The type of star cluster where stars are densely packed in a somewhat spherical pattern is called a globular cluster.

Here are some key characteristics of globular clusters:

* Densely packed stars: They contain hundreds of thousands to millions of stars, all tightly bound together by gravity.

* Spherical shape: They have a roughly spherical shape, though they can be slightly elongated.

* Old age: Globular clusters are generally very old, dating back to the early universe.

* Population II stars: They are predominantly made up of Population II stars, which are older, metal-poor stars.

* Located in halos: They are found in the halos of galaxies, orbiting the galactic center.

Let me know if you'd like more details on any of these aspects!