Beta Scorpii
From Freepedia
| Observation data Epoch J2000.0 | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 05m 26.7s |
| Declination | -19° 48' 20" |
| Apparent magnitude (V) | β¹; 2.56 β²; 4.90 |
| Characteristics | |
| Spectral type | B0.5V+B2V |
| B-V color index | -0.08 |
| U-B color index | |
| Variable type | |
| Astrometry | |
| Radial velocity (Rv) | ? km/s |
| Proper motion (μ) | RA: -0.00675"/yr Dec.: -0.02489"/yr |
| Parallax (π) | 0.00615" ± 0.00115" |
| Distance | 530 ± 97 ly (163 ± 30 pc) |
| Absolute magnitude (MV) | β¹; -3.50 β²; -1.16 |
| Details | |
| Mass | ? M☉ |
| Radius | 19 R☉ |
| Luminosity | 3000 L☉ |
| Temperature | β¹; 27 000 K β²; 22 000 K |
| Metallicity | |
| Rotation period | |
| Age | ? years |
| Other designations | |
Beta Scorpii (β Sco / β Scorpii) is a star system in the constellation Scorpius. It also has the traditional names Acrab, Akrab or El Acrab, as well as Graffias, a name it shares with Xi Scorpii.
Observed through a small telescope, Beta Scorpii is found to be a binary star with a separation between the two components of 14 arcseconds, putting them at least 2200 Astronomical Units (AU) apart. They are both hot, B-class stars at least 10 times as massive as our own Sun, and will have a short lives. In fact, both are expected to end their stellar evolution in massive supernovae.
Beta-1 Scorpii, the brighter of the pair, has another companion 0.5 arcseconds, or about 80 AU, distant. Furthermore, both Beta-1 Scorpii and Beta-2 Scorpii, the two hot, B-class stars, are themselves thought to be spectroscopic binaries, brining the total number of stars in the system to five.
Because it is close to the ecliptic, Beta Scorpii can be occulted by the Moon and, very rarely, by planets. The last occultation by a planet took place on 13 May 1971, by Jupiter.
Categories: Star stubs | Bayer objects | Spectroscopic binaries | Multiple stars | Blue-white dwarfs | Scorpius constellation
