Pi2 Orionis

For other stars with this Bayer designation, see Pi Orionis.
π2 Orionis
Location of π2 Orionis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Orion
Right ascension 04h 50m 36.72298s[1]
Declination +08° 54′ 00.6493″[1]
Apparent magnitude (V) 4.35[2]
Characteristics
Spectral type A1 Vn[3]
U−B color index +0.03[2]
B−V color index +0.01[2]
Astrometry
Radial velocity (Rv)24[4] km/s
Proper motion (μ) RA: +1.41[1] mas/yr
Dec.: −29.91[1] mas/yr
Parallax (π)14.53 ± 0.38 mas[1]
Distance224 ± 6 ly
(69 ± 2 pc)
Absolute magnitude (MV)0.48[5]
Details
Radius2.7[6] R☉
Luminosity70[7] L☉
Surface gravity (log g)4.00±0.05[8] cgs
Temperature9,457±128[8] K
Metallicity [Fe/H]−0.20±0.10[8] dex
Rotational velocity (v sin i)261.4±13.5[5] km/s
Other designations
π2 Ori, 2 Orionis, BD+08°777, HD 30739, HIP 22509, HR 1544, SAO 112124[9]
Database references
SIMBADdata

Pi2 Orionis (π2 Ori, π2 Orionis) is the Bayer designation for a solitary star in the equatorial constellation of Orion. Although the Bright Star Catalogue lists this as a spectroscopic binary star system,[10] this does not appear to be the case.[11] It is visible to the naked eye with an apparent visual magnitude of 4.35.[2] Based upon an annual parallax shift of 14.53 mas,[1] it is located roughly 224 light-years away from the Sun.

This is an A-type main-sequence star with a stellar classification of A1 Vn,[3] where the 'n' indicates broad absorption lines due to rotation. It is spinning rapidly with a projected rotational velocity of 261.4 km/s.[5] This is giving the star an oblate shape with an equatorial bulge that is 13% larger than the polar radius.[12] It is shining with 70[7] times the solar luminosity from its outer atmosphere at an effective temperature of 9,457 K.[8]

  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 Cite error: The named reference Cowley1969 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Wilson1953 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference vonEiff2012 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Wu2011 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Hoffliet1964 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference belle2012 was invoked but never defined (see the help page).