Hubble Sees a Unique Cluster: One of the Hidden 15
Palomar 2 is part of a group of 15 globulars known as the Palomar clusters. These clusters, as the name suggests, were discovered in survey plates from the first Palomar Observatory Sky Survey in the 1950s, a project that involved some of the most well-known astronomers of the day, including Edwin Hubble. They were discovered quite late because they are so faint -- each is either extremely remote, very heavily hidden behind blankets of dust, or has a very small number of remaining stars. Read more