{{Short description|Star in the constellation Lupus}} {{DISPLAYTITLE:Tau<sup>1</sup> Lupi}} {{other stars by Bayer designation|Tau Lupi{{!}}τ Lupi}} {{Starbox begin | name = Tau<sup>1</sup> Lupi }} {{Starbox image | image = {{Location mark |image=Lupus constellation map.svg|alt=|float=center|width=250 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=Tau1 Lupi |x=860|y=865 }} | caption = Location of τ<sup>1</sup> Lupi (circled in red) }} {{Starbox observe | epoch = [[J2000.0]] | equinox = [[J2000.0]] ([[International Celestial Reference System|ICRS]]) | constell = [[Lupus (constellation)|Lupus]] | ra = {{RA|14|26|08.22424}}<ref name=vanLeeuwen2007/> | dec = {{DEC|−45|13|17.1315}}<ref name=vanLeeuwen2007/> | appmag_v = 4.546<ref name=Hohle2010/> }} {{Starbox character | class = B2 IV<ref name=Bobylev2013/><ref name=Hohle2010/> | b-v = −0.146<ref name=Hohle2010/> | u-b = | r-i = | variable = [[Beta Cephei variable|β Cep]]<ref name=Cuypers1987/> }} {{Starbox astrometry | radial_v = {{Val|−21.5|2.8}}<ref name=Bobylev2013/> | prop_mo_ra = −13.09<ref name=vanLeeuwen2007/> | prop_mo_dec = −14.67<ref name=vanLeeuwen2007/> | parallax = 2.99 | p_error = 0.21 | parallax_footnote = <ref name=vanLeeuwen2007/> | absmag_v = −3.05<ref name=Anderson2012/> }} {{Starbox detail | source = | mass = {{Val|9.98|0.63}}<ref name=Hohle2010/> | radius = 7.1<ref name=PasinettiFracassini2001/> | luminosity = 3,831<ref name=Mcdonald2012/> | luminosity_bolometric = 11,321<ref name=Hohle2010/> | temperature = 15,273<ref name=Mcdonald2012/> | gravity = | metal_fe = {{Val|−0.39|0.16}}<ref name=Daszkiewicz2005/> | rotational_velocity = 30<ref name=Aerts1999/> | rotation = | age_myr = {{Val|20.8|0.9}}<ref name=Tetzlaff2011/> }} {{Starbox catalog | names = [[Bayer designation|τ<sup>1</sup> Lup]], [[Durchmusterung|CD]]−44°9322, [[FK5]] 1377, [[Henry Draper Catalogue|HD]] 126341, [[Hipparcos Catalogue|HIP]] 70574, [[Harvard Revised catalogue|HR]] 5395, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 224919<ref name=SIMBAD/> }} {{Starbox reference | Simbad = tau1+Lup }} {{Starbox end}}
'''Tau<sup>1</sup> Lupi''', [[Latinisation of names|Latinized]] from '''τ<sup>1</sup> Lupi''', is a solitary<ref name=Eggleton2008/> [[star]] in the southern [[constellation]] of [[Lupus (constellation)|Lupus]]. It is visible to the naked eye with an [[apparent visual magnitude]] of 4.5.<ref name=Hohle2010/> Based upon an annual [[stellar parallax|parallax shift]] of only 2.99 [[milliarcsecond|mas]] as seen from Earth, it is located about 1,090 [[light year]]s from the [[Sun]]. Tau<sup>1</sup> Lupi may be a [[runaway star]]<ref name=Tetzlaff2011/> having a [[peculiar velocity]] of {{Val|32.6|3.6|u=km/s}}.<ref name=Bobylev2013/> It is a member of the Upper Centaurus–Lupus sub-group of the nearby [[Sco OB2]] association.<ref name=deGeus1989/>
[[File:Tau1LupLightCurve.png|thumb|left|250px|A [[light curve]] for Tau<sup>1</sup> Lupi, plotted from ''[[Transiting Exoplanet Survey Satellite|TESS]]'' data<ref name=MAST/>]]
This is a [[B-type star|B-type]] [[subgiant star]] with a [[stellar classification]] of B2 IV.<ref name=Bobylev2013/><ref name=Hohle2010/> It was determined to be a [[Beta Cephei variable]] based on observations during 1955 at the [[Cape Observatory]].<ref name=Pagel1956/> Tau<sup>1</sup> Lupi shows a steady period of 0.17736934 days, corresponding to a frequency of 5.637953 cycles per day, with an [[amplitude]] of 0.035 in visual magnitude.<ref name=Cuypers1987/><ref name=stankov2005/> It has around 10<ref name=Hohle2010/> times the [[solar mass|mass of the Sun]] and 7<ref name=PasinettiFracassini2001/> times the [[solar radius|Sun's radius]].
