White Dwarfs in Globular Cluster M4
![](https://cdn.sci.esa.int/documents/34247/35306/1567220808465-i_screenimage_29970.jpg)
Depicts: M4, NGC 6121
Copyright: NASA and A. Feild
The white dwarfs are not part of the main-sequence stars because they have used up their hydrogen fuel. These dying stars are fainter and yet hotter than their main-sequence relatives. NASA's Hubble Space Telescope hunted for the faintest and coolest of the white dwarfs [bottom of white dwarf population.]
Last Update: 1 September 2019