Rho Scorpii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 15h 56m 53.07624s |
| Declination | −29° 12′ 50.6612″ |
| Apparent magnitude (V) | 3.86 |
| Characteristics | |
| Spectral type | B2 IV |
| U−B color index | -0.82 |
| B−V color index | -0.20 |
| Astrometry | |
| Radial velocity (Rv) | −0.40 km/s |
| Proper motion (μ) | RA: −15.68 mas/yr Dec.: −24.88 mas/yr |
| Parallax (π) | 6.91±0.19 mas |
| Distance | 470 ± 10 ly (145 ± 4 pc) |
| Absolute magnitude (MV) | −1.93 |
| Orbit | |
| Period (P) | 4.0033 d |
| Eccentricity (e) | 0.27 |
| Periastron epoch (T) | 2442178.6060 JD |
| Argument of periastron (ω) (secondary) | 231° |
| Semi-amplitude (K1) (primary) | 16.40 km/s |
| Details | |
| Mass | 7.94±0.55 M☉ |
| Radius | 4.36 R☉ |
| Luminosity (bolometric) | 3,432 L☉ |
| Temperature | 21,150 K |
| Rotational velocity (v sin i) | 113 km/s |
| Age | 13.7 Myr |
| Other designations | |
| Iklil, 5 Scorpii, ADS 9846, CCDM J15569-2913A, FK5 3258, GC 21398, HD 142669, HIP 78104, HR 5928, SAO 183957, CD−28°11714 | |
| Database references | |
| SIMBAD | data |
Rho Scorpii (ρ Scorpii, abbreviated Rho Sco, ρ Sco) is a double star in the constellation of Scorpius. It has an apparent visual magnitude of +3.87, which is bright enough to be seen with the naked eye. Based upon parallax measurements, it is located approximately 472 light years from the Sun. At that distance, the visual magnitude of the system is reduced by 0.07 due to extinction from interstellar dust. It is a member of the Upper Scorpius OB association.
It has two components, designated Rho Scorpii A and B. Rho Scorpii A is itself a single-lined spectroscopic binary whose components are designated Rho Scorpii Aa (formally named Iklil /ˈɪklɪl/, traditionally the name for several neighboring stars) and Ab.