22 Scorpii

This article is about i Scorpii. Not to be confused with ι Scorpii.
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 (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 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]

  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 e f Cite error: The named reference Braganca2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference houk1978 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  5. ^ a b c d Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Padgett2008 was invoked but never defined (see the help page).