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