When this is over, the cycle starts over; the original star dies and becomes a white dwarf. White Dwarf The core of a white dwarf star surrounds itself with layers of hydrogen, which still burn, continuing to fuse.
REM sleep is important because it is the restorative part of our sleep cycle. Typically, you begin the sleep cycle with a period of non-REM sleep followed by a very short period of REM sleep. The period of non-REM sleep is made up of stages 1 to 4. Each stage can last from 5 to 15 minutes.
The REM Sleep Stage. REM sleep is the second type of sleep, often kicking in only after a full cycle of NREM sleep. This is the stage where most dreaming occurs. REM is sometimes called paradoxical sleep because brain scans of people who are in REM show that their brains are very active, despite the fact theyâre fast asleep. However, while your brain is active, only your eyes can move. There are exceptions though.