Chapter 29
... The nebulae collapses upon itself and rotates. As it continues to contract it gains pressure and temperature until fusion begins ...
... The nebulae collapses upon itself and rotates. As it continues to contract it gains pressure and temperature until fusion begins ...
Integrative Studies 410 Our Place in the Universe
... The Standard Solar Model (SSM) • Sun is a gas ball of hydrogen & helium • Density and temperature increase towards center • Very hot & dense core produces all the energy by hydrogen nuclear fusion • Energy is released in the form of EM radiation and particles (neutrinos) • Energy transport well und ...
... The Standard Solar Model (SSM) • Sun is a gas ball of hydrogen & helium • Density and temperature increase towards center • Very hot & dense core produces all the energy by hydrogen nuclear fusion • Energy is released in the form of EM radiation and particles (neutrinos) • Energy transport well und ...
Lecture 13 (pdf from the powerpoint)
... • The length of time a star spends fusing hydrogen into helium is called its main sequence lifetime ...
... • The length of time a star spends fusing hydrogen into helium is called its main sequence lifetime ...
ASTR-1020: Astronomy II Course Lecture Notes - Faculty
... If stellar mass objects greater than 50 M do survive gravitational instabilities during birth, these objects would collapse very rapidly from protostar state and burn their thermonuclear fuel so quickly (i.e., within 10 million years) that few of these objects would be seen. When these hypermassive ...
... If stellar mass objects greater than 50 M do survive gravitational instabilities during birth, these objects would collapse very rapidly from protostar state and burn their thermonuclear fuel so quickly (i.e., within 10 million years) that few of these objects would be seen. When these hypermassive ...
The Life Cycle of Stars Webquest
... 1. In this webquest, you will learn how to identify stars by their magnitude, color, temperature, and spectral class. 2. You will investigate the process of nuclear fusion explained by Einstein's famous equation E = MC2 and learn how mass in the form of hydrogen atoms is converted to helium and caus ...
... 1. In this webquest, you will learn how to identify stars by their magnitude, color, temperature, and spectral class. 2. You will investigate the process of nuclear fusion explained by Einstein's famous equation E = MC2 and learn how mass in the form of hydrogen atoms is converted to helium and caus ...
HW11
... temperature. So they are on the right side of the diagram. But their luminosity is huge. This is because their radius is gigantic. 4) Understand spectral typing. Why the hydrogen lines become large as the surface temperature increases until they reach spectral type A. Then as the temperature increas ...
... temperature. So they are on the right side of the diagram. But their luminosity is huge. This is because their radius is gigantic. 4) Understand spectral typing. Why the hydrogen lines become large as the surface temperature increases until they reach spectral type A. Then as the temperature increas ...
PHYSICS 1500 - ASTRONOMY TOTAL: 100 marks Section A Please
... Scheat ( Pegasi) is a star of spectral class M2 and luminosity class II. Based on this information which of the following are true? I. Scheat has a surface temperature less than the sun. II. Scheat has a diameter that is greater than that of the sun. III. Scheat is more luminous than the sun. IV. S ...
... Scheat ( Pegasi) is a star of spectral class M2 and luminosity class II. Based on this information which of the following are true? I. Scheat has a surface temperature less than the sun. II. Scheat has a diameter that is greater than that of the sun. III. Scheat is more luminous than the sun. IV. S ...
Stars
... • Massive stars have short lives • End star life in brilliant explosions called supernova • Rare 1. Death is triggered when nuclear fuel is consumed 2. Star collapses 3. Implodes 4. Sends shock wave out from the stars interior, this destroys the star blasting the shell into space • None have been ob ...
... • Massive stars have short lives • End star life in brilliant explosions called supernova • Rare 1. Death is triggered when nuclear fuel is consumed 2. Star collapses 3. Implodes 4. Sends shock wave out from the stars interior, this destroys the star blasting the shell into space • None have been ob ...
final fate of a massive star
... in the USA. After many years, the prediction of white dwarfs was verified. It also then became known that stars three to five times the Sun give rise to what are called Neutron stars, just about ten kilometers in size, after causing a supernova explosion. ...
... in the USA. After many years, the prediction of white dwarfs was verified. It also then became known that stars three to five times the Sun give rise to what are called Neutron stars, just about ten kilometers in size, after causing a supernova explosion. ...
Physics 111 HW 23 - University of St. Thomas
... The bar has mass 50.0 g and is 100 cm in length. The bug jumps off in the horizontal direction, perpendicular to the bar, with a speed of 20.0 cm/s relative to the table. a) What is the angular speed of the bar just after the frisky insect leaps? b) What is the total kinetic energy of the system jus ...
... The bar has mass 50.0 g and is 100 cm in length. The bug jumps off in the horizontal direction, perpendicular to the bar, with a speed of 20.0 cm/s relative to the table. a) What is the angular speed of the bar just after the frisky insect leaps? b) What is the total kinetic energy of the system jus ...
Contemporary Physics - Department of Physics and Astronomy
... A supernova of type Ia, an explosion of a white dwarf star that occurs when it gathers sufficient mass from a nearby companion to go over a limiting mass for stability, is one of the best distance indicators we have. These stars reach a maximum luminosity with an absolute magnitude of about -19. Wha ...
... A supernova of type Ia, an explosion of a white dwarf star that occurs when it gathers sufficient mass from a nearby companion to go over a limiting mass for stability, is one of the best distance indicators we have. These stars reach a maximum luminosity with an absolute magnitude of about -19. Wha ...
sun elements
... any process that could explain the energy production of the Sun. •Even if a fire, such as those that occur on Earth, were as large as the Sun, the fire would consume the mass of the Sun in a few thousand years. ...
... any process that could explain the energy production of the Sun. •Even if a fire, such as those that occur on Earth, were as large as the Sun, the fire would consume the mass of the Sun in a few thousand 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.