# Pi Draconis

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Pi_Draconis
> Markdown URL: https://mediated.wiki/source/Pi_Draconis.md
> Source: https://en.wikipedia.org/wiki/Pi_Draconis
> Source revision: 1336037401
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Star in the constellation Draco

Pi Draconis Location of π Draconis (circled in red) Observation data Epoch J2000 Equinox J2000 Constellation Draco Right ascension 19h 20m 40.09333s[1] Declination +65° 42′ 52.3095″[1] Apparent magnitude (V) 4.59[2] Characteristics Spectral type A2 IIIs[3][4] U−B color index +0.06[2] B−V color index +0.02[2] Astrometry Radial velocity (Rv) −28.1±1.1[5] km/s Proper motion (μ) RA: +15.09[1] mas/yr Dec.: +41.12[1] mas/yr Parallax (π) 14.25±0.12 mas[1] Distance 229 ± 2 ly (70.2 ± 0.6 pc) Absolute magnitude (MV) +0.37[6] Details Mass 2.70[7] M☉ Radius 3.2[8] R☉ Luminosity 60[9] L☉ Surface gravity (log g) 3.80[10] cgs Temperature 9,125[10] K Metallicity [Fe/H] 0.42[6] dex Rotational velocity (v sin i) 26±1[3] km/s Age 350[7] Myr Other designations π Dra, 58 Dra, BD+65°1345, FK5 3547, HD 182564, HIP 95081, HR 7371, SAO 18299[11] Database references SIMBAD data

**Pi Draconis**, [Latinized](/source/Latinisation_of_names) from **π Draconis**, is a solitary[7][4] [star](/source/Star) in the northern [circumpolar constellation](/source/Circumpolar_constellation) of [Draco](/source/Draco_(constellation)). It is visible to the naked eye with an [apparent visual magnitude](/source/Apparent_visual_magnitude) of 4.59.[2] Based upon an annual [parallax shift](/source/Stellar_parallax) of 14.25 [mas](/source/Milliarcsecond) as measured from Earth,[1] it is located around 229 [light years](/source/Light_year) from the [Sun](/source/Sun). At that distance, the visual magnitude is diminished by an [extinction factor](/source/Extinction_(astronomy)) of 0.063±0.10 due to [interstellar dust](/source/Interstellar_dust).[12]

With an age of 350 million years, this is an [A-type star](/source/A-type_star) of [stellar classification](/source/Stellar_classification) A2 IIIs,[3][4] where the [luminosity class](/source/Luminosity_class) of III typically indicates an [evolved](/source/Stellar_evolution) [giant star](/source/Giant_star) and the 's' means the [spectrum](/source/Spectrum) displays sharp [absorption lines](/source/Absorption_line). It is a candidate [Am star](/source/Am_star),[10] meaning there are some [chemical peculiarities](/source/Chemically_peculiar_star). The measured [angular size](/source/Angular_size) is 0.427±0.062 arc seconds.[12] At the estimated distance of Pi Draconis, this yields a physical size of about 3.2 times the [radius of the Sun](/source/Solar_radius).[8] It has about 2.70[7] times the [mass of the Sun](/source/Mass_of_the_Sun) and is radiating 60[9] times the [solar luminosity](/source/Solar_luminosity) from its [photosphere](/source/Photosphere) at an [effective temperature](/source/Effective_temperature) of 9,125 K.[10]

## References

1. ^ [***a***](#cite_ref-vanLeeuwen2007_1-0) [***b***](#cite_ref-vanLeeuwen2007_1-1) [***c***](#cite_ref-vanLeeuwen2007_1-2) [***d***](#cite_ref-vanLeeuwen2007_1-3) [***e***](#cite_ref-vanLeeuwen2007_1-4) [***f***](#cite_ref-vanLeeuwen2007_1-5) van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", *Astronomy and Astrophysics*, **474** (2): 653–664, [arXiv](/source/ArXiv_(identifier)):[0708.1752](https://arxiv.org/abs/0708.1752), [Bibcode](/source/Bibcode_(identifier)):[2007A&A...474..653V](https://ui.adsabs.harvard.edu/abs/2007A&A...474..653V), [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20078357](https://doi.org/10.1051%2F0004-6361%3A20078357), [S2CID](/source/S2CID_(identifier)) [18759600](https://api.semanticscholar.org/CorpusID:18759600).

