Astronomy:Omicron Arietis

From HandWiki
Short description: Star in the constellation Aries
Omicron Arietis
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aries
Right ascension  02h 44m 32.97317s[1]
Declination +15° 18′ 42.7085″[1]
Apparent magnitude (V) +5.78[2]
Characteristics
Spectral type B9 Vn[3]
U−B color index −0.21[4]
B−V color index −0.01[4]
Astrometry
Radial velocity (Rv)−2.4±3.3[5] km/s
Proper motion (μ) RA: +3.25[1] mas/yr
Dec.: −14.87[1] mas/yr
Parallax (π)5.49 ± 0.32[1] mas
Distance590 ± 30 ly
(180 ± 10 pc)
Absolute magnitude (MV)−0.51[6]
Details
Mass3.45±0.09[7] M
Radius3.1[8] R
Luminosity248[7] L
Temperature10,715[7] K
Rotational velocity (v sin i)225[9] km/s
Age286[10] Myr
Other designations
ο Ari, 37 Arietis, BD+14° 457, HD 17036, HIP 12803, HR 809, SAO 93082[11]
Database references
SIMBADdata

Omicron Arietis, Latinised from ο Arietis, is the Bayer designation for a single,[2] blue-white-hued star in the northern constellation of Aries. It has an apparent visual magnitude of +5.78,[2] which means it is dimly visible to the naked eye. Based upon an annual parallax shift of 5.49 mas as seen from Earth,[1] it is located roughly 590 light-years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.22 due to interstellar dust.[10]

This is a B-type main-sequence star with a stellar classification of B9 Vn.[3] The 'n' suffix indicates that it has nebulous absorption lines in its spectrum, which are caused by the Doppler effect and rapid rotation. Indeed, it has a projected rotational velocity of 225 km/s.[9] The star has an estimated 3.45[7] times the mass of the Sun and about 3.1[8] times the Sun's radius. It is radiating energy from its photosphere at 248 times the Sun's luminosity with an effective temperature of 10,715 K.[7]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  3. 3.0 3.1 Cowley, A. (November 1972), "Spectral classification of the bright B8 stars", Astronomical Journal 77: 750–755, doi:10.1086/111348, Bibcode1972AJ.....77..750C. 
  4. 4.0 4.1 Crawford, D. L. (February 1963), "U, b, v, and Hβ Photometry for the Bright B8- and B9-TYPE Stars", Astrophysical Journal 137: 530, doi:10.1086/147526, Bibcode1963ApJ...137..530C. 
  5. de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics 546: 14, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  6. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  7. 7.0 7.1 7.2 7.3 7.4 Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics 537: A120, doi:10.1051/0004-6361/201117691, Bibcode2012A&A...537A.120Z. 
  8. 8.0 8.1 Pasinetti Fracassini, L. E. et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics 367: 5211–524, doi:10.1051/0004-6361:20000451, Bibcode2001A&A...367..521P. 
  9. 9.0 9.1 Royer, F. et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics 463 (2): 671–682, doi:10.1051/0004-6361:20065224, Bibcode2007A&A...463..671R. 
  10. 10.0 10.1 Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode2012AstL...38..694G. 
  11. "omi Ari". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=omi+Ari. 

External links