22 Scorpii (i Scorpii) is a single[7] star in the southern zodiac constellation of Scorpius, about one degree from Antares. It is faintly visible to the naked eye with an apparent visual magnitude of 4.78.[2] The distance to this star is estimated to be around 410 light years, as derived from its annual parallax shift of 7.89±0.24 mas.[1] The star is embedded in, or adjacent to, the diffuse nebulous cloud IC 4605 located in the western regions of the Rho Ophiuchi cloud complex.[8]

22 Scorpii
Observation data
Epoch J2000      Equinox J2000
Constellation Scorpius
Right ascension 16h 30m 12.47514s[1]
Declination −25° 06′ 54.8043″[1]
Apparent magnitude (V) 4.78[2]
Characteristics
Spectral type B3 V[3]
Astrometry
Proper motion (μ) RA: −4.45[1] mas/yr
Dec.: −26.33[1] mas/yr
Parallax (π)7.89 ± 0.24 mas[1]
Distance410 ± 10 ly
(127 ± 4 pc)
Absolute magnitude (MV)−0.72[4]
Details
Mass6.1±0.1[5] M
Luminosity334.57[4] L
Temperature19,600[2] K
Rotational velocity (v sin i)169±4[2] km/s
Age10.5±2.1[5] Myr
Other designations
i Sco, 22 Sco, CD−24°12695, HD 148605, HIP 80815, HR 6141, SAO 184429[6]
Database references
SIMBADdata
22 Scorpii in the IC 4605 reflection nebula, one of a collection of diffuse and dark nebulae in the Rho Ophiuchi cloud complex
22 Scorpii in the IC 4605 reflection nebula, one of a collection of diffuse and dark nebulae in the Rho Ophiuchi cloud complex.

22 Scorpii is a B-type main-sequence star with a stellar classification of B3 V.[3] It is ten[5] million years old and has a high rate of spin with a projected rotational velocity of 169 km/s.[2] The star has about six[5] times the mass of the Sun and is radiating 335[4] times the Sun's luminosity from its photosphere at an effective temperature of 19,600 K.[2]

References

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  1. ^ 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.
  2. ^ a b c d e f Bragança, G. A.; et al. (November 2012), "Projected Rotational Velocities and Stellar Characterization of 350 B Stars in the Nearby Galactic Disk", The Astronomical Journal, 144 (5): 10, arXiv:1208.1674, Bibcode:2012AJ....144..130B, doi:10.1088/0004-6256/144/5/130, S2CID 118868235, 130.
  3. ^ a b Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
  4. ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  5. ^ a b c d Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
  6. ^ "22 Sco". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-03-16.
  7. ^ 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.
  8. ^ Padgett, Deborah L.; et al. (January 2008), "The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. VII. Ophiuchus Observed with MIPS", The Astrophysical Journal, 672 (2): 1013–1037, arXiv:0709.3492, Bibcode:2008ApJ...672.1013P, doi:10.1086/523883, S2CID 12396730, 1013–1037.
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