The composition of this binary system causes the primarystar 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.
The galactic position and direction of Spica relative to Earth'sSun. Note that, at this
extreme scale, the two stars are effectively in the same place.
The view from a hypothetical planet in the Spica system. Each of the bluestars 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 a massivestar, intermediate on the scale between a subgiant and a true giant. It is more than ten times more massive than the Earth'sSun.
Spica lies at the heart of a binarystar, 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 brighteststar in the sky, after Antares in Scorpius.