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.
There are 4 stages to NREM sleep that need to occur before REM sleep begins. (The following stages are found in the Quick Series Guide to Healthy Sleep) STAGE 1: Light sleep, lasts about 10 minutes. During this time, you feel calm and experience sudden arm and leg movement. Your heart rate lowers and the eyes open without awareness. If you are awakened you feel in a state of âhalf-sleepâ. STAGE 2: Begins a sleep that lasts about 30 â 45 minutes. During this time there is lack of movement, you become oblivious to your surroundings. If you wake up during this time, you do not remember your dreams. STAGE 3: Brief time before Stage 4.