Among the following, which star is a prominent feature in the constellation Hercules?

M13, also known as the Great Hercules Cluster, is indeed a prominent feature in the constellation Hercules. It is a globular cluster located approximately 25,000 light-years away from Earth and is one of the brightest globular clusters visible from the northern hemisphere. M13 is particularly well-known among amateur astronomers for its visibility even through small telescopes and binoculars, showcasing a dense concentration of stars. This makes it a popular target for observation during the summer months when Hercules is high in the sky.

While the other options represent well-known stars in the night sky, M13 is specifically tied to the constellation Hercules. Vega is part of the Lyra constellation, Antares belongs to Scorpius, and Polaris is situated in Ursa Minor. Each of these has its significance and brightness but does not hold the same recognition within the context of Hercules as M13 does.