Details Title: ASTRONOMY CHAPTER 11 Description: from book and outline paper Total Flash Cards: 30 Created: 04/01/2009 21:33:36		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 does star formation generally occur from? Definition the cores of giant molecular clouds Term What two things do clouds need to do to form stars? Definition contract and heat up Term What are the four factors that resist the collapse of a cloud? Definition 1. thermal energy (pressure) 2. magnetic fields 3. rotation 4. turbulance Term What is another word for rotation? Definition angular momentum Term Previous star formation can trigger new star formation through what four things? Definition 1. shocks from supernovae 2. ionization fronts of hot massive O or B stars 3. collisions of giant molecular clouds 4. spiral arms in galaxies Term What is the pre-birth state of a star known as? Definition protostars Term What is the state of a protostar? Definition hydrogen to helium fusion not yet initiated Term Do higher mass stars evolve more or less rapidly? Definition more rapidly Term What does conservation of angular momentum lead to the formation of? Definition protostellar disks Term what are protostellar disks? Definition the birthplace of planets and moons Term What are disk of matter falling onto a protostar known as? Definition accretion disks Term What are Herbig-Haro objects? Definition Bipolar outflows die to accreted matter Term What is the Birth Line? Definition the line on the H-R diagram where a star emerges from the enshrouding dust cocoon Term What does the cone nebula give us strong evidence for? Definition star formation Term What are newly forming stars exposed by the ionizing radiation from nearby massive stars called? Definition evaporating gaseous globules (EGGs) Term What are large groups of stars that are formed from large masses of giant molecular clouds? Definition open clusters of stars Term What cycle do stars about the mass of the sun produce less energy? Definition PP Cycle Term Through was cycle where stars slightly more massive than the Sun produce energy? Definition CNO Cycle Term The two methods of energy transport in the sun include: Definition 1. radiative energy transport 2. convection Term How is energy generated in the sun? Definition nuclear fusion Term The structure of the sun is the basically the same for the stars of what mass? Definition approx. 1 solar mass Term Stars more massive than the sun have what kind of core and envelope? Definition convective core, radiative envelope Term What is hydrostatic equilibrium? Definition the state of a star by which the inward gravity is matched by outward pressure Term What does hydrostatic equilibrium determine? Definition interior structure of star Term What triggers star formation? Definition shock wave Term What are bok globules? Definition small, dark nebulae which contract to form stars Term How do stars make their energy? Definition same way as sun, proton-proton chain Term the CNO cycle is temperature sensitive. What is the minimum solar mass in which the CNO cycle will succeed? Definition 1.1 solar mass Term What is opacity? Definition the resistance in a gas to the flow of radiation Term What is the law of hydrostatic equilibrium? Definition the weight pressing on a layer of gas in a star must be balanced by the pressure in the gas