Delta Scorpii

Basic parameters of the Delta Sco system

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The entire system

Brightness before 2000 at various wavelengths

Band U B V R I J H K L M
Wavelength (microns) 0.36 0.44 0.55 0.70 0.90 1.25 1.62 2.20 3.50 4.80
Magnitude 1.29 2.20 2.32 2.37 2.50 2.61 2.63 2.70 2.71 2.77

Distance: 123±15 pc (from HIPPARCOS parallax, 8.12±0.88 mas)

Interstellar extinction Av = 0.14 mag

Orbital elements

Parameter Value Reference
Period, P 10.806±0.003 years Aims, Tycner, & Zavala (2011)
Eccentricity, e 0.94±0.01 Miroshnichenko et al. (2001)
Periastron longitude –1°±5° Miroshnichenko et al. (2001)
Node line longitude 175° Miroshnichenko et al. (2001)
Inclination angle 38°±5° Miroshnichenko et al. (2001)
Periastron time 2000 2000 September 9±3 Miroshnichenko et al. (2001)
Periastron time 2011 2011 July 2±1 Aims, Tycner, & Zavala (2011)

Primary companion

Parameter Value Reference
Spectral type B0.3 IV  
Effective temperature, Teff 27500 K Grigsby et al. (1992)
Surface gravity, log g 4.0 Grigsby et al. (1992)
Luminosity, log L/Lsun 4.4±0.1 Miroshnichenko et al. (2001)
Radius, in Rsun 7.0 Miroshnichenko et al. (2001)
Projected rotational velocity, v * sin i 148±8 km/s Brown & Verschuuren (1997)

Secondary companion

Brightness ratio to the primary: 1.5-2.0 mag in the V-band

References:

Aims, Tycner, & Zavala 2011, In Proc. IAU Symp. 272 (in press)

Brown & Verschuuren 1997, A&A, 319, 811

Grigsby et al. 1992, ApJS, 78, 205

Hartkopf et al. 1996, AJ, 111, 370

Miroshnichenko et al. 2001, A&A, 377, 485


Last updated: 26-Jan-2011