.410..190T |arxiv = 1007.4883 | s2cid=118629873 }}</ref>

<ref name=aaa441_1_235>{{citation | last1=Zorec | first1=J. | last2=Frémat | first2=Y. | last3=Cidale | first3=L. | title=On the evolutionary status of Be stars. I. Field Be stars near the Sun | journal=Astronomy and Astrophysics | volume=441 | issue=1 | pages=235–248 |date=October 2005 | doi=10.1051/0004-6361:20053051 | bibcode=2005A&A...441..235Z |arxiv = astro-ph/0509119 | s2cid=17592657 }}</ref>

<ref name=aaa411_229>{{citation | last1=Rivinius | first1=Th. | last2=Baade | first2=D. | last3=Štefl | first3=S. | title=Non-radially pulsating Be stars | journal=Astronomy and Astrophysics | volume=411 | pages=229–247 |date=November 2003 | issue=2 | doi=10.1051/0004-6361:20031285 | bibcode=2003A&A...411..229R | doi-access=free }}</ref>

<ref name=aaa369_1058>{{citation | display-authors=1 | last1=Rivinius | first1=Th. | last2=Baade | first2=D. | last3=Štefl | first3=S. | last4=Townsend | first4=R. H. D. | last5=Stahl | first5=O. | last6=Wolf | first6=B. | last7=Kaufer | first7=A. | title=Stellar and circumstellar activity of the Be star mu Centauri. III. Multiline nonradial pulsation modeling | journal=Astronomy and Astrophysics | volume=369 | pages=1058–1077 |date=April 2001 | doi=10.1051/0004-6361:20010185 | bibcode=2001A&A...369.1058R | doi-access=free }}</ref>

<ref name=aaa333_125>{{citation | display-authors=1 | last1=Rivinius | first1=Th. | last2=Baade | first2=D. | last3=Stefl | first3=S. | last4=Stahl | first4=O. | last5=Wolf | first5=B. | last6=Kaufer | first6=A. | title=Stellar and circumstellar activity of the Be star MU Centauri. I. Line emission outbursts | journal=Astronomy and Astrophysics | volume=333 | pages=125–140 |date=May 1998 | bibcode=1998A&A...333..125R }}</ref>

<ref name=csiro>{{citation | title=The Colour of Stars | date=December 21, 2004 | work=Australia Telescope, Outreach and Education | publisher=[[Commonwealth Scientific and Industrial Research Organisation]] | url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html | access-date=2012-01-16 | archive-url=https://web.archive.org/web/20120318151427/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html | archive-date=March 18, 2012 | url-status=dead }}</ref>

<ref name=apjs15_459>{{citation | last1=Gutierrez-Moreno | first1=Adelina | last2=Moreno | first2=Hugo | title=A photometric investigation of the Scorpio-Centaurus association | journal=Astrophysical Journal Supplement | volume=15 | page=459 |date=June 1968 | bibcode=1968ApJS...15..459G | doi=10.1086/190168 | doi-access=free }}</ref>

<ref name=gcvs>{{cite journal

| display-authors=1 | last1=Samus | first1=N. N.

| last2=Kazarovets | first2=E. V. | last3=Durlevich | first3=O. V.

| last4=Kireeva | first4=N. N. | last5=Pastukhova | first5=E. N.

| title=General Catalogue of Variable Stars

| version=5.1 | journal=Astronomy Reports

| year=2017 | volume=61 | issue=1 | pages=80–88

| bibcode=2017ARep...61...80S | s2cid=125853869

| doi=10.1134/S1063772917010085 }}</ref>

<ref name=aaa216_1_44>{{citation | last1=de Geus | first1=E. J. | last2=de Zeeuw | first2=P. T. | last3=Lub | first3=J. | title=Physical parameters of stars in the Scorpio-Centaurus OB association | journal=Astronomy and Astrophysics | volume=216 | issue=1–2 | pages=44–61 |date=June 1989 | bibcode=1989A&A...216...44D }}</ref>

<ref name=mk>{{cite journal|bibcode=1978rmsa.book.....M|title=Revised MK Spectral Atlas for stars earlier than the sun|journal=Williams Bay: Yerkes Observatory|last1=Morgan|first1=W. W|last2=Abt|first2=Helmut A|last3=Tapscott|first3=J. W|year=1978}}</ref>

}}

{{Stars of Centaurus}}

{{var-star-stub}}

{{DEFAULTSORT:Mu Centauri}}

<!-- Properties -->

[[Category:B-type main-sequence stars]]

[[Category:Gamma Cassiopeiae variable stars]]

[[Category:Upper Centaurus Lupus]]

<!-- Other -->

[[Category:Centaurus]]

[[Category:Bayer objects|Centauri, Mu]]

[[Category:Blue-whiteDurchmusterung subgiantsobjects]]

[[Category:CentaurusHenry constellationDraper Catalogue objects|120324]]

[[Category:GammaHipparcos Cassiopeiae variablesobjects|067472]]

[[Category:Bright Star Catalogue objects|5193]]