1. ^ [***a***](#cite_ref-Johnson1966_2-0) [***b***](#cite_ref-Johnson1966_2-1) [***c***](#cite_ref-Johnson1966_2-2) [***d***](#cite_ref-Johnson1966_2-3) Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", *Communications of the Lunar and Planetary Laboratory*, **4** (99): 99, [Bibcode](/source/Bibcode_(identifier)):[1966CoLPL...4...99J](https://ui.adsabs.harvard.edu/abs/1966CoLPL...4...99J).

1. ^ [***a***](#cite_ref-Royer2002_3-0) [***b***](#cite_ref-Royer2002_3-1) [***c***](#cite_ref-Royer2002_3-2) Royer, F.; et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", *Astronomy and Astrophysics*, **393**: 897–911, [arXiv](/source/ArXiv_(identifier)):[astro-ph/0205255](https://arxiv.org/abs/astro-ph/0205255), [Bibcode](/source/Bibcode_(identifier)):[2002A&A...393..897R](https://ui.adsabs.harvard.edu/abs/2002A&A...393..897R), [doi](/source/Doi_(identifier)):[10.1051/0004-6361:20020943](https://doi.org/10.1051%2F0004-6361%3A20020943), [S2CID](/source/S2CID_(identifier)) [14070763](https://api.semanticscholar.org/CorpusID:14070763).

1. ^ [***a***](#cite_ref-Eggleton2008_4-0) [***b***](#cite_ref-Eggleton2008_4-1) [***c***](#cite_ref-Eggleton2008_4-2) Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", *[Monthly Notices of the Royal Astronomical Society](/source/Monthly_Notices_of_the_Royal_Astronomical_Society)*, **389** (2): 869–879, [arXiv](/source/ArXiv_(identifier)):[0806.2878](https://arxiv.org/abs/0806.2878), [Bibcode](/source/Bibcode_(identifier)):[2008MNRAS.389..869E](https://ui.adsabs.harvard.edu/abs/2008MNRAS.389..869E), [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2008.13596.x](https://doi.org/10.1111%2Fj.1365-2966.2008.13596.x), [S2CID](/source/S2CID_(identifier)) [14878976](https://api.semanticscholar.org/CorpusID:14878976).

1. **[^](#cite_ref-Gontcharov2006_5-0)** Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", *Astronomy Letters*, **32** (11): 759–771, [arXiv](/source/ArXiv_(identifier)):[1606.08053](https://arxiv.org/abs/1606.08053), [Bibcode](/source/Bibcode_(identifier)):[2006AstL...32..759G](https://ui.adsabs.harvard.edu/abs/2006AstL...32..759G), [doi](/source/Doi_(identifier)):[10.1134/S1063773706110065](https://doi.org/10.1134%2FS1063773706110065), [S2CID](/source/S2CID_(identifier)) [119231169](https://api.semanticscholar.org/CorpusID:119231169).

1. ^ [***a***](#cite_ref-Anderson2012_6-0) [***b***](#cite_ref-Anderson2012_6-1) Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", *Astronomy Letters*, **38** (5): 331, [arXiv](/source/ArXiv_(identifier)):[1108.4971](https://arxiv.org/abs/1108.4971), [Bibcode](/source/Bibcode_(identifier)):[2012AstL...38..331A](https://ui.adsabs.harvard.edu/abs/2012AstL...38..331A), [doi](/source/Doi_(identifier)):[10.1134/S1063773712050015](https://doi.org/10.1134%2FS1063773712050015), [S2CID](/source/S2CID_(identifier)) [119257644](https://api.semanticscholar.org/CorpusID:119257644).

