Yesterday we showed you a video showing the globular cluster Omega Centauri, and answering the question as to whether or not a black hole was at its center. Today we look at what happens if you took that same data, and plotted it as a scatter graph of stars. On the X-axis of the scatter graph we have a stars temperature . On the Y-axis of the scatter graph we have a stars intrinsic brightness. This is called a Hertzsprung-Russell diagram. When applied to the globular cluster Omega Centauri, you can see some interesting things.
In this video, the stars in globular cluster Omega Centauri are rearranged according to their intrinsic brightness (vertical axis) and their temperature (horizontal axis). The temperature of a star dictates its apparent colour, with cooler stars being red and hotter ones being blue. The majority of stars at any given time fall into a wide band known as the main sequence, which passes from the top left (hot, bright stars) to the bottom right (cool, dim stars). However this is just a snapshot in time — as stars evolve they do not stay fixed to one point on the diagram for the whole of their lives.
Credit:
NASA, ESA, J. Anderson and R. van der Marel (STScI)
