Radio image showing the size of red supergiantBetelgeuse's photosphere (circle) and the effect of convective forces on the star's asymmetric atmosphere as it expands beyond the orbit of Saturn.
Comparison between the red supergiantAntares (NN solar masses) and the Sun, shown as the tiny dot toward the upper right. The black circle is the size of the orbit of Mars. Orange giantArcturus (NN solar masses) is also included in the picture for size comparison.Size comparison between the Sun and VY Canis Majoris, an unstable hypergiant star of around NN solar masses
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Right to left: VY Canis Majoris compared to Betelgeuse, Rho Cassiopeiae, the Pistol Star and the Sun (not visible in this thumbnail). The orbits of Jupiter and Neptune are also shown.
R136a1, the most massive star known, is a blue hypergiantWolf-Rayet star of around 265 solar masses. Left to right size comparison: a red dwarf, the Sun, a blue dwarf, and R136a1. R136a1 is not the largest known star in terms of volume; this distinction belongs to VY Canis Majoris.