1. ^ [***a***](#cite_ref-DeRosa2014_7-0) [***b***](#cite_ref-DeRosa2014_7-1) [***c***](#cite_ref-DeRosa2014_7-2) [***d***](#cite_ref-DeRosa2014_7-3) De Rosa, R. J.; et al. (January 2014), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc", *Monthly Notices of the Royal Astronomical Society*, **437** (2): 1216–1240, [arXiv](/source/ArXiv_(identifier)):[1311.7141](https://arxiv.org/abs/1311.7141), [Bibcode](/source/Bibcode_(identifier)):[2014MNRAS.437.1216D](https://ui.adsabs.harvard.edu/abs/2014MNRAS.437.1216D), [doi](/source/Doi_(identifier)):[10.1093/mnras/stt1932](https://doi.org/10.1093%2Fmnras%2Fstt1932).

1. ^ [***a***](#cite_ref-lang2006_8-0) [***b***](#cite_ref-lang2006_8-1) Lang, Kenneth R. (2006), [*Astrophysical formulae*](https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41), Astronomy and astrophysics library, vol. 1 (3rd ed.), [Birkhäuser](/source/Birkh%C3%A4user), [ISBN](/source/ISBN_(identifier)) [3-540-29692-1](https://en.wikipedia.org/wiki/Special:BookSources/3-540-29692-1). The radius (R*) is given by: 1. 2 ⋅ R ∗ = ( 70.2 ⋅ 0.427 ⋅ 10 − 3 ) AU 0.0046491 AU / R ⨀ ≈ 6.4 ⋅ R ⨀ {\displaystyle {\begin{aligned}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{aligned}}}

1. ^ [***a***](#cite_ref-mcdonald2012_9-0) [***b***](#cite_ref-mcdonald2012_9-1) McDonald, I.; et al. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", *Monthly Notices of the Royal Astronomical Society*, **427** (1): 343–357, [arXiv](/source/ArXiv_(identifier)):[1208.2037](https://arxiv.org/abs/1208.2037), [Bibcode](/source/Bibcode_(identifier)):[2012MNRAS.427..343M](https://ui.adsabs.harvard.edu/abs/2012MNRAS.427..343M), [doi](/source/Doi_(identifier)):[10.1111/j.1365-2966.2012.21873.x](https://doi.org/10.1111%2Fj.1365-2966.2012.21873.x), [S2CID](/source/S2CID_(identifier)) [118665352](https://api.semanticscholar.org/CorpusID:118665352).

1. ^ [***a***](#cite_ref-Yuece2014_10-0) [***b***](#cite_ref-Yuece2014_10-1) [***c***](#cite_ref-Yuece2014_10-2) [***d***](#cite_ref-Yuece2014_10-3) Yüce, Kutluay; Adelman, Saul J. (April 2014), "Elemental Abundance Analyses with DAO Spectrograms. XXXIV. A Three-Dimensional Graphical Examination of the Elemental Abundances of the Mercury-Manganese and Metallic-Line Stars", *Publications of the Astronomical Society of the Pacific*, **126** (938): 345, [Bibcode](/source/Bibcode_(identifier)):[2014PASP..126..345Y](https://ui.adsabs.harvard.edu/abs/2014PASP..126..345Y), [doi](/source/Doi_(identifier)):[10.1086/676335](https://doi.org/10.1086%2F676335).

1. **[^](#cite_ref-SIMBAD_11-0)** ["pi. Dra"](http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=pi.+Dra). *[SIMBAD](/source/SIMBAD)*. [Centre de données astronomiques de Strasbourg](/source/Centre_de_donn%C3%A9es_astronomiques_de_Strasbourg). Retrieved 2017-05-30.

