{{Short description|Star in the constellation Musca}} {{Starbox begin}} {{Starbox image | image = {{Location mark | image=Musca IAU.svg | float=center | width=240 | position=right | mark=Red circle.svg | mark_width=10 | mark_link=α Mus | x%=48.8 | y%=43.9 }} | caption=Location of α Muscae (circled) }} {{Starbox observe | epoch = [[J2000.0]] | ra = {{RA|12|37|11.01789}}<ref name=aaa474_2_653/> | dec = {{DEC|−69|08|08.0332}}<ref name=aaa474_2_653/> | appmag_v = +2.69<ref name=apjs15_459/> | constell = [[Musca (constellation)|Musca]] }} {{Starbox character | type = [[main sequence]]<ref name=jin2024/> | class = B2 IV–V<ref name=mnras410_1_190/> | b-v = −0.219<ref name=apjs15_459/> | u-b = −0.854<ref name=apjs15_459/> | variable = [[Beta Cephei variable|β Cep]]<ref name=aaa452_3_945/> }} {{Starbox astrometry | radial_v = +13<ref name=rgcrv/> | prop_mo_ra = −40.20<ref name=aaa474_2_653/> | prop_mo_dec = −12.80<ref name=aaa474_2_653/> | parallax = 10.34 | p_error = 0.11 | parallax_footnote = <ref name=aaa474_2_653/> | absmag_v = −2.2<ref name=aaa216_1_44/> }} {{Starbox detail | mass = {{val|8.8|0.1}}<ref name=mnras410_1_190/> | radius = {{solar radius calculator|type=logLT|1=3.63|logLerr=0.01|2=20417|Terr=0|decimals=2}}<ref name=Sharma2022/>{{Efn|name=radius}} | metal_fe = | age_myr = {{val|18.3|3.2}}<ref name=mnras410_1_190/> | gravity = 4.06<ref name=aaa216_1_44/> | luminosity = {{Val|4270|100|fmt=commas}}<ref name=Sharma2022/> | temperature = 20,400<ref name=Sharma2022/> | rotational_velocity = 114<ref name=apjss158_2_193/> }} {{Starbox catalog | names = {{odlist | B=α Mus | CD=−68 1104 | CPD=−68 1702 | FK5=474 | HD=109668 | HIP=61585 | HR=4798 | SAO=251974 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad=alf+Mus }} {{Starbox end}}
'''Alpha Muscae''', [[Romanization of Greek|Latinized]] from α Muscae, is a [[star]] in the southern [[circumpolar constellation]] of [[Musca (constellation)|Musca]]. With an [[apparent visual magnitude]] of +2.7,<ref name=apjs15_459/> it is the [[List of stars in Musca|brightest star]] in the constellation. The distance to this star has been determined using [[parallax]] measurements, giving an estimate of about {{Convert|315|ly|pc|abbr=off|lk=on}} from Earth.<ref name=aaa474_2_653/>
With a [[stellar classification]] of B2 IV-V,<ref name=mnras410_1_190/> this star appears to be in the process of [[stellar evolution|evolving]] away from the [[main sequence]] of stars like the Sun and turning a [[subgiant star]], as the supply of hydrogen at its core becomes exhausted. It is larger than the Sun, with nearly nine<ref name=mnras410_1_190/> times the mass and 5.2 times the radius.{{Efn|name=radius}} This star is radiating around 4,300 times as much luminosity as the Sun from its outer atmosphere at an [[effective temperature]] of 20,400 K,<ref name=aaa216_1_44/> giving it the blue-white hue of a [[B-type star]].<ref name=csiro/>
[[File:AlphaMusLightCurve.png|thumb|left|A [[light curve]] for Alpha Muscae, plotted from ''[[Transiting Exoplanet Survey Satellite|TESS]]'' data<ref name=MAST/>]] Alpha Muscae appears to be a [[Beta Cephei variable|Beta Cephei]] variable star. Telting and colleagues report it as a Beta Cephei with a high degree of confidence as they found regular pulsations in its spectrum in a high-resolution spectroscopy study published in 2006,<ref name=aaa452_3_945/> although Stankov and Handler (2005) listed it as a poor or rejected candidate in their ''Catalog of Galactic β Cephei Stars''.<ref name=apjss158_2_193/> The [[International Variable Star Index]] lists it as a Beta Cephei variable which varies in brightness from magnitude 2.68 to 2.73, with a period of 2.17 hours.<ref name="IVSI"/> Alpha Muscae is rotating rapidly with a [[projected rotational velocity]] of {{nowrap|114 km s<sup>−1</sup>}}<ref name=apjss158_2_193/> and has an estimated age of about 18 million years.<ref name=mnras410_1_190/>
This star is a [[proper motion]] member of the Lower Centaurus–Crux sub-group in the [[Scorpius–Centaurus association|Scorpius–Centaurus]] [[Stellar association|OB association]], the nearest such association of co-moving massive stars to the Sun.<ref name=aaa216_1_44/> Alpha Muscae has a [[peculiar velocity]] of 10 km s<sup>−1</sup>, which, while high, is not enough for it to be considered a [[runaway star]].<ref name=mnras410_1_190/>
In the culture of the indigenous [[Wardaman people]] of Australia, this star has the name Burangalul, referring to the "forehead band" of the [[boomerang]] constellation Buran, which is equivalent to Musca.<ref name=ASE/>
