Pi Draconis
Star in the constellation Draco
From Wikipedia, the free encyclopedia
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]
 | |
| 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 |
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]