The star shows an [[infrared excess]], which is unusual for a non-[[Be star|emission star]] of this class. The inner edge of the dust lies at a distance of 980 [[Astronomical Unit|AU]] from the star with a temperature of 190 K, and it extends outward to as much as 50,000 AU where the temperature drops to 40 K. This optically thin dust is not related to the pulsational behavior of the star.<ref name=Aerts1999/> {{clear left}} ==References== <references>
<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=vanLeeuwen2007>{{citation | title=Validation of the new Hipparcos reduction | last1=van Leeuwen | first1=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | date=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | s2cid=18759600 | postscript=. }}</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=deGeus1989>{{citation | display-authors=1 | 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 | postscript=. }}</ref>
<ref name=Tetzlaff2011>{{citation | display-authors=1 | 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 | postscript=. | bibcode=2011MNRAS.410..190T | arxiv=1007.4883 | s2cid=118629873 }}</ref>
<ref name=Aerts1999>{{citation | title=HD 42927 and HD 126341: two pulsating B stars surrounded by circumstellar dust | last1=Aerts | first1=C. | last2=De Boeck | first2=I. | last3=Malfait | first3=K. | last4=De Cat | first4=P. | journal=Astronomy and Astrophysics | volume=347 | pages=524–531 | date=July 1999 | bibcode=1999A&A...347..524A | postscript=. }}</ref>
<ref name=PasinettiFracassini2001>{{citation | display-authors=1 | last1=Pasinetti Fracassini | first1=L. E. | last2=Pastori | first2=L. | last3=Covino | first3=S. | last4=Pozzi | first4=A. | title=Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) | edition=3rd | journal=Astronomy and Astrophysics | volume=367 | issue=2 | pages=521–524 | date=February 2001 | doi=10.1051/0004-6361:20000451 | bibcode=2001A&A...367..521P | arxiv=astro-ph/0012289 | s2cid=425754 | postscript=. }}</ref>
<ref name=Daszkiewicz2005>{{citation | title=Metallicity of mono- and multiperiodic β Cephei stars | last1=Daszyńska-Daszkiewicz | first1=J. | last2=Niemczura | first2=E. | journal=Astronomy and Astrophysics | postscript=. | volume=433 | issue=3 | pages=1031–1035 | date=April 2005 | doi=10.1051/0004-6361:20040397 | bibcode=2005A&A...433.1031D |arxiv = astro-ph/0410442 | s2cid=119340011 }}</ref>
<ref name=Eggleton2008>{{citation | 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 | postscript=. }}</ref>
<ref name=Hohle2010>{{citation | display-authors=1 | last1=Hohle | first1=M. M. | last2=Neuhäuser | first2=R. | last3=Schutz | first3=B. F. | title=Masses and luminosities of O- and B-type stars and red supergiants | journal=Astronomische Nachrichten | volume=331 | issue=4 | page=349 | date=April 2010 | doi=10.1002/asna.200911355 | bibcode=2010AN....331..349H | arxiv=1003.2335 | s2cid=111387483 | postscript=. }}</ref>
<ref name=Mcdonald2012>{{citation | display-authors=1 | last1=McDonald | first1=I. | last2=Zijlstra | first2=A. A. | last3=Boyer | first3=M. L. | title=Fundamental Parameters and Infrared Excesses of Hipparcos Stars | journal=Monthly Notices of the Royal Astronomical Society | volume=427 | issue=1 | pages=343–57 | date=2012 | bibcode=2012MNRAS.427..343M | arxiv=1208.2037 | doi=10.1111/j.1365-2966.2012.21873.x | doi-access=free | s2cid=118665352 | postscript=. }}</ref>
<ref name=Bobylev2013>{{citation | title=Galactic kinematics from a sample of young massive stars | last1=Bobylev | first1=V. V. | last2=Bajkova | first2=A. T. | journal=Astronomy Letters | postscript=. | volume=39 | issue=8 | pages=532–549 | date=August 2013 | doi=10.1134/S106377371308001X | bibcode=2013AstL...39..532B |arxiv = 1307.1677 | s2cid=118568203 }}</ref>
<ref name=Pagel1956>{{citation | title=Results of a search for bright β Cephei variables in the southern sky | last1=Pagel | first1=B. E. J. | postscript=. | journal=Monthly Notices of the Royal Astronomical Society | volume=116 | page=10 | year=1956 | doi=10.1093/mnras/116.1.10 | bibcode=1956MNRAS.116...10P | doi-access=free}}</ref>
<ref name=Cuypers1987>{{citation | title=New observations and frequency analysis of the Beta Cephei star Tau1 Lupi | last1=Cuypers | first1=J. | journal=Astronomy and Astrophysics Supplement Series | volume=69 | issue=3 | date=June 1987 | pages=445–449 | bibcode=1987A&AS...69..445C | postscript=. }}</ref>
<ref name=stankov2005>{{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 | year=2005 | pages=193–216 | issn=0067-0049 | doi=10.1086/429408 | postscript=. | arxiv=astro-ph/0506495 | bibcode=2005ApJS..158..193S |s2cid=119526948}}</ref>
<ref name=SIMBAD>{{citation | title=tau01 Lup -- Variable Star of beta Cep type | work=SIMBAD Astronomical Database | publisher=Centre de Données astronomiques de Strasbourg | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=tau01+Lup | accessdate=2017-03-10 | postscript=. }}</ref>
</references>
{{Stars of Lupus|state=collapsed}}
[[Category:B-type subgiants]] [[Category:Beta Cephei variables]] [[Category:Runaway stars]] [[Category:Lupus (constellation)]] [[Category:Bayer objects|Lupi, Tau1]] [[Category:Durchmusterung objects|CD-44 09322]] [[Category:Henry Draper Catalogue objects|126341]] [[Category:Hipparcos objects|070574]] [[Category:Bright Star Catalogue objects|5395]] [[Category:Upper Centaurus Lupus]]