Spica


Spica (α Virginis) is the brightest star in the constellation Virgo. Spica is about 1000 light years (ly) away from the sun.

Spica is a spectroscopic double star (A/B) and an ellipsoid variable star. Spica A is a pulsating star of the Beta-Cephei type. The brightness of Spica varies between +0.92 mag and +0.98 mag with a period of 4.0142 days. This slight variation in brightness is hardly noticeable visually.

Both components of Spica belong to spectral type B (B1 to B4), with the brighter star near the end of its stable life as a main sequence star. The two stars are among the hottest and therefore most bluish of the bright stars in the night sky. Due to the high temperature, a large part of the light is emitted in the invisible ultraviolet range.

On the list of the brightest stars in the night sky, Spica is ranked 15th.

Spica
Constellation Virgo
Right ascension 13h 25m 11.6s
Declination −11° 09′ 40.8″
Apparent magnitude 0.97 mag
Distance (250 ± 10) ly
Bayer designation α Virginis
Bright Star Catalogue HR 5056
Hipparcos Catalogue HIP 65474
SAO Catalogue SAO 157923
Position of Spica (α Virginis) in the constellation Virgo. Chart: International Astronomical Union in collaboration with the magazine Sky & Telescope