To study this globular cluster, located in the constellation Columba, astronomers measured the brightness and color of over 1,300 stars. In this way, they determined that the cluster is over 10 billion years oldΓÇömore than twice the age of our solar systemΓÇö and that it contains proportionally 20 times less iron than our Sun. Fourteen billion years ago, when NGC 1851 was formed, there were almost no heavier elements such as iron in the galaxy; these formed later, through nuclear fusion inside stars.
In the time since this globular cluster formed, there have been several generations of stars to generate heavy elements and release them into the galaxy. For
