Death of sun-like Massive star death Elemental my dear Watson Novas Neutron Stars Black holes $200 $200 $200 $200 $200 $200 $400 $400 $400 $400 $400 $400 $600 $600 $600 $600 $600 $600 $800 $800 $800 800 $800 $800 $1000 $1000 $1000 $1000 $1000 $1000 $200 Black dwarfs What are cooled off white dwarfs? $400 Planetary nebula What is the ejected envelope, often bipolar, of a red giant surrounding a white dwarf $600 Red giant The "helium flash" occurs at what stage in stellar evolution? $800 100 million degrees Kelvin The temperature need to fuse helium into carbon is $1000 Helium build up in the core (less hydrogen in the core) and hydrogen burning shell expands What forces the evolution of a star off the main sequence? $200 once How many times can a star be a supernova? $400 A day A 20 solar mass star will stay on the main sequence for 10 million years, yet its iron core can exist for only a $600 It generates more heat and eventually collapses on itself A high-mass star dies more violently because? $800 It is the temperature needed to fuse elements higher than carbon. 600 million degrees Kelvin is important because $1000 At 8 solar masses a star will go through a violent ending, forming a Type II supernova and ending in a nuetron star or balck hole Why is the 8 solar masses significant in stellar evolution? $200 Hydrogen What is the element first fused to form stars? $400 Hydrogen and helium Nearly all the elements found in nature were formed inside stars, except for $600 nucleosynthesis The formation of heavier elements inside stars is called $800 neutron capture during a type II supernova explosion. The heaviest nuclei of all are formed by $1000 Fission of heavier elements into lighter Beyond the formation of iron, nuclear energy can be produced only by $200 Novas A surface explosion on a white dwarf, caused by falling matter from the atmosphere of its binary companion, creates what kind of object? $400 Neutrinos Most of the energy of the supernova is carried outward via a flood of $600 Type I supernova If a white dwarf gains enough mass it can become a $800 Type II Supernova The making of abundant iron niclei is typical of $1000 The sun is neither a binary star nor is it large enough to cause a supernova Most of the energy of the supernova is carried outward via a flood of $200 made of compressed neutrons in contact with each other. n a neutron star, the core is $400 Neutron star An object more massive than the sun but no larger than a city is a $600 Pulsars These objects spin very rapidly when they are young $800 The Lighthouse model The name of the model where we see a beam sweep across us in a pulsar is called $1000 X-ray bursters They are neutron stars on which accreted matter builds up, then explodes in a violent nuclear explosion. $200 Black hole A “failed” supernova undergoes core collapse but instead of forming a neutron star like a Type II supernova it forms a black hole. A hypernova ends up as a $400 Theory of Relativity Gravity is the result of curved space is an explanation of what theory? $600 In the middle of galaxies The largest supermassive black holes are found________________. $800 Neither matter or energy can escape because escape velocity would be more than the speed of light How does escape velocity relate to black holes $1000 2.8 km Event Horizon Math problem: Calculate the Scharzchild radius for the sun using the following: R=2GM/c2 M=1.9x1030 kg G=6.67x10-11 Nm2/kg2 C=3x108 m/sec $200 Shock waves from supernovae Star formation may be triggered by __________ which help gravity through compression of interstellar clouds to greater densities. $400 T Tauri Strong winds develop during which phase of a protostar? $600 When a protostar in about to become a main sequence star When does the T Tauri star occur? $800 They are young enough to not have most of their hydrogen not fused into helium. They do not evolve off until helium is built up. Most of stars life time is spent as a main sequence star. Why is the largest group of stars the main sequence stars? $1000 If <1.4 Solar masses will become a white dwarf (Red Giant throws off a planetary nebula) 1.4 to 3 solar masses becomes a neutron star from a Type II supernova explosion. Above 3 solar masses becomes a black hole What are three possible outcomes of stellar evolution? Which sized stars (in solar masses) on the Main Sequence are thought to become each of these?