==Notes== {{Notelist|notes=
{{Efn|name=radius|1=Calculated, using the [[Stefan-Boltzmann law]] and the star's [[effective temperature]] and luminosity, with respect to the [[Sun|solar]] nominal effective temperature of 5,772 [[Kelvin|K]]:<math display="block">\sqrt{\biggl(\frac{5,772}{20,400}\biggr)^4 \cdot 10^{3.63}} = 5.22\ R_\odot.</math>}}
}}
== References == <references>
<ref name=aaa474_2_653>{{citation | last1=van Leeuwen | first1=F. | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 |date=November 2007 | pages=653–664 | doi=10.1051/0004-6361:20078357 | bibcode=2007A&A...474..653V | arxiv=0708.1752 | s2cid=18759600 }}</ref>
<ref name=Sharma2022>{{citation |doi=10.1093/mnras/stac1816 |title=Pulsating B stars in the Scorpius–Centaurus Association with TESS |year=2022 |last1=Sharma |first1=Awshesh N. |last2=Bedding |first2=Timothy R. |last3=Saio |first3=Hideyuki |last4=White |first4=Timothy R. |journal=Monthly Notices of the Royal Astronomical Society |volume=515 |issue=1 |pages=828–840 |doi-access=free |arxiv=2203.02582 | bibcode=2022MNRAS.515..828S}}</ref>
<ref name=MAST>{{cite web |title=MAST: Barbara A. Mikulski Archive for Space Telescopes |url=https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html |publisher=Space Telescope Science Institute |access-date=8 December 2021}}</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="IVSI">{{cite web |title=alf Mus |url=https://www.aavso.org/vsx/index.php?view=detail.top&oid=19955 |website=The International Variable Star Index |publisher=AAVSO |access-date=16 December 2022}}</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 | journal=Determination of Radial Velocities and Their Applications, Proceedings from IAU Symposium No. 30 | volume=30 | pages=57| location=University of Toronto | publisher=[[International Astronomical Union]] | bibcode=1967IAUS...30...57E }}</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=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=SIMBAD>{{citation | title=HD 109668 -- Variable Star of Beta Cep type | work=SIMBAD Astronomical Database | url=http://simbad.u-strasbg.fr/sim-id.pl?protocol=html&Ident=alpha+muscae | access-date=2007-01-29 }}</ref>
<ref name=aaa452_3_945>{{citation | display-authors=1 | last1=Telting | first1=J. H. | last2=Schrijvers | first2=C. | last3=Ilyin | first3=I. V. | last4=Uytterhoeven | first4=K. | last5=De Ridder | first5=J. | last6=Aerts | first6=C. | last7=Henrichs | first7=H. F. | title=A high-resolution spectroscopy survey of β Cephei pulsations in bright stars | journal=Astronomy and Astrophysics | volume=452 | issue=3 | pages=945–953 |date=June 2006 | doi=10.1051/0004-6361:20054730 | bibcode=2006A&A...452..945T | doi-access=free | hdl=2066/36162 | hdl-access=free }}</ref>
<ref name=apjss158_2_193>{{citation | last1=Stankov | first1=Anamarija | last2=Handler | first2=Gerald | title=Catalog of Galactic β Cephei Stars | journal=The Astrophysical Journal Supplement Series | volume=158 | issue=2 | pages=193–216 |date=June 2005 | doi=10.1086/429408 | bibcode=2005ApJS..158..193S |arxiv = astro-ph/0506495 | s2cid=119526948 }}</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 |url-status=dead |archive-url=https://web.archive.org/web/20041108073631/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html |archive-date=November 8, 2004 }}</ref>
<ref name=ASE>{{cite web |title=Burangalul |url=https://ase.exopla.net/index.php/Burangalul |website=All Skies Encyclopaedia |publisher=[[IAU Working Group on Star Names]] |access-date=1 July 2025}}</ref>
<ref name=jin2024>{{cite journal |last1=Jin |first1=Harim |last2=Langer |first2=Norbert |last3=Lennon |first3=Daniel J. |last4=Proffitt |first4=Charles R. |title=Boron depletion in Galactic early B-type stars reveals two different main sequence star populations |journal=Astronomy and Astrophysics |date=2024 |volume=690 |pages=A135 |doi=10.1051/0004-6361/202450896 |arxiv=2405.18266 |bibcode=2024A&A...690A.135J }}</ref>
</references>
{{Musca}} {{Sky|12|37|11.08|-|69|08|07.9|306}}
<!-- Properties --> [[Category:B-type main-sequence stars]] [[Category:B-type subgiants]] [[Category:Beta Cephei variables]] [[Category:Lower Centaurus Crux]] <!-- Other --> [[Category:Musca]] [[Category:Bayer objects|Muscae, Alpha]] [[Category:Durchmusterung objects|CD-68 01104]] [[Category:Henry Draper Catalogue objects|109668]] [[Category:Hipparcos objects|061585]] [[Category:Bright Star Catalogue objects|4798]] [[Category:Lucidae]]