| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 17h50m 11.11291s[1] |
| Declination | −40° 05′ 25.5629″[1] |
| Apparent magnitude (V) | +4.82[2] |
| Characteristics | |
| Spectral type | A2 Ib[3] or A6 Ib[4] |
| U−B color index | +0.19[2] |
| B−V color index | +0.25[2] |
| Astrometry | |
| Radial velocity (Rv) | −10.2[5] km/s |
| Proper motion (μ) | RA: +3.90[1] mas/yr Dec.: −2.42[1] mas/yr |
| Parallax (π) | 1.28 ± 0.24 mas[1] |
| Distance | approx. 2,500 ly (approx. 800 pc) |
| Absolute magnitude (MV) | −4.59[6] |
| Details | |
| Mass | 8.8±0.2[4] M☉ |
| Luminosity | 5,798[7] L☉ |
| Temperature | 6,372[7] K |
| Age | 29.8±4.3[4] Myr |
| Other designations | |
ι2 Sco, CD−40° 11886, HD 161912, HIP 87294, HR 6631, SAO 228466 .[8] | |
| Database references | |
| SIMBAD | data |
ι2 Scorpii, Latinised as Iota2 Scorpii, is a single[9] star in tail of the zodiac constellationofScorpius. It has an apparent visual magnitude of +4.82,[2] and is visible to the naked eye. Because of parallax measurement errors, the distance to this star is only approximately known: it lies around 2,500 light years away from the Sun. It has a visual companion, a magnitude 11.0 star at an angular separation of 31.60 arcseconds along a position angle of 36°, as of 2000.[10]
In the literature, there are two different stellar classifications for this star: A2 Ib[3] and A6 Ib.[4] In either case it is an A-type supergiant star with an estimated age of 30[4] million years and a mass 8.8 times that of the Sun.[4] It shines with a luminosity 5,798 times the Sun's from an outer atmosphere that has an effective temperature of 6,372 K.[7] As with other stars of its type, ι2 Scorpii varies slightly in brightness, showing an amplitude of 0.05 in magnitude.[11]
