What is a major characteristic of globular clusters like M13?

Globular clusters, such as M13, are dense collections of stars that orbit the core of galaxies. A major characteristic of these clusters is their high concentration of stars within a relatively small volume. This density allows for a large number of stars to exist in a compact area, leading to the striking appearance of a bright, spherical cluster when observed through telescopes.

The stars in globular clusters are often older, typically older than the stars found in the surrounding galaxy, and they exhibit a more uniform distribution of stellar populations. This stark contrast with other stellar formations, such as open clusters, where stars are more loosely associated and tend to be younger and less densely packed, highlights the unique nature of globular clusters.

In contrast, the other options do not accurately describe the nature of globular clusters. They do not consist of loose associations of young stars, nor are they characterized by regions of intense gas and dust, as these elements are more often found in nebulae rather than globular clusters. Additionally, globular clusters are not remnants of supernova explosions; instead, they are ancient structures formed early in the history of the universe, containing stars that have survived billions of years.