Pi Coronae Borealis

Pi Coronae Borealis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Corona Borealis
Right ascension 15h 43m 59.29973s[1]
Declination +32° 30′ 56.9047″[1]
Apparent magnitude (V) 5.578[2]
Characteristics
Spectral type G9 III:[2]
B−V color index 1.074[3]
Astrometry
Radial velocity (Rv)−4.94±0.51[3] km/s
Proper motion (μ) RA: −29.92[1] mas/yr
Dec.: −8.85[1] mas/yr
Parallax (π)13.40 ± 0.21 mas[1]
Distance243 ± 4 ly
(75 ± 1 pc)
Absolute magnitude (MV)+1.21[4]
Details[3]
Mass1.61[2] M☉
Radius10 R☉
Luminosity39 L☉
Surface gravity (log g)2.7 cgs
Temperature4,667±5 K
Metallicity [Fe/H]−0.15 dex
Rotational velocity (v sin i)3.5 km/s
Age4.6[2] Gyr
Other designations
π CrB, 9 CrB, BD+32° 2621, HD 140716, HIP 77048, HR 5855, SAO 64870[5]
Database references
SIMBADdata

Pi Coronae Borealis, Latinized from π Coronae Borealis, is a solitary,[6] orange-hued star in the northern constellation of Corona Borealis. Its apparent magnitude is 5.58,[2] which is bright enough to be faintly visible to the naked eye. Based upon an annual parallax shift of 13.40 mas as measured from Earth, it is located about 243 light years from the Sun. The star is moving closer to the Sun with a radial velocity of −5 km/s.[3] It is most likely (98% chance) a member of the thin disk population.[7]

This is an evolved G-type giant star with a stellar classification of G9 III:, where the ':' indicates some uncertainty about the classification. (Bartkevicius and Lazauskaite (1997) classify it as K0 III.)[8] The star has 1.61[2] times the mass of the Sun and has expanded to about 10 times the Sun's radius. The abundance of iron is lower than in the Sun: the star is considered metal deficient.[8] It is around 4.6[2] billion years old and is radiating 39 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,667 K.[3]

  1. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d e f g Cite error: The named reference luck2015 was invoked but never defined (see the help page).
  3. ^ a b c d e Cite error: The named reference Massarotti2008 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Soubiran2008 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Bartkevicius1997 was invoked but never defined (see the help page).