In fact, Spica is a binary star, and is circled by an invisible 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.

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.

Spica is of the type classified as a 'dwarf', but this does not mean that it is a small star - it is more than ten times more massive than the Earth's Sun.

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.

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.