Details Title: ASTRONOMY CHAPTER 12 Description: from book and outline paper Total Flash Cards: 30 Created: 04/01/2009 23:38:50		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Astronomy Flashcards
Cards in this set: Term What four laws determine the structure and evolution of a star? Definition 1. hydrostatic equilibrium 2. energy transport 3. conservation of mass 4. conservation of energy Term What is the maximum mass of a main sequence star? Definition 100 solar masses Term Where do stars of a very high mass loss mass? Definition in strong stellar winds Term What is the minimum mass of main sequence stars? Definition .08 Term Objects of mass less than .08 are called what? Definition brown dwarfs Term Why do stars have finite lifetime? Definition because they have a final supply of H Term Do massive stars have shorter or longer lifetime? Definition shorter Term What is the core filled with after Hydrogen is done burning? Definition helium Term what exists around the core? Definition a shell of burning hydrogen Term When the star expands to become a red giant, what happens to the surface? Definition it cools Term True or false: at some point the sun will expand past the earths surface Definition true Term What is the new state called with Hydrogen in the core stops burning and the matter enters this new state? Definition degenerate matter Term What happens in Triple Alpha Process? Definition helium is converted into carbon, oxygen and energy. (a core of C and O are formed) Term Stars more massive than _________ masses can fuse elements heavier than carbon and oxygen. Definition 8 solar masses Term Stars of mass less than 4 times the mass of the sun stop fusion at the formation of what? Definition Carbon oxygen core Term Stars of mass greater than 8 times the mass of the sun stop fusion at the formation of what? Definition Fe core Term Which stars never burn anything heavier than hydrogen? Definition red dwarfs Term What can be used as evidence of stellar evolution? why? Definition star clusters, because all the stars will have the same age Term More massive stars evolve more or less quickly than less massive stars? Definition more quickly Term If the stars are plotted on a H-R diagram, what stars would be missing? Definition the more massive stars Term What do mathematical stellar models show? Definition how rapidly a star uses its fuel in each layer Term What is the zero-age main sequence? Definition the line in the H-R diagram where contracting stars begin fusing hydrogen and reach stability Term What does the life expectancy of a main sequence star depend on? Definition its mass Term What does helium fusion produce? Definition carbon and oxygen Term What are the two types of star clusters? Definition 1. open clusters 2. globular clusters Term What is an open cluster? Definition contains 100 to 1000 stars and have open, transparent appearnce; young Term What are globular clusters? Definition 10^5 to 10^6 stars and are densely packed in a spherical shape; older Term What is the turn off point? Definition the location on the main sequence where the stars turn off to the right and become giants Term What is the difference between variable stars and intrinsic variable stars? Definition variable stars: change in brightness I.V.S: change in brightness because of internal processes Term What are two examples are proof that stars evolve? Definition the cepheid and RR Lyrae variable stars