{{Short description|Star in the constellation Draco}} {{Starbox begin}} {{Starbox image | image = {{Location mark |image=Draco constellation map.svg|alt=|float=center|width=280 |label=|position=right |mark=Red circle.svg|mark_width=10|mark_link=π Draconis |x=140|y=565 }} | caption = Location of π Draconis (circled in red) }} {{Starbox observe | epoch = J2000 | constell = [[Draco (constellation)|Draco]] | ra = {{RA|19|20|40.09333}}<ref name=vanLeeuwen2007/> | dec = {{DEC|+65|42|52.3095}}<ref name=vanLeeuwen2007/> | appmag_v = 4.59<ref name=Johnson1966/> }} {{Starbox character | class = A2 IIIs<ref name=Royer2002/><ref name=Eggleton2008/> | b-v = +0.02<ref name=Johnson1966/> | u-b = +0.06<ref name=Johnson1966/> | r-i = | variable = }} {{Starbox astrometry | radial_v = {{Val|−28.1|1.1}}<ref name=Gontcharov2006/> | prop_mo_ra = +15.09<ref name=vanLeeuwen2007/> | prop_mo_dec = +41.12<ref name=vanLeeuwen2007/> | parallax = 14.25 | p_error = 0.12 | parallax_footnote = <ref name=vanLeeuwen2007/> | absmag_v = +0.37<ref name=Anderson2012/> }} {{Starbox detail | source = | mass = 2.70<ref name=DeRosa2014/> | radius = 3.2<ref name=lang2006/> | luminosity = 60<ref name=mcdonald2012/> | temperature = 9,125<ref name=Yuece2014/> | gravity = 3.80<ref name=Yuece2014/> | metal_fe = 0.42<ref name=Anderson2012/> | rotational_velocity = {{Val|26|1}}<ref name=Royer2002/> | age_myr = 350<ref name=DeRosa2014/> }} {{Starbox catalog | names = {{odlist|B=π Dra | F=58 Dra | BD=+65°1345 | FK5=3547 | HD=182564 | HIP=95081 | HR=7371 | SAO=18299 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad = pi.+Dra }} {{Starbox end}} '''Pi Draconis''', [[Latinisation of names|Latinized]] from '''π Draconis''', is a solitary<ref name=DeRosa2014/><ref name=Eggleton2008/> [[star]] in the northern [[circumpolar constellation]] of [[Draco (constellation)|Draco]]. It is visible to the naked eye with an [[apparent visual magnitude]] of 4.59.<ref name=Johnson1966/> Based upon an annual [[stellar parallax|parallax shift]] of 14.25 [[milliarcsecond|mas]] as measured from Earth,<ref name=vanLeeuwen2007/> it is located around 229 [[light year]]s from the [[Sun]]. At that distance, the visual magnitude is diminished by an [[extinction (astronomy)|extinction factor]] of {{Val|0.063|0.10}} due to [[interstellar dust]].<ref name=vanBelle2009/>
With an age of 350 million years, this is an [[A-type star]] of [[stellar classification]] A2 IIIs,<ref name=Royer2002/><ref name=Eggleton2008/> where the [[luminosity class]] of III typically indicates an [[stellar evolution|evolved]] [[giant star]] and the 's' means the [[spectrum]] displays sharp [[absorption line]]s. It is a candidate [[Am star]],<ref name=Yuece2014/> meaning there are some [[Chemically peculiar star|chemical peculiarities]]. The measured [[angular size]] is {{Val|0.427|0.062|u=arc seconds}}.<ref name=vanBelle2009/> At the estimated distance of Pi Draconis, this yields a physical size of about 3.2 times the [[Solar radius|radius of the Sun]].<ref name=lang2006/> It has about 2.70<ref name=DeRosa2014/> times the [[mass of the Sun]] and is radiating 60<ref name=mcdonald2012/> times the [[solar luminosity]] from its [[photosphere]] at an [[effective temperature]] of 9,125 K.<ref name=Yuece2014/>
