STAR NOTES A star is a sphere of hot gas that emits light and radiation We see different constellations throughout the year because different portions of the universe are visible to us during that time ( the Earth revolves around the sun) We use light years to determine the distance to stars Stars

All energy from stars comes from thermonuclear reactions (fusion) in the core Fusion is 2 small atomic nuclei joining to form one atom

Life of a star All stars are held together by gravity**

The Hertzsprung – Russell diagram Our sun is an average,yellow,main sequence star

All the energy the sun provides to the Earth was previously contained in the atoms of the sun. All stars radiate light, heat, and electromagnetic waves The brightness of a star is determined by the size, distance, and temperature

The electromagnetic spectrum contains all the transverse waves in order of their wavelength and frequency: Radio, infrared, visible, ultraviolet, x-rays, gamma rays