Magnitude! Copy the following words into your vocab section. Copy the following words into your vocab section. Apparent Magnitude: How bright a star appears to be from Earth (observer’s perspective). Apparent Magnitude: How bright a star appears to be from Earth (observer’s perspective). Absolute Magnitude: How much light the star actually gives off. Absolute Magnitude: How much light the star actually gives off.

Life Cycle of a Star Stars Evolve…

Temperatures of Stars: Blue: 35,000 C or 63,032 F Blue: 35,000 C or 63,032 F White: 10,000 C or 18,032 F White: 10,000 C or 18,032 F Yellow: 6,000 C or 10,832 F Yellow: 6,000 C or 10,832 F Red-Orange: 5,000 C or 9,032 F Red-Orange: 5,000 C or 9,032 F Red: 3,000 C or 5,432 F Red: 3,000 C or 5,432 F Bunsen Burner (blue): 1,400 C Candle: 760 C Bunsen Burner (blue): 1,400 C Candle: 760 C

1 st Stage of Life 1 st Stage of Life Ball of gas and dust that is pulled together by gravity Ball of gas and dust that is pulled together by gravity Nuclear fusion starts as gas cloud becomes denser and hotter Nuclear fusion starts as gas cloud becomes denser and hotter Nuclear Fusion  hydrogen atoms fuse into helium Nuclear Fusion  hydrogen atoms fuse into helium Creates the intense energy found in stars Creates the intense energy found in stars

Four types of stars make up the life of a star Four types of stars make up the life of a star Main Sequence Main Sequence Giants Giants Super Giants Super Giants White Dwarfs White Dwarfs

Main Sequence (the Sun) Main Sequence (the Sun) 2 nd stage 2 nd stage Longest stage Longest stage Hydrogen changes into helium which creates enormous amounts of energy Hydrogen changes into helium which creates enormous amounts of energy The size of the star does not change much The size of the star does not change much

Giants and Supergiants Giants and Supergiants 3 rd stage 3 rd stage Main Sequence star becomes a red giant Main Sequence star becomes a red giant Red giant  star that expands and cools once it loses all its hydrogen Red giant  star that expands and cools once it loses all its hydrogen Center shrinks and atmosphere grows large and cools Center shrinks and atmosphere grows large and cools

White Dwarf  small hot star that is the leftover center of an older star White Dwarf  small hot star that is the leftover center of an older star Final stage Final stage Can shine for billions of years before they extinguish Can shine for billions of years before they extinguish Observe life of a star (link) (link)

Hertzprung-Russell Diagram Hertzprung-Russell Diagram Shows the relationship between a star’s surface temperature and absolute magnitude Shows the relationship between a star’s surface temperature and absolute magnitude Used to study the lives of stars Used to study the lives of stars Most stars lie along the main sequence portion of the diagram Most stars lie along the main sequence portion of the diagram

Age of stars Age of stars Average stars become red giants then white dwarfs Average stars become red giants then white dwarfs More massive stars explode into a variety of objects More massive stars explode into a variety of objects

Supernova  gigantic explosion in which a massive star collapses Supernova  gigantic explosion in which a massive star collapses Occurs after a massive star uses up its fuel source Occurs after a massive star uses up its fuel source Neutron Star  a star that has collapsed to a point at which all particles are neutrons Neutron Star  a star that has collapsed to a point at which all particles are neutrons A neutron star that spins and sends out beams of radiation is called a pulsar A neutron star that spins and sends out beams of radiation is called a pulsar

Black Hole  an object that is so massive that light cannot escape its gravity Black Hole  an object that is so massive that light cannot escape its gravity Remnants of a supernova Remnants of a supernova Astronomers can detect black holes by using X-ray telescopes Astronomers can detect black holes by using X-ray telescopes

Question 1 What kind of a star is the sun? What kind of a star is the sun?

Answer Main Sequence Main Sequence

Question 2 What is the H-R diagram? What is the H-R diagram?

Answer A graph that shows the relationship between a star’s temperature and absolute magnitude A graph that shows the relationship between a star’s temperature and absolute magnitude

Question 3 What are the four main types of stars? What are the four main types of stars?

Answer Main-Sequence Main-Sequence Giants and Supergiants Giants and Supergiants White Dwarfs White Dwarfs