{{short description|Star in the constellation Lupus}} {{DISPLAYTITLE:Psi<sup>1</sup> Lupi}} {{Starbox begin | name = ψ<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=Psi1 Lupi |x=320|y=415 }} | caption = Location of ψ<sup>1</sup> Lupi (circled in red) }} {{Starbox observe | epoch = J2000 | constell = [[Lupus (constellation)|Lupus]]<ref name=Anderson2012/> | ra = {{RA|15|39|45.97931}}<ref name=GaiaDR2/> | dec = {{DEC|−34|24|42.9073}}<ref name=GaiaDR2/> | appmag_v = +4.663<ref name=alves2000/> }} {{Starbox character | type = [[red clump]]<ref name=alves2000/> | class = G8/K0 III<ref name=houk/> | b-v = {{Val|0.964|0.047}}<ref name=Anderson2012/> | u-b = | variable = }} {{Starbox astrometry | radial_v = {{Val|−23.1|0.8}}<ref name=Anderson2012/> | prop_mo_ra = +6.123<ref name=GaiaDR2/> | prop_mo_dec = −11.767<ref name=GaiaDR2/> | parallax = 15.7610 | p_error = 0.2700 | parallax_footnote = <ref name=GaiaDR2/> | absmag_v = +0.24<ref name=aaa361_614/> }} {{Starbox detail | mass = 2.42<ref name=aaa361_614/> | radius = {{Val|10.76|0.20|0.08}}<ref name=GaiaDR2/> | luminosity = {{Val|62.0|1.2}}<ref name=GaiaDR2/> | temperature = {{Val|4939|17|46|fmt=commas}}<ref name=GaiaDR2/> | rotational_velocity = | gravity = 3.28<ref name=alves2015/> | metal_fe = −0.34<ref name=alves2015/> | age_gyr = }} {{Starbox catalog | names = {{odlist | B=ψ<sup>1</sup> Lup | F=3 Lup | CD=−33°10631 | FK5=3237 | HD=139521 | HIP=76705 | HR=5820 | SAO=206843 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = Psi01+Lup }} {{Starbox end}}
'''Psi<sup>1</sup> Lupi''', which is [[Romanization of Greek|Latinized]] from ψ<sup>1</sup> Lupi, is a single<ref name=Eggleton2008/> [[star]] in the southern [[constellation]] of [[Lupus (constellation)|Lupus]]. It has a yellow-white hue and is faintly visible to the naked eye with an [[apparent visual magnitude]] of +4.66.<ref name=alves2000/> The star is located at a distance of approximately 207 [[light year]]s from the [[Sun]] based on [[stellar parallax|parallax]].<ref name=GaiaDR2/> It is drifting closer with a [[radial velocity]] of −23 km/s, and is predicted to come to within {{Convert|11.06|pc|ly|0|disp=out|abbr=off}} in 2.8 million years.<ref name=Anderson2012/>
This is an [[stellar evolution|evolved]] [[giant star]] with a [[stellar classification]] of G8/K0 III.<ref name=houk/> With the hydrogen exhausted at its [[stellar core|core]], the star has cooled and expanded to 11 times the [[radius of the Sun]].<ref name=GaiaDR2/> It is a [[red clump]]<ref name=alves2000/> giant, which indicates it is on the [[horizontal branch]] and is generating energy through [[stellar core|core]] [[helium fusion]]. The star has an estimated 2.4<ref name=aaa361_614/> times the [[Sun's mass]] and is radiating 62 times the [[luminosity of the Sun]] from its [[photosphere]] at an [[effective temperature]] of 4,939 K.<ref name=GaiaDR2/>
The star is surrounded by a cold [[circumstellar envelope]], hinted at by the anomaly of the small observed power of the doublet Mg II emission at 2800 [[angstrom]]. The absorption cores on the peaks of the emission profiles Mg II k and h are mainly of interstellar origin and only partly due to self-absorption in the star's chromosphere.<ref name="Gurzadian et al."/>
