22 Scorpii
Star in the constellation Scorpius
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22 Scorpii (i Scorpii) is a single[8] 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.[3] The distance to this star is estimated to be around 411 light years, as derived from its annual parallax shift of 7.9±0.2 mas. 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.[9]
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scorpius[1] |
| Right ascension | 16h 30m 12.47527s[2] |
| Declination | −25° 06′ 54.7966″[2] |
| Apparent magnitude (V) | 4.78[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | B3 V[4] |
| Astrometry | |
| Proper motion (μ) | RA: −4.192[2] mas/yr Dec.: −26.975[2] mas/yr |
| Parallax (π) | 7.9402±0.1848 mas[2] |
| Distance | 411 ± 10 ly (126 ± 3 pc) |
| Absolute magnitude (MV) | −0.72[1] |
| Details | |
| Mass | 4.4[5] M☉ |
| Radius | 3.4[2] R☉ |
| Luminosity | 601[5] L☉ |
| Surface gravity (log g) | 4.5[6] cgs |
| Temperature | 16,683[5] K |
| Metallicity [Fe/H] | 0.66[2] dex |
| Rotational velocity (v sin i) | 169±4[3] km/s |
| Age | 8[6] Myr |
| Other designations | |
| i Sco, 22 Sco, CD−24°12695, HD 148605, HIP 80815, HR 6141, SAO 184429[7] | |
| Database references | |
| SIMBAD | data |
22 Scorpii is a B-type main-sequence star with a stellar classification of B3 V.[4] It is ten million years old[10] and has a high rate of spin with a projected rotational velocity of 169 km/s.[3] The star has about 4.4 times the mass of the Sun and is radiating 601 times the Sun's luminosity from its photosphere at an effective temperature of 16,683 K.[3]