Illustration comparing the sizes of several very large stars. The small blue star at the bottom is Rigel, in Orion. It looks puny in this image, but this is actually a blue supergiant, fully 85 000 times more luminous and 78 times the diameter of our Sun. On the scale of this diagram the Sun is, in fact, practically invisible. The three larger stars, all red supergiants, are, from smallest to largest, Antares, Betelgeuse and VY Canis Majoris (VY CMa). VY CMa is in fact the largest currently known star. Its diameter has been estimated to be between 1800 and 2100 times that of the Sun's. If placed at the centre of the Solar System VY CMa would reach almost to the orbit of Saturn.