==See also== *[[Psi2 Lupi|ψ<sup>2</sup> Lupi]]
==References== <references>
<ref name=GaiaDR2>{{Cite Gaia DR2|6013425703029987712}}</ref>
<ref name=SIMBAD>{{cite simbad | title=psi01 Lup | access-date=2017-08-16 | postscript=. }}</ref>
<ref name=Eggleton2008>{{cite journal | title=A catalogue of multiplicity among bright stellar systems | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=869 | date=2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | arxiv=0806.2878 | bibcode=2008MNRAS.389..869E | s2cid=14878976 }}</ref>
<ref name=Anderson2012>{{cite journal | 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 | arxiv=1108.4971 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}</ref>
<ref name="Gurzadian et al.">{{cite journal | display-authors=1 | last1=Gurzadian | first1=G. A. | last2=Kondo | first2=Y. | last3=Ohanesyan | first3=J. B. | last4=Terzian | first4=Yervant | last5=Perez | first5=Mario R. | title=A cool giant with a circumstellar cloud | journal=Astrophysics and Space Science | volume=176 | issue=1 | pages=61–68 | date=1991 | bibcode=1991Ap&SS.176...61G | doi=10.1007/BF00643077 | s2cid=122673985 | url=https://zenodo.org/record/1232446 }}</ref>
<ref name=aaa361_614>{{citation | last1=Pizzolato | first1=N. | last2=Maggio | first2=A. | last3=Sciortino | first3=S. | title=Evolution of X-ray activity of 1-3 Msun late-type stars in early post-main-sequence phases | journal=Astronomy and Astrophysics | volume=361 | pages=614–628 | date=September 2000 | bibcode=2000A&A...361..614P }}</ref>
<ref name=alves2000>{{cite journal | last1=Alves | first1=David R. | title=K-Band Calibration of the Red Clump Luminosity | journal=The Astrophysical Journal | volume=539 | issue=2 | pages=732–741 | year=2000 | doi=10.1086/309278 | arxiv=astro-ph/0003329 | bibcode=2000ApJ...539..732A | s2cid=16673121 }}</ref>
<ref name=alves2015>{{cite journal | last1=Adibekyan | first1=V. Zh. | last2=Benamati | first2=L. | last3=Santos | first3=N. C. | last4=Alves | first4=S. | last5=Lovis | first5=C. | last6=Udry | first6=S. | last7=Israelian | first7=G. | last8=Sousa | first8=S. G. | last9=Tsantaki | first9=M. | last10=Mortier | first10=A. | last11=Sozzetti | first11=A. | last12=De Medeiros | first12=J. R. | display-authors=1 | title= Chemical abundances and kinematics of 257 G-, K-type field giants. Setting a base for further analysis of giant-planet properties orbiting evolved stars | journal=Monthly Notices of the Royal Astronomical Society | volume=450 | issue=2 | pages=1900 | year=2015 | doi=10.1093/mnras/stv716 | doi-access=free | arxiv=1503.08346 | bibcode=2015MNRAS.450.1900A | s2cid=58920318 }}</ref>
<ref name=houk>{{cite book | last1=Houk | first1=N. | title=Michigan Catalogue of Two-dimensional Spectral Types for the HD stars | volume=3 | year=1982 | bibcode=1982mcts.book.....H }}</ref>
</references>
{{Stars of Lupus}}
[[Category:G-type giants]] [[Category:K-type giants]] [[Category:Horizontal-branch stars]] [[Category:Lupus (constellation)]] [[Category:Bayer objects|Lupi, Psi1]] [[Category:Durchmusterung objects|CD-33 10631]] [[Category:Flamsteed objects|Lupi, 3]] [[Category:Henry Draper Catalogue objects|139521]] [[Category:Hipparcos objects|076705]] [[Category:Bright Star Catalogue objects|5820]]