Hercules cluster definition of Hercules cluster in the Free Online Encyclopedia.

Hercules cluster, giant globular star cluster star cluster, a group of stars near each other in space and resembling each other in certain characteristics that suggest a common origin for the group. Stars in the same cluster move at the same rate and in the same direction.
..... Click the link for more information. in the northern constellation Hercules Hercules (hûr`kyəlēz'), in astronomy, northern constellation located between Lyra and Corona Borealis.
..... Click the link for more information. ; cataloged as M13 or NGC 6205. The cluster is just visible to the naked eye and is the best example of a globular cluster visible in the Northern Hemisphere. Its angular diameter is about 2-3 that of the full moon, and its linear diameter is 100 light-years light-year, in astronomy, unit of length equal to the distance light travels in one sidereal year . It is 9.461 × 10¹² km (about 6 million million mi). Alpha Centauri and Proxima Centauri, the stars nearest our solar system, are about 4.
..... Click the link for more information. . The entire cluster contains perhaps 100,000 or more stars. In its central portion, the stars are so close together that they cannot be resolved, despite the cluster's relatively near distance of 35,000 light-years; the separation between stars is estimated to be only a few astronomical units astronomical unit (AU), mean distance between the earth and sun; one AU is c.92,960,000 mi (149,604,970 km). The astronomical unit is the principal unit of measurement within the solar system, e.g., Mercury is just over 1-3 AU and Pluto is about 39 AU from the sun.
..... Click the link for more information. as compared to the normal interstellar separation of a few light-years.

Hercules cluster [′hər·kyə‚lēz ‚kləs·tər]

(astronomy)

A cluster of about 75 bright galaxies with a recession velocity of 6200 miles (10,000 kilometers) per second.