Exploring the Night Sky with Hubble’s Caldwell Catalog Posted on December 30, 2019 by Frank Cisco This loose collections of stars, known as an open star cluster, is image 100 of the Caldwell catalog. via NASA https://ift.tt/2tZEcx6 Share this: Click to share on X (Opens in new window) X Click to share on Facebook (Opens in new window) Facebook Like Loading... Related