The type of star cluster where the stars are more densely packed and form a somewhat spherical pattern is called a globular cluster.

Here's why:

* Globular clusters are tightly bound groups of hundreds of thousands to millions of stars. They are older than open clusters and contain mostly older, redder stars. Their spherical shape comes from the gravitational pull of all the stars in the cluster.

* Open clusters, on the other hand, are more loosely bound and contain fewer stars, typically only a few hundred. They are younger and often have a more irregular shape.

Let me know if you have more questions about stars or star clusters!