Pi Draconis

Pi Draconis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
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]
Distance229 ± 2 ly
(70.2 ± 0.6 pc)
Absolute magnitude (MV)+0.37[6]
Details
Mass2.70[7] M☉
Radius3.2[8] R☉
Luminosity60[9] L☉
Surface gravity (log g)3.80[10] cgs
Temperature9,125[10] K
Metallicity [Fe/H]0.42[6] dex
Rotational velocity (v sin i)26±1[3] km/s
Age350[7] Myr
Other designations
π Dra, 58 Dra, BD+65° 1345, FK5 3547, HD 182564, HIP 95081, HR 7371, SAO 18299[11]
Database references
SIMBADdata

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

With an age of 350 million years, this is an A-type star of stellar classification A2 IIIs,[3][4] where the luminosity class of III typically indicates an evolved giant star and the 's' means the spectrum displays sharp absorption lines. It is a candidate Am star,[10] meaning there are some chemical peculiarities. The measured 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.[8] It has about 2.70[7] times the mass of the Sun and is radiating 60[9] times the solar luminosity from its photosphere at an effective temperature of 9,125 K.[10]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Royer2002 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference DeRosa2014 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference lang2006 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference mcdonald2012 was invoked but never defined (see the help page).
  10. ^ a b c d Cite error: The named reference Yuece2014 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ a b Cite error: The named reference vanBelle2009 was invoked but never defined (see the help page).