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.
You need to sleep eight to 10 hours continuously to cycle through these stages three to four times. Every time you cycle the length of the REM sleep increases while the deep NREM decreases until you have a good 30 minutes in dream sleep without any deep sleep occurring, that is considered healthy sleep.