Delta Scorpii
Delta Scorpii (Latinised from δ Scorpii, abbreviated Delta Sco, δ Sco) is a binary star (the presence of a third star in the system is being debated) in the constellation of Scorpius. The primary star is named Dschubba /ˈdʒʌbə/.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 00m 20.00528s |
| Declination | −22° 37′ 18.1431″ |
| Apparent magnitude (V) | 1.59 - 2.32 |
| Characteristics | |
| Spectral type | B0.3 IV + B1-3V |
| U−B color index | −0.920 |
| B−V color index | −0.124 |
| Variable type | γ Cas |
| Astrometry | |
| Radial velocity (Rv) | −7 km/s |
| Proper motion (μ) | RA: −10.21 mas/yr Dec.: −35.41 mas/yr |
| Parallax (π) | 6.64 ± 0.89 mas |
| Distance | 136.0 pc |
| Absolute magnitude (MV) | −3.8 |
| Orbit | |
| Period (P) | 10.8092±0.0005 yr |
| Semi-major axis (a) | 0.09874±0.00007" (13.5±0.1 AU) |
| Eccentricity (e) | 0.936±0.003 |
| Inclination (i) | 36±1° |
| Longitude of the node (Ω) | 174.0±2.5° |
| Periastron epoch (T) | 2011 July 3rd |
| Argument of periastron (ω) (secondary) | −2.3±3.8° |
| Semi-amplitude (K1) (primary) | 23.9±0.8 km/s |
| Details | |
| δ Sco A | |
| Mass | 13 M☉ |
| Radius | 6.7 R☉ |
| Luminosity | 38,000 L☉ |
| Surface gravity (log g) | 3.92 cgs |
| Temperature | 27,400 K |
| Rotational velocity (v sin i) | 180 km/s |
| δ Sco B | |
| Mass | 8.2 M☉ |
| Temperature | 20-24,000 K |
| Age | 9-10 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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