1. ^ [***a***](#cite_ref-vanBelle2009_12-0) [***b***](#cite_ref-vanBelle2009_12-1) van Belle, Gerard T.; von Braun, Kaspar (2009), "Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars", *The Astrophysical Journal*, **694** (2): 1085–1098, [arXiv](/source/ArXiv_(identifier)):[0901.1206](https://arxiv.org/abs/0901.1206), [Bibcode](/source/Bibcode_(identifier)):[2009ApJ...694.1085V](https://ui.adsabs.harvard.edu/abs/2009ApJ...694.1085V), [doi](/source/Doi_(identifier)):[10.1088/0004-637X/694/2/1085](https://doi.org/10.1088%2F0004-637X%2F694%2F2%2F1085), [S2CID](/source/S2CID_(identifier)) [18370219](https://api.semanticscholar.org/CorpusID:18370219).

v t e Constellation of Draco List of stars in Draco Draco in Chinese astronomy Stars Bayer α (Thuban) β (Rastaban) γ (Eltanin) δ (Altais) ε (Tyl) ζ (Aldhibah) η (Athebyne) θ ι (Edasich) κ λ (Giausar) μ (Alrakis) ν (Kuma) ξ (Grumium) ο π ρ σ (Alsafi) τ υ φ χ ψ1 (Dziban) ψ2 ω Flamsteed 4 6 7 (Tianyi) 8 (Taiyi) 10 (i) 15 (A) 18 (g) 19 (h) 26 36 39 (b) 42 (Fafnir) 45 (d) 50 59 64 (e) 68 Variable TW YY AG BY CL CM CX DO EK HP V581 HR 3751 4126 4934 5811 6237 6518 6618 (Alruba) 6817 7137 7783 HD 109246 (Funi) 101364 128717 147379 156279 158259 176693 191939 Other 2MASS 1237+6526 2MASS J17554042+6551277 G 240-72 GD 356 Gliese 420 Gliese 625 Gliese 687 GRW +70 8247 Kepler-4 Kepler-10 Kepler-12 Kepler-90 Kepler-296 KOI-256 LP 71-82 Qatar-1 SDSS J1240+6710 Struve 2398 TOI-1136 WD 1856+534 WISE 1647+5632 WISE 1841+7000 Exoplanets HD 139357 b HD 167042 b ι Dra b (Hypatia) Kepler-4b Kepler-10b c Kepler-12b Kepler-90e f g h i Kepler-296b c d e f TOI-1452 b TrES-2b Star clusters LAMOST 1 Nebulae Cat's Eye Nebula NGC 6742 Galaxies NGC 3147 3197 3735 4121 4125 4221 4236 4319 4331 4332 4363 4441 4513 4545 4589 5678 5777 5866 5866B 5879 5905 5907 5949 5963 5965 5982 5985 6090 6248 6285 6286 6338 6340 6365 6373 6394 6412 6503 6505 6566 6621 6622 6670 6676 6786 6789 Other 1ES 1927+654 1ES 1959+650 3C 249.1 3C 305 3C 319 3C 343 3C 343.1 3C 351 3C 356 3C 371 3C 380 3C 390.3 3C 401 4C +72.26 4C 73.08 8C 1241+735 Abell 2218 BCG Bean galaxy Beaver galaxy BZQ J1727+5510 Draco Dwarf Draco II GB 1508+5714 Goldfish galaxy H1821+643 HFLS3 IERS B1946+708 IRAS F17179+5444 IRAS 18580+6527 J120011.1+680924.8 KKR 25 Markarian 817 Markarian 876 Original TRG PGC 39058 Porphyrion QSO B1823+568 RGZ J172749.5+534647 S5 1803+784 S5 2007+777 SDSS J1715+6008 Tadpole Galaxy UGC 9391 UGC 9405 UGC 11241 UGC 11411 WISEA J145223.62+611707.5 WN B1851+5707 Galaxy clusters Abell 2218 CL1358+62 Draco Supercluster NGC 5866 Group Astronomical events SN 2003jb SN 2005B SN 2016aps Swift J1644+57 Category

---
Adapted from the Wikipedia article [Pi Draconis](https://en.wikipedia.org/wiki/Pi_Draconis) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Pi_Draconis?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.