WNHS Physical Science
Name:______Date:______Period:____
Notes #3: Life Cycle of a Star
WHAT ARE STARS?
= a huge sphere of very hot ______, that emits ______and other ______(______, ______, etc…)
●We use ______to describe a star’s distance from Earth.
○1 ly = 9.5 x 1015 meters
■= ______meters
HOW DO STARS BURN?
●A star is made up of ______and ______gases.
○At the core, ______takes place.
■H atoms ______(fuse) to form He, producing large amounts of ______and ______.
LUMINOSITY
= ______.
●Depends on a star’s ______, ______, and ______away.
○The brightest star (to Earth) is ______.
COLOR & TEMPERATRE
●Scientists use a star’s ______to determine its ______.
○Hot stars = ______energy = ______wavelength = ______!
○Cool stars = ______energy = ______wavelength = ______!
○Our sun appears ______because it gives off light most intensely at that ______.
LIFE CYCLE OF A STAR
1.______: Stars form from a cloud of ______& ______.
- NOTE: A Nebula is NOT considered a stage of star.
2.______: The dust and gas is pulled inward by ______and begins to ______and increase in ______.
3.______: ______begins to take place, releasing large amounts of ______.
- This is the ______of the star’s life.
- Our ______is in the main sequence.
4.______or ______: After billions of years, the star runs out of ______, and fusion ______.
- The layers will ______to form a red giant or red supergiant.
- The star appears red because it is ______.
LOW/MEDIUM MASS STARS
- ______:The outer layers continue expanding and begin ______the star.
- ______: A ______, ______star, the size of Earth, left once the outer layers leave.
- ______: A ______white dwarf.
5.______: The star ______once fusion completely stops.
- ______form from supernovas.
- ______, high-mass stars.
- ______, high-mass stars.
HR-DIAGRAMS
= a map of the different ______of stars
●Based on ______and ______
○Luminosity depends on ______, ______& ______.
○Temperature is directly related to ______.