From the November 2009 issue

How do globular clusters form? Can such massive concentrations of stars arise from gas clouds alone, or is a central black hole required?

Derek Leaist, Cloverville, Nova Scotia
By | Published: November 23, 2009 | Last updated on May 18, 2023
January 2010 globular cluster M80
Globular cluster M80, like other globulars, likely formed from condensing clouds of interstellar material.
The Hubble Heritage Team (AURA/STScI/NASA)

For such a cluster to form, huge amounts of interstellar material must compress into a tiny volume very quickly.

Old globular clusters, such as those living in the halo of the Milky Way, certainly host stellar-mass black holes. However, such black holes are the products of stellar evolution within their clusters and do not influence their clusters’ formation.