15) astronomers discover a new astro in the pisces constellation 48 times as massive as planet jupiter. the spectrum of this object shows that it's not a nebula (not a diffuse cloud of gas). what might it be? a) an asteroid b) a brown dwarf c) anew star d) a planet e) a galaxy 16) two main sequence stars (04 and g3 spectral types) eclipse each other in a binary system. explain the two different dips observed in the light curve of the system resulting from the two stars passing in front of one another. 17) how could you determine the distance to a) a nearby star? c) a galaxy using cepheids? b) any star in our galaxy? 18) according to chandrasekhar's limit, the final fate of a star with a mass of 1.3 solar masses will be a: a) white dwarf b) neutron star c) black hole d) ms star e) nova 19) describe the steady state model of the universe. 20) what are the three observational proofs in support of the big bang theory discussed in class? 21) all stars visible from earth to the naked eye belong to a)galactic center b) solar system c) milky way d) andromeda galaxy e) none of the above 22) the absolute magnitudes of three main sequence stars are m 3, m-0 and m-5. which star is the reddest? a) star with m-0 b) star with m-3 c) star with m-5 d) it depends on the star's shape e) none of the above

Study guide for unit 2 ~ lesson 3 ,4, & 5 test, thursday, january 24th lesson 3 vocabulary erosion - deposition - landform- weathering- short answers 1. how do volcanic islands form? 2.why is deposition likely to occur outside a river bend? 3. in what conditions does soil form fastest? 4. which 2 earth’s systems interact to form a coral island? 5. a beach growing in size is most likely the result of 6. which type of islands are formed when a chunk of land breaks off from a larger landmass? long answers explain how plants can grow in small cracks of rock that do not appear to contain soil. lesson 4 vocabulary pollution - toxic - short answers 1. most farmers pollute soil by purposefully adding 2. what is the benefit of contour plowing? . 3. using nuclear power to produce electricity can cause water pollution by 4. why do scientists predict humans will run out of fossil fuels someday? 5.farmer spray crops with fertilizer and weed killer to the crops grow. how might this affect the hydrosphere? list two different ways you use fossil fuels. 1- 2- what are two other energy sources scientists and engineers are researching? 1- 2- lesson 5 vocabulary decompose- recycling - short answers 1. which of earth’s systems do you interact with when you wash your hands? 2. which of earth’s systems is polluted by exhaust gases from buses pollute? 3. why is it important to dispose of electronic devices properly? 4. where do people interact with all four of earth’s systems?