light energy
... match with the known spectra of Hydrogen but not with Mercury – so the Sun contains Hydrogen! ...
... match with the known spectra of Hydrogen but not with Mercury – so the Sun contains Hydrogen! ...
GeoDome Notes
... The red star is a cool supergiant star. Its surface temperature is about 3400 degrees Kelvin, making it much cooler than our Sun (~6000 degrees Kelvin). It is a dying star having used up most of its fuel. It expands and contracts which changes its magnitude (measure of brightness) over a 6 year peri ...
... The red star is a cool supergiant star. Its surface temperature is about 3400 degrees Kelvin, making it much cooler than our Sun (~6000 degrees Kelvin). It is a dying star having used up most of its fuel. It expands and contracts which changes its magnitude (measure of brightness) over a 6 year peri ...
Homologous Expansion and Contraction Many problems in stellar
... while a positive value denotes a thermal runaway. As demonstrated above, if the gas conditions are degenerate, δ = 0, and again we have a runaway. However, suppose we are dealing with an ideal gas (which is the relevant condition, since the gas in the shell is outside the core). For core burning st ...
... while a positive value denotes a thermal runaway. As demonstrated above, if the gas conditions are degenerate, δ = 0, and again we have a runaway. However, suppose we are dealing with an ideal gas (which is the relevant condition, since the gas in the shell is outside the core). For core burning st ...
A time travel of 14 billion years
... Hubble was able to measure the distances to only a handful of other galaxies, but he realised that as a rough guide he could take their apparent brightness as an indication of their distance. The speed with which a galaxy was moving toward or away from us was relatively easy to measure due to the Do ...
... Hubble was able to measure the distances to only a handful of other galaxies, but he realised that as a rough guide he could take their apparent brightness as an indication of their distance. The speed with which a galaxy was moving toward or away from us was relatively easy to measure due to the Do ...
The Later Evolution of Low Mass Stars (< 8 solar masses)
... http://en.wikipedia.org/wiki/Ring_Nebula AGB stars are known to lose mass at a prodigious rate during their final stages, around 10-5 - 10-4 solar masses per year. This obviously cannot persist for much over 100,000 years. The mass loss is driven in part by the pulsational instability of the thin he ...
... http://en.wikipedia.org/wiki/Ring_Nebula AGB stars are known to lose mass at a prodigious rate during their final stages, around 10-5 - 10-4 solar masses per year. This obviously cannot persist for much over 100,000 years. The mass loss is driven in part by the pulsational instability of the thin he ...
Document
... to be sure, but also nitrogen from CNO processing and C and O from helium burning. It is thought that stars in this mass range are responsible for producing most of the nitrogen and maybe 60 – 80% of the carbon in the universe. The rest of carbon and most other elements comes from massive stars. ...
... to be sure, but also nitrogen from CNO processing and C and O from helium burning. It is thought that stars in this mass range are responsible for producing most of the nitrogen and maybe 60 – 80% of the carbon in the universe. The rest of carbon and most other elements comes from massive stars. ...
Star Formation
... gas is blown away, but its thermal energy comes from gravitational contraction, not fusion 4) The collapsing gas becomes a young stellar object with an accretion disk and jets 4) When the young stellar object begins fusing hydrogen into helium it becomes a true star ...
... gas is blown away, but its thermal energy comes from gravitational contraction, not fusion 4) The collapsing gas becomes a young stellar object with an accretion disk and jets 4) When the young stellar object begins fusing hydrogen into helium it becomes a true star ...
Old Final
... There are 10 T/F questions each worth 2 pts., 40 multiple choice questions each worth 5 pts. and your choice of 5 (out of 8 ) long answer questions worth 16 pts. each. True/False ( True = A, False = B , worth 2 pts each) 1. Increasing the density of a cloud makes it easier to form stars there ...
... There are 10 T/F questions each worth 2 pts., 40 multiple choice questions each worth 5 pts. and your choice of 5 (out of 8 ) long answer questions worth 16 pts. each. True/False ( True = A, False = B , worth 2 pts each) 1. Increasing the density of a cloud makes it easier to form stars there ...
8.2 Solar Nebula Theory and the Sun
... How the Solar System Formed • Tiny grains or small lumps collect in nebula – Attract others and build up to bigger, ...
... How the Solar System Formed • Tiny grains or small lumps collect in nebula – Attract others and build up to bigger, ...
Star Classification - University of Louisville
... surface temperatures are much higher, and shine white instead of red. When the Sun comes to the end of its life, it will become a White Dwarf. It will be much smaller than it is now, not quite as bright but twice as hot. Its matter (particles) will be more densely-packed together. ...
