{{short description|Star in the constellation of Lupus}} {{Starbox begin | name = δ Lupi }} {{Starbox image | image= {{Location mark |image=Lupus constellation map.svg|alt=|float=center|width=240 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=δ Lup |x=472|y=657 }} |caption=Location of δ Lupi (circled) }} {{Starbox observe | epoch = [[J2000.0]] | ra = {{RA|15|21|22.32168}}<ref name=aaa474_2_653/> | dec = {{DEC|-40|38|51.0738}}<ref name=aaa474_2_653/> | appmag_v = 3.20 - 3.24<ref name=gcvs/> | constell = [[Lupus (constellation)|Lupus]] }} {{Starbox character | class = B1.5 IV<ref name=apj157_313/> | b-v = −0.224<ref name=apjs15_459/> | u-b = −0.910<ref name=apjs15_459/> | variable = [[Beta Cephei variable|β Cep]]<ref name=mnras377_2_645/><ref name=gcvs/> }} {{Starbox astrometry | radial_v = +0.2<ref name=rgcrv/> | prop_mo_ra = −19.49<ref name=aaa474_2_653/> | prop_mo_dec = −25.29<ref name=aaa474_2_653/> | parallax = 3.69 | p_error = 0.54 | parallax_footnote = <ref name=aaa474_2_653/> | absmag_v = −3.1<ref name=aaa216_1_44/> }} {{Starbox detail | mass = {{val|11.9|0.2}}<ref name=mnras410_1_190/> | radius = 6.1<ref name=mnras189_601/> | luminosity = 10,000<ref name=mnras410_1_190/> | temperature = 22,908<ref name=mnras410_1_190/> | metal_fe = {{val|-0.25|0.11}}<ref name=aaa433_2_659/> | gravity = 3.86<ref name=mnras410_1_190/> | rotational_velocity = 230<ref name=coapa239_1/> | age_myr = {{val|15.4|1.3}}<ref name=mnras410_1_190/> }} {{Starbox catalog | names = [[Cordoba Durchmusterung|CD]]−40°9538, [[Catalogues of Fundamental Stars|FK5]] 1402, [[Henry Draper catalogue|HD]] 136298, [[Hipparcos catalogue|HIP]] 75141, [[Harvard Revised catalogue|HR]] 5695, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 225691, UBV 13201<ref name=SIMBAD/> }} {{Starbox reference | Simbad=del+Lup }} {{Starbox end}} '''Delta Lupi''' (δ Lupi, δ Lup) is a [[star]] in the southern [[circumpolar constellation]] of [[Lupus (constellation)|Lupus]]. In traditional [[Chinese language|Chinese]] astronomy, it is "the 2nd (star) of the Cavalry Officer" (騎官二). With an [[apparent visual magnitude]] of 3.2, it is the fourth-brightest star in the constellation. The distance to this star has been measured using the [[parallax]] technique, yielding an estimate of roughly 900 [[light-year]]s with a 15% [[margin of error]].<ref name=aaa474_2_653/>
[[File:DeltaLupLightCurve.png|thumb|left|A [[light curve]] for Delta Lupi, plotted from ''[[Transiting Exoplanet Survey Satellite|TESS]]'' data<ref name=MAST/>]] The [[stellar spectrum|spectrum]] of this star matches a [[stellar classification]] of B1.5 IV,<ref name=apj157_313/> which indicates this star has entered the [[subgiant star|subgiant]] stage and is in the process of [[stellar evolution|evolving]] into a [[giant star]]. It is radiating around 10,000 times the luminosity of the [[Sun]] from its outer atmosphere at an effective temperature of 23,000 [[Kelvin|K]], giving it a blue-white hue. This star has nearly 12 times the mass of the Sun and is roughly 15 million years old.<ref name=mnras410_1_190/>
Delta Lupi is a [[Beta Cephei variable|Beta Cephei]] [[variable star]] that undergoes periodic pulsations. It has a single period of variability lasting 0.1655 days, or six cycles per day.<ref name=mnras377_2_645/> This 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/> {{clear left}}
== See also == * [[Traditional Chinese star names#Lupus]]
== References == {{Reflist|refs=
<ref name=gcvs>{{cite journal |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 GCVS 5.1 |journal=Astronomy Reports |date=January 2017 |volume=61 |issue=1 |pages=80–88 |doi=10.1134/S1063772917010085 |issn=1063-7729 |bibcode=2017ARep...61...80S|s2cid=255195566 }}</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=11 December 2022}}</ref>
<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=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=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=mnras189_601>{{citation | display-authors=1 | last1=Underhill | first1=A. B. | last2=Divan | first2=L. | last3=Prevot-Burnichon | first3=M.-L. | last4=Doazan | first4=V. | title=Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars | journal=Monthly Notices of the Royal Astronomical Society | volume=189 | pages=601–605 |date=November 1979 | issue=3 | bibcode=1979MNRAS.189..601U | doi=10.1093/mnras/189.3.601| doi-access=free }}</ref>
<ref name=SIMBAD>{{cite simbad | title=del Lup | accessdate=2007-01-18 }}</ref>
<ref name=apj157_313>{{citation | last1=Hiltner | first1=W. A. | last2=Garrison | first2=R. F. | last3=Schild | first3=R. E. | title=MK spectral types for bright southern OB stars | journal=Astrophysical Journal | volume=157 | page=313 |date=July 1969 | doi=10.1086/150069 | bibcode=1969ApJ...157..313H | doi-access=free }}</ref>
<ref name=rgcrv>{{cite conference | 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 | volume=30 | page=57 | conference=IAU Symposium no. 30 | book-title=Determination of Radial Velocities and their Applications | 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 | page=1 | bibcode=1970CoAsi.239....1B }}</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=mnras377_2_645>{{citation | last1=Smolec | first1=R. | last2=Moskalik | first2=P. | title=Amplitude saturation in β Cephei models | journal=Monthly Notices of the Royal Astronomical Society | volume=377 | issue=2 | pages=645–656 |date=May 2007 | doi=10.1111/j.1365-2966.2007.11620.x | doi-access=free | bibcode=2007MNRAS.377..645S |arxiv = astro-ph/0702406 | s2cid=17908442 }}</ref>
<ref name=aaa433_2_659>{{citation | last1=Niemczura | first1=E. | last2=Daszyńska-Daszkiewicz | first2=J. | title=Metallicities of the β Cephei stars from low-resolution ultraviolet spectra | journal=Astronomy and Astrophysics | volume=433 | issue=2 | pages=659–669 |date=April 2005 | doi=10.1051/0004-6361:20040396 | bibcode=2005A&A...433..659N |arxiv = astro-ph/0410440 | s2cid=14295631 }}. Note: value taken from [m/H].</ref>
}}
{{Stars of Lupus}}
[[Category:Bayer objects|Lupi, Delta]] [[Category:Lupus (constellation)]] [[Category:Beta Cephei variables]] [[Category:B-type subgiants]] [[Category:Upper Centaurus Lupus]] [[Category:Bright Star Catalogue objects|5695]] [[Category:Hipparcos objects|075141]] [[Category:Henry Draper Catalogue objects|136298]] [[Category:Durchmusterung objects|CD-40 09538]]