Delta Scorpii
Basic parameters of the Delta Sco system
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