Stars
... The key to locating the North Star in the night sky is to first find the Big Dipper, a constellation of stars known as Ursa Major.. The Big Dipper is perhaps the best known group of stars in the northern sky and is easy to distinguish from all others. Also known as the Great Bear, the Big Dipper is ...
... The key to locating the North Star in the night sky is to first find the Big Dipper, a constellation of stars known as Ursa Major.. The Big Dipper is perhaps the best known group of stars in the northern sky and is easy to distinguish from all others. Also known as the Great Bear, the Big Dipper is ...
answers2006_07_BC
... Type Ia supernovae all have very similar brightness, and are bright enough to be seen out to large redshifts, so can be used to check how the expansion of the universe changes with time. ...
... Type Ia supernovae all have very similar brightness, and are bright enough to be seen out to large redshifts, so can be used to check how the expansion of the universe changes with time. ...
s%nffi - mrtavares
... energy. As liydrogen is consumed, the product of this reaction-helium-forms the solar core, which continually grows in size. ...
... energy. As liydrogen is consumed, the product of this reaction-helium-forms the solar core, which continually grows in size. ...
Frontiers: Intermediate-Mass Black Holes For our final lecture we will
... that it is difficult to know what to expect in terms of a spectral or temporal signature. In fact, for many aspects of the observations (e.g., specific variations in the flux, and characteristics of the spectra), what we see is not at all what one would normally expect from beaming or super-Eddingto ...
... that it is difficult to know what to expect in terms of a spectral or temporal signature. In fact, for many aspects of the observations (e.g., specific variations in the flux, and characteristics of the spectra), what we see is not at all what one would normally expect from beaming or super-Eddingto ...
Super Giant
... Our galaxy is currently in the slow process of combining with the ____________ galaxy. What is the speed of light in miles? 186,000miles per second There are how many stars in our Milky Way galaxy? 219 BILLION STARS! What happens in the core of a star? Describe this process. Nuclear Fusion- 2 hydrog ...
... Our galaxy is currently in the slow process of combining with the ____________ galaxy. What is the speed of light in miles? 186,000miles per second There are how many stars in our Milky Way galaxy? 219 BILLION STARS! What happens in the core of a star? Describe this process. Nuclear Fusion- 2 hydrog ...
The Sun: Our Nearest Star
... and collide with nuclei. Occasionally they stick, making larger nuclei. If neutron flux is not too great, these heavier nuclei decay before more neutron captures. Technetium (Tc) has no stable isotopes (all decay). But it is found in the 99Tc has a half-life of 200,000 atmospheres of giant stars. ...
... and collide with nuclei. Occasionally they stick, making larger nuclei. If neutron flux is not too great, these heavier nuclei decay before more neutron captures. Technetium (Tc) has no stable isotopes (all decay). But it is found in the 99Tc has a half-life of 200,000 atmospheres of giant stars. ...
EX - Uplift North Hills Prep
... (a) Explain why a star having a mass of 50 times the solar mass would be expected to have a lifetime of many times less than that of the Sun. (a) The more massive stars will have much more nuclear material (initially hydrogen). Massive stars have greater gravity so equilibrium is reached at a highe ...
... (a) Explain why a star having a mass of 50 times the solar mass would be expected to have a lifetime of many times less than that of the Sun. (a) The more massive stars will have much more nuclear material (initially hydrogen). Massive stars have greater gravity so equilibrium is reached at a highe ...
Star Formation
... own sun, from SNe produced radioactive daughter products in meteorites) • Collapse raises density, core cannot radiate away heat gravitational collapse heat fast enough, and temp rises, until H fusion begins at 10 million K • Fusion provides pressure, balancing gravity, stabilizing star. • Star clus ...
... own sun, from SNe produced radioactive daughter products in meteorites) • Collapse raises density, core cannot radiate away heat gravitational collapse heat fast enough, and temp rises, until H fusion begins at 10 million K • Fusion provides pressure, balancing gravity, stabilizing star. • Star clus ...
Solutions for the Homework 6
... the result of the previous problem, show that the total kinetic energy of the electrons is now proportional to 1/R instead of 1/R2 . Argue that there is no stable equilibrium radius for such a star. Solution: From the result of the problem 7.22, the Fermi energy is changed and it depends on the V −1 ...
... the result of the previous problem, show that the total kinetic energy of the electrons is now proportional to 1/R instead of 1/R2 . Argue that there is no stable equilibrium radius for such a star. Solution: From the result of the problem 7.22, the Fermi energy is changed and it depends on the V −1 ...
Chapter 14 Stellar Corpses Stellar Corpses White Dwarfs White
... compress their cores so much that no pressure is capable of supporting it – a black hole results • A black hole is an “object” (region of space) that has an escape velocity that exceeds the speed of light – hence the name – Using the equation for the escape velocity at an object’s surface, equating ...
... compress their cores so much that no pressure is capable of supporting it – a black hole results • A black hole is an “object” (region of space) that has an escape velocity that exceeds the speed of light – hence the name – Using the equation for the escape velocity at an object’s surface, equating ...
Journey to the Stars: Activities for Grades 9-12
... Have students read this online article to learn how light transmits information about the composition of distant celestial objects. These objects are so distant that even if we could travel at the speed of light, it would take us thousands of years to reach them. Ask students: What types of informat ...
... Have students read this online article to learn how light transmits information about the composition of distant celestial objects. These objects are so distant that even if we could travel at the speed of light, it would take us thousands of years to reach them. Ask students: What types of informat ...
Introduction This book will teach you all you need to know about the
... nucleus is bothered by neutrons. Uranium and plutonium are the most common fissionable elements. When one fission reaction occurs it sets off several other fission reaction, which then those set off other fission reactions and it jus keeps going like that. Below is an example of fission. The next on ...
... nucleus is bothered by neutrons. Uranium and plutonium are the most common fissionable elements. When one fission reaction occurs it sets off several other fission reaction, which then those set off other fission reactions and it jus keeps going like that. Below is an example of fission. The next on ...
Our Star - U of L Class Index
... Note: This is far beyond the predicted lifetime of the Sun. It is estimated that the Sun will “only” last another 5-6 billion years. ...
... Note: This is far beyond the predicted lifetime of the Sun. It is estimated that the Sun will “only” last another 5-6 billion years. ...
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.