... surface temperatures are much higher, and shine white instead of red. When the Sun comes to the end of its life, it will become a White Dwarf. It will be much smaller than it is now, not quite as bright but twice as hot. Its matter (particles) will be more densely-packed together. ...
Sample Math problems
... These problems are meant to be representative of what you need to know for the final. They are not exactly the problems that will appear in the final exam, but they do require the same set of skills. They might not cover all the formulas and equations that we have seen in the class. I recommend goin ...
... These problems are meant to be representative of what you need to know for the final. They are not exactly the problems that will appear in the final exam, but they do require the same set of skills. They might not cover all the formulas and equations that we have seen in the class. I recommend goin ...
ASTR 101 Final Study Guide I received study guides for Chapters 1
... Gravity holds a star together, while pressure supports a star against gravity. Stars form from the matter in interstellar clouds, but also return much of that matter back to space once they live and die out. Interstellar matter is mostly hydrogen, with some helium as well as a tiny amount of silicat ...
... Gravity holds a star together, while pressure supports a star against gravity. Stars form from the matter in interstellar clouds, but also return much of that matter back to space once they live and die out. Interstellar matter is mostly hydrogen, with some helium as well as a tiny amount of silicat ...
Test 2 Review Topics
... 34. How does solar activity affect us on Earth? 35. How do stars produce photons? 36. What is the basic proton-proton chain? 37. What determines how long a star will live? Chapter 8: “Star Properties” 38. What is the only direct method for measuring distance? a. Sketch the system that shows this me ...
... 34. How does solar activity affect us on Earth? 35. How do stars produce photons? 36. What is the basic proton-proton chain? 37. What determines how long a star will live? Chapter 8: “Star Properties” 38. What is the only direct method for measuring distance? a. Sketch the system that shows this me ...
Part 2: Solar System Formation
... • Around the star Beta Pictoris a large disk of dust and gas has been observed. • The light from the star is much brighter than the disk so it had to be blocked for the disk to appear clearly. • Disks have been seen around other stars too including Vega. ...
... • Around the star Beta Pictoris a large disk of dust and gas has been observed. • The light from the star is much brighter than the disk so it had to be blocked for the disk to appear clearly. • Disks have been seen around other stars too including Vega. ...
Type II supernova
A Type II supernova (plural: supernovae or supernovas) results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, and no more than 40–50 times, the mass of the Sun (M☉) for this type of explosion. It is distinguished from other types of supernovae by the presence of hydrogen in its spectrum. Type II supernovae are mainly observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies.Stars generate energy by the nuclear fusion of elements. Unlike the Sun, massive stars possess the mass needed to fuse elements that have an atomic mass greater than hydrogen and helium, albeit at increasingly higher temperatures and pressures, causing increasingly shorter stellar life spans. The degeneracy pressure of electrons and the energy generated by these fusion reactions are sufficient to counter the force of gravity and prevent the star from collapsing, maintaining stellar equilibrium. The star fuses increasingly higher mass elements, starting with hydrogen and then helium, progressing up through the periodic table until a core of iron and nickel is produced. Fusion of iron or nickel produces no net energy output, so no further fusion can take place, leaving the nickel-iron core inert. Due to the lack of energy output allowing outward pressure, equilibrium is broken.When the mass of the inert core exceeds the Chandrasekhar limit of about 1.4 M☉, electron degeneracy alone is no longer sufficient to counter gravity and maintain stellar equilibrium. A cataclysmic implosion takes place within seconds, in which the outer core reaches an inward velocity of up to 23% of the speed of light and the inner core reaches temperatures of up to 100 billion kelvin. Neutrons and neutrinos are formed via reversed beta-decay, releasing about 1046 joules (100 foes) in a ten-second burst. The collapse is halted by neutron degeneracy, causing the implosion to rebound and bounce outward. The energy of this expanding shock wave is sufficient to accelerate the surrounding stellar material to escape velocity, forming a supernova explosion, while the shock wave and extremely high temperature and pressure briefly allow for theproduction of elements heavier than iron. Depending on initial size of the star, the remnants of the core form a neutron star or a black hole. Because of the underlying mechanism, the resulting nova is also described as a core-collapse supernova.There exist several categories of Type II supernova explosions, which are categorized based on the resulting light curve—a graph of luminosity versus time—following the explosion. Type II-L supernovae show a steady (linear) decline of the light curve following the explosion, whereas Type II-P display a period of slower decline (a plateau) in their light curve followed by a normal decay. Type Ib and Ic supernovae are a type of core-collapse supernova for a massive star that has shed its outer envelope of hydrogen and (for Type Ic) helium. As a result, they appear to be lacking in these elements.