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Star in the constellation Orion
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]
References
^
a
b
c
d
e
f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics , 474 (2): 653–664,
arXiv :
0708.1752 ,
Bibcode :
2007A&A...474..653V ,
doi :
10.1051/0004-6361:20078357 ,
S2CID
18759600 .
^
a
b
c
d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory , 4 (99): 99,
Bibcode :
1966CoLPL...4...99J .
^
a
b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal , 74 : 375–406,
Bibcode :
1969AJ.....74..375C ,
doi :
10.1086/110819 .
^ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Washington , Carnegie Institute of Washington, D.C.,
Bibcode :
1953GCRV..C......0W .
^
a
b
c Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics , 542 : A116,
arXiv :
1204.2459 ,
Bibcode :
2012A&A...542A.116A ,
doi :
10.1051/0004-6361/201118724 ,
S2CID
53666672 .
^ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics", Astronomy and Astrophysics , 367 (2): 521–524,
arXiv :
astro-ph/0012289 ,
Bibcode :
2001A&A...367..521P ,
doi :
10.1051/0004-6361:20000451 ,
S2CID
425754 .
^
a
b McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society , 427 (1): 343–57,
arXiv :
1208.2037 ,
Bibcode :
2012MNRAS.427..343M ,
doi :
10.1111/j.1365-2966.2012.21873.x ,
S2CID
118665352 .
^
a
b
c
d Wu, Yue; et al. (January 2011), "Coudé-feed stellar spectral library - atmospheric parameters", Astronomy and Astrophysics , 525 : A71,
arXiv :
1009.1491 ,
Bibcode :
2011A&A...525A..71W ,
doi :
10.1051/0004-6361/201015014 ,
S2CID
53480665 .
^
"pi.02 Ori" .
SIMBAD .
Centre de données astronomiques de Strasbourg . Retrieved 2016-11-16 .
^ Hoffleit, Dorrit (1964), Catalogue of Bright Stars (3rd ed.), New Haven, Conn: Yale University Observatory,
Bibcode :
1964cbs..book.....H .
^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems",
Monthly Notices of the Royal Astronomical Society , 389 (2): 869–879,
arXiv :
0806.2878 ,
Bibcode :
2008MNRAS.389..869E ,
doi :
10.1111/j.1365-2966.2008.13596.x ,
S2CID
14878976 .
^ Belle, G. T. (2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review , 20 (1): 51,
arXiv :
1204.2572 ,
Bibcode :
2012A&ARv..20...51V ,
doi :
10.1007/s00159-012-0051-2 ,
S2CID
119273474 .