These are astrocytes. Neurons get all the attention when it comes to brain cells, but there are other types of cell in there as well. Astrocytes are star-shaped cells that have long been considered "helper" cells with no functional purpose, but recent research has questioned that idea.
For example, here is an article on a study showing that astrocytes play a key role in the brain's timekeeping mechanisms. When these cells are disrupted in a mouse, it throws its whole day off, altering the timing of daily routines. As the articles says, they're real clock stars. Groan.
Sleep is a rhythm that affects us all, and astrocytes play a role in our daily shut-eye. As we've discussed before, astrocytes play a role in the brain's daily housekeeping mechanisms, and when we don't get enough sleep, they may kick into overdrive and cause the brain to "eat itself." Eww.