Beta Scorpii
Beta Scorpii (β Scorpii, abbreviated Beta Sco, β Sco) is a multiple star system in the southern zodiac constellation of Scorpius. It bore the traditional proper name of Acrab /ˈækræb/, though the International Astronomical Union now regards that name as applying only to the β Scorpii Aa component.
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Scorpius |
| HR 5984 | |
| Right ascension | 16h 05m 26.23198s |
| Declination | –19° 48′ 19.6300″ |
| Apparent magnitude (V) | 2.62 |
| HR 5985 | |
| Right ascension | 16h 05m 26.57128s |
| Declination | –19° 48′ 06.8556″ |
| Apparent magnitude (V) | 4.92 |
| Characteristics | |
| HR 5984 | |
| Spectral type | B1V (B0.5IV-V + B1.5V) |
| U−B color index | –0.08 |
| B−V color index | –0.08 |
| HR 5985 | |
| Spectral type | B2V |
| U−B color index | –0.70 |
| B−V color index | –0.02 |
| Astrometry | |
| HR 5984 | |
| Radial velocity (Rv) | –1.0 km/s |
| Proper motion (μ) | RA: –5.20 mas/yr Dec.: –24.04 mas/yr |
| Parallax (π) | 8.07 ± 0.78 mas |
| Distance | 400 ± 40 ly (120 ± 10 pc) |
| Absolute magnitude (MV) | –3.92 / –2.60 |
| HR 5985 | |
| Radial velocity (Rv) | –3.6 km/s |
| Proper motion (μ) | RA: –5.07 mas/yr Dec.: –25.87 mas/yr |
| Parallax (π) | 8.19 ± 1.17 mas |
| Distance | approx. 400 ly (approx. 120 pc) |
| Absolute magnitude (MV) | –1.83 (Ea: +0.24) |
| Details | |
| β Sco Aa | |
| Mass | 15.0 M☉ |
| Radius | 6.3 R☉ |
| Luminosity | 31,600 L☉ |
| Temperature | 28,000 K |
| β Sco Ab | |
| Mass | 10.4 M☉ |
| Radius | 4.0 R☉ |
| Luminosity | 7,900 L☉ |
| Temperature | 26,400 K |
| β Sco C | |
| Mass | 8.2 M☉ |
| Radius | 2.9 R☉ |
| Luminosity | 3,200 L☉ |
| Surface gravity (log g) | 3.8 cgs |
| Temperature | 24,000 K |
| Rotational velocity (v sin i) | 55 km/s |
| β Sco Ea | |
| Mass | 3.5 M☉ |
| Radius | 2.4 R☉ |
| Luminosity | 126 L☉ |
| Surface gravity (log g) | 4.2 cgs |
| Temperature | 13,000 K |
| Rotational velocity (v sin i) | 5 km/s |
| Age | 6.3 Myr |
| Other designations | |
| β1 Sco: BD–19 4307, HD 144217, HIP 78820, HR 5984 | |
| β2 Sco: BD–19 4308, HD 144218, HIP 78821, HR 5985 | |
| Database references | |
| SIMBAD | β Scorpii |
| β1 Scorpii | |
| β2 Scorpii | |
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.