- Delta Scorpii
-
Dschubba, δ Sco 
Dschubba is δ star in one of the Scorpion's claws.Observation data
Epoch J2000 Equinox J2000Constellation Scorpius Right ascension 16h 00m 20.0s Declination -22° 37′ 18″ Apparent magnitude (V) 2.29 Characteristics Spectral type B0.2 IV U−B color index -0.909 B−V color index -0.124 Variable type γ Cas Astrometry Radial velocity (Rv) -7 km/s Proper motion (μ) RA: -8.67 mas/yr
Dec.: -36.9 mas/yrParallax (π) 8.12 mas Distance 401.67041871921 ly
(123.15270935961 pc)Details Mass 6.5[citation needed] M☉ Radius 5 R☉ Luminosity 14,000(bolometric) L☉ Temperature 28,000 K Metallicity ? Rotation 181 km/s. Age ? years Other designations Delta Scorpii (δ Sco, δ Scorpii) is a star in the constellation Scorpius. It has the traditional name Dschubba (or Dzuba, from Arabic jabhat, "forehead" (of the scorpion) or also Iclarcrau or Iclarkrav.
Because Delta Scorpii is near the ecliptic it is occasionally occulted by the Moon, or (extremely rarely) by planets.
Variability
In June 2000, Delta Scorpii was observed by Sebastian Otero to be 0.1 magnitudes brighter than normal. Its brightness has varied since then and has reached as high as magnitude 1.6 or 1.7, altering the familiar appearance of Scorpius. Spectra taken after the outburst began have shown that Delta Sco is throwing off luminous gases from its equatorial region. As of 2005 the flareup continues. Although the brightness varies, it remains well above its previous constant magnitude.
Companion stars
Dschubba is accompanied by a class B star that orbits the primary every 20 days at a distance comparable to the distance from the Sun to Mercury. Furthermore, there is a star that takes about 10 years to orbit Dschubba in a highly eccentric orbit that takes it close in to the primary once a decade. The last close encounter of these two stars happened in mid-2000 and it may have triggered the outburst of the primary star. A possible fourth companion star lies at about twice the distance again from the main star.
External links
- *Jim Kaler's Stars, University of Illinois: Dschubba
- Delta Scorpii brighter than ever (Sky and Telescope, February 4, 2002)
- Delta Scorpii still showing off (Sky and Telescope, June 25, 2003)
Bayer α (Antares) • β (Graffias) • δ (Dschubba) • ε • ζ¹ • ζ² • η • θ (Sargas) • ι¹ • ι² • κ (Girtab) • λ (Shaula) • μ¹ (Denebakrab) • μ² • ν (Jabbah) • ξ • ο • π • ρ • σ (Al Niyat) • τ (Alniyat) • υ (Lesath) • χ • ψ • ω¹ • ω² • b • c¹ • c² • d • i • k • A • G (γ Tel) • QFlamsteed 1 (b) • 2 (A) • 3 • 4 • 5 (ρ) • 6 (π) • 7 (δ, Dschubba) • 8 (β, Graffias) • 9 (ω¹) • 10 (ω²) • 11 • 12 (c¹) • 13 (c²) • 14 (ν, Jabbah) • 15 (ψ) • 16 • 17 (χ) • 18 • 19 (ο) • 20 (σ, Al Niyat) • 21 (α, Antares) • 22 (i) • 23 (τ, Alniyat) • 25 • 26 (ε) • 27 • 34 (υ, Lesath) • 35 (λ, Shaula) • 51 Lib (ξ) • 61 Nor • 62 Nor • 64 NorNearby Other List Categories:- Scorpius constellation
- Bayer objects
- B-type subgiants
- Stars with proper names
Wikimedia Foundation. 2010.