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Alpha Virginis, 67 Virginis

Proper NameSpica
Bayer DesignationAlpha Virginis
Flamsteed Number67 Virginis
HR (BSC)5056
Right Ascension13h 25m 12s
Declination-11° 9' 41"
Distance250 light years
77 parsecs
MagnitudeApparent: +1.05
Absolute: -3.37
Spectral ClassB1IV blue subgiant (primary), B1V blue main sequence star (secondary)
Optimum VisibilityApril / May
NotesThe composition of this binary system causes the primary star to take on a somewhat ellipsoidal shape, in turn causing periodic changes in its brightness as the system rotates over a period of just over four days.
Location of Spica

The blue star Spica is Virgo's brightest by far, and one of the brightest stars in the entire sky. It lies near the Ecliptic in the southern regions of its home constellation.

Relative Galactic Position of Spica

The galactic position and direction of Spica relative to Earth's Sun. Note that, at this extreme scale, the two stars are effectively in the same place.

Spica and its companion

The view from a hypothetical planet in the Spica system. Each of the blue stars within the system expels particle winds, which clash to send powerful X-rays out into space. This radiation means that, even if the system contains any planets like that shown here, they are very unlikely to support any kind of life.

The name 'Spica' is Latin; it means 'Ear of Corn'. The star it refers to is a bright and hot blue star about 250 light years (about 80 parsecs) from the Earth.

Spica is a massive star, intermediate on the scale between a subgiant and a true giant. It is more than ten times more massive than the Earth's Sun.

Spica lies at the heart of a binary star, and is circled by a much fainter dwarf companion, causing its brightness to vary slightly every four days. Spica's magnitude is +0.9, making it the sixteenth brightest star in the sky, after Antares in Scorpius.

Imagery provided by Aladin sky atlas


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