STARS Position of the Stars Stars during the night Distance Brightness Composition (what they are made of) Stars during the season Movement of the Stars
STARS Our solar system and stars belong to the milky Way galaxy Planets, moons, asteroids & other satellites do not “twinkle” as they reflect light Stars twinkle because they are so far away their light is a mere pinpoint by the time it reaches us and our atmosphere refracts it Our solar system and stars belong to the milky Way galaxy There are 5000-6000 stars visible to the naked eye in the northern hemisphere
Composition of Stars STARS (what they are made of) Hot Gases Hydrogen turns into helium in a nuclear reaction Nuclear reaction produces enormous amount of heat and light
Distance STARS Stars are light years away A light year is a measure of distance (how far light travels in a year – about 10 trillion km) The sun is our closest star - it takes 8 min for the sun’s light to travel to earth. Next closest star (Proxima Centauri) is 4 light years away and other stars are hundreds of light years away
STARS Brightness Measurement of a star’s brightness is referred to as “magnitude” The lower the magnitude measure (number) the brighter the star appears
Position of Stars STARS The earth’s axis points north toward Polaris, the North Star Nearing the horizon is located a belt of twelve constellations of the zodiac
Movement of the Stars STARS Movement of Movement of Stars during The seasons Movement of Star during The night
Movement of Stars during the night Polaris hardly moves at all because its location (aligned with earth’s axis) Circumpolar constellations move counter clockwise around the North Star (Big Dipper, Little Dipper & Cassiopeia) Other constellations rise in the East and set in the West Happens because the Earth rotates on its axis
Movement of Stars during the Seasons We see different constellations during different seasons (depending on the time of year) This is because Earth is orbiting around the sun The sun blocks the stars behind it from our view