Unit 4 Introduction 1 How many powers of ten separate the approximate diameter of Earth North and Central America from the diameter of our Solar System the orbits of Neptune and Pluto 2 How many powers of ten separate the diameter of the Solar System and the diameter of the milky way galaxy a 6 a 8 3 How much bigger is the Earth than quarks sub atomic particles a 1023 times 4 What is the name of the nearest large spiral galazy to our own Milky Way in the Local Group a The Andromeda Galaxy Unit 4 Part 1 Galaxy Classification 1 Which Galaxy do you come from a The Milky Way 2 Why is our Galaxy called the Milky Way a The term Milky Way Galaxy is derived from the Greek word for milk and there appeared to be a stream of milk running across the sky 3 What kind of Galaxy is the Milky Way 4 What color of stars are found in the young star clusters in the disk of the Whirlpool galaxy a Spiral a Blue 5 Why do hydrogen gas clouds glow red a Electromagnetic radiation from nearby stars heats the clouds until they glow red 6 Why are there dark lines in the spiral arms of the Whirlpool Galaxy a They are regions of dust that block the light of the stars 7 In what part of spiral galaxies do new stars form behind them a In the Spiral Arms 8 Why can t Thomasin find any constellations she recognizes a From any position far outside the Solar System the stars are seen at different angles and fall out of the constellations traditional shapes 9 What causes the long tail to protrude from this galaxy a Tidal forces caused by interaction with another galaxy are drawing the material off 10 Why are the star clusters in the tidal tail blue a Blue stars in these newly active star forming regions far outshine the less massive red stars 11 Compared to spiral galaxies elliptical galaxies have a les gas less dust and less new star formation 12 Among Spiral galaxies an SBa has a A bar tight smooth spiral arms and a large bulge 13 What is the difference between an E0 and an E7 galaxy a The E7 has an oval shape and the E0 is circular 14 What category do astronomers use if a galaxy does not fit into the spiral or elliptical category a Irregular 15 What happens to the planets in a galaxy when that galaxy collides with another galaxy a Nothing because the spaces between stellar systems in a galaxy is much larger than their size 16 What kind of galaxy will be the final result from the collision of the Milky Way and Andromeda galaxies a A large elliptical 17 What is the result when gas clouds from both of the colliding galaxies meet a The clouds crushing down on each other starts a burst of new star formation a telescope 18 What are the 3 parts of the spiral galaxy and which 2 might you see through a Disk bulge and halo would see bulge and disk and wouldn t see halo 19 What are the friends other types of galaxies close to ours a Nearby dwarf galaxies clustered around the spiral galaxy 20 How might a nearby neighbor change the shape of this galaxy a The merger of two spiral galaxies may give rise to an elliptical galaxy 21 What is this galaxy doing that keeps it from being idle a Stars are forming in the spiral arms and the disk is rotating Unit 4 Part 2 Distant Universe Distant Past 1 How far does light travel in 100 years a 100 lightyears 2 How many galaxies are needed to get a fair sample to determine what 3 About what percentage of Hubble Deep Field HDF galaxies do astronomers 4 Does the universe look the same in the directions of HDFN and HDFS fractions of galaxy types statistically similar 5 How old was the universe when light from the most distant galaxies in the Hubble Ultra Deep Field was emitted a 800 million years 6 What would describe the earliest galaxies fraction are elliptical a 35 45 find are irregular a 70 a Yes a They were undergoing rapid changes 7 How do tadpole galaxies get their shape a They represent merging galaxies 8 Why didn t they see flickering brightness that would show black holes were a There s a delay between the merger and time gas and stars flow into eating gas from mergers the black hole 9 How might light be captured a Hubble Space Telescope instantly 11 What is nature s speed limit a The Speed of Light 10 Why won t an object be seen as it is today if you could go to its location a Light has been traveling a large distance through space since it left the object we see the object as it was in the past 12 If the objects seen in the past are galaxies how might they have changed a The galaxies were more irregular and patchy in the past than they are at present Field Unit 4 Part 3 Implications of the Hubble Deep Field 1 Why was it important to have a boring patch of sky for the Hubble Deep a To minimize the number of objects in the view that were local to our own galaxy 2 How many stars are in each galaxy in the Hubble Deep Field a From one billion 109 to a hundred billion 1011 3 Why did these astronomers take so many different pictures of the same patch of sky a To average over many images and keep only the consistent object details filtering out random single exposure events like charged particles from the solar wind 4 How far away is most distant galaxy seen in the Hubble Deep Field a A About twelve billion 1 2x1010 light years 5 How many galaxies are there in the observable universe a Fifty to a hundred billion 5x1010 1011 6 How many stars are there in the observable universe a 100 billion x 10 billion 1022 7 How tiny a spot is the Hubble Deep Field a The size of President Roosevelt s eye on a dime held at arm s length 8 Why does the image show very few stars a It was chosen so that bright stars in the Milky Way Galaxy do not interfere with our picture of the distant universe 9 About how many dots are seen in the Hubble Deep Field image just within that image What are the dots seen in the Hubble Deep Field 10 How many galaxies are there in the part of the universe we can a 3000 galaxies observe a 50 100 billion Unit 4 Part 4 Quasars and gamma ray bursts 1 Where do we observe black holes a In orbit around stars in binary systems in the center of the Milky Way Galaxy In the centers of elliptical galaxies and in quasars 2 Which are more massive the black holes in x ray binaries or those …