==References== <references> <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=Gontcharov2006>{{citation | last1=Gontcharov | first1=G. A. | title=Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system | journal=Astronomy Letters | volume=32| issue=11 | pages=759–771| date=November 2006 | doi=10.1134/S1063773706110065 | bibcode=2006AstL...32..759G | arxiv=1606.08053 | s2cid=119231169 | 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=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 | pages=343–357 | year=2012 | issue=1 | bibcode=2012MNRAS.427..343M | doi=10.1111/j.1365-2966.2012.21873.x | doi-access=free | arxiv=1208.2037 | s2cid=118665352 | postscript=. }}</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=vanBelle2009>{{citation | title=Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars | last1=van Belle | first1=Gerard T. | last2=von Braun | first2=Kaspar | journal=The Astrophysical Journal | volume=694 | issue=2 | pages=1085–1098 | date=2009 | arxiv=0901.1206 | postscript=. | bibcode=2009ApJ...694.1085V | doi=10.1088/0004-637X/694/2/1085 | s2cid=18370219 }}</ref>
<ref name=lang2006>{{citation | first1=Kenneth R. | last1=Lang | postscript=. | title=Astrophysical formulae | volume=1 | series=Astronomy and astrophysics library | edition=3rd | publisher=[[Birkhäuser]] | date=2006 | isbn=3-540-29692-1 | url=https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41 }} The radius (R<sub>*</sub>) is given by: :<math>\begin{align} 2\cdot R_* & = \frac{(70.2\cdot 0.427\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\ & \approx 6.4\cdot R_{\bigodot} \end{align}</math></ref>
<ref name=Yuece2014>{{citation | postscript=. | title=Elemental Abundance Analyses with DAO Spectrograms. XXXIV. A Three-Dimensional Graphical Examination of the Elemental Abundances of the Mercury-Manganese and Metallic-Line Stars | last1=Yüce | first1=Kutluay | last2=Adelman | first2=Saul J. | journal=Publications of the Astronomical Society of the Pacific | volume=126 | issue=938 | pages=345 | date=April 2014 | doi=10.1086/676335 | bibcode=2014PASP..126..345Y | doi-access=free }}</ref>
<ref name=DeRosa2014>{{citation | display-authors=1 | last1=De Rosa | first1=R. J. | last2=Patience | first2=J. | last3=Wilson | first3=P. A. | last4=Schneider | first4=A. | last5=Wiktorowicz | first5=S. J. | last6=Vigan | first6=A. | last7=Marois | first7=C. | last8=Song | first8=I. | last9=Macintosh | first9=B. | last10=Graham | first10=J. R. | last11=Doyon | first11=R. | last12=Bessell | first12=M. S. | last13=Thomas | first13=S. | last14=Lai | first14=O. | title=The VAST Survey - III. The multiplicity of A-type stars within 75 pc | journal=Monthly Notices of the Royal Astronomical Society | volume=437 | issue=2 | pages=1216–1240 | date=January 2014 | doi=10.1093/mnras/stt1932 | doi-access=free | bibcode=2014MNRAS.437.1216D | arxiv=1311.7141 | postscript=. }}</ref>
<ref name=Royer2002>{{citation | display-authors=1 | last1=Royer | first1=F. | last2=Grenier | first2=S. | last3=Baylac | first3=M.-O. | last4=Gómez | first4=A. E. | last5=Zorec | first5=J. | title=Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i | journal=Astronomy and Astrophysics | volume=393 | pages=897–911 | date=October 2002 | doi=10.1051/0004-6361:20020943 | bibcode=2002A&A...393..897R | arxiv=astro-ph/0205255 | s2cid=14070763 | postscript=. }}</ref>
<ref name=Johnson1966>{{citation | display-authors=1 | last1=Johnson | first1=H. L. | last2=Iriarte | first2=B. | last3=Mitchell | first3=R. I. | last4=Wisniewskj | first4=W. Z. | title=UBVRIJKL photometry of the bright stars | journal=Communications of the Lunar and Planetary Laboratory | volume=4 | issue=99 | year=1966 | page=99 | bibcode=1966CoLPL...4...99J | postscript=. }}</ref>
<ref name=SIMBAD>{{cite simbad | title=pi. Dra | access-date=2017-05-30 }}</ref> </references>
{{Stars of Draco|state=collapsed}}
[[Category:A-type giants]] [[Category:Am stars]] [[Category:Draco (constellation)]] [[Category:Bayer objects|Draconis, Pi]] [[Category:Durchmusterung objects|BD+65 1345]] [[Category:Flamsteed objects|Draconis, 58]] [[Category:Henry Draper Catalogue objects|182564]] [[Category:Hipparcos objects|095081]] [[Category:Bright Star Catalogue objects|7371]] [[Category:Population I stars]]