Spectra of Star Clusters
... • The overall range of stellar masses runs from 0.08 times the mass of the Sun to about 100 times the mass of the Sun. ...
... • The overall range of stellar masses runs from 0.08 times the mass of the Sun to about 100 times the mass of the Sun. ...
Astr. 170B1 Due Feb. 5 Professor Rieke and TA Melissa Halford
... a. They are jumping from a lower to a higher level b. they are jumping from higher to lower c. They are leaving the cloud d. We cannot know how they are moving e. They are jumping from a lower to a higher level and then eventually falling back to the lower leve ...
... a. They are jumping from a lower to a higher level b. they are jumping from higher to lower c. They are leaving the cloud d. We cannot know how they are moving e. They are jumping from a lower to a higher level and then eventually falling back to the lower leve ...
The star Epsilon UMa, or more commonly known as Alioth
... and the approximate surface temperature ranges from 7,500 to 11,000 degrees Kelvin. The average luminosity of these stars is around 80 solar luminosity (1 solar luminosity equaling 3.83 x 1033 ergs/s), the average mass is approximately 3.2 solar masses (1 solar mass equaling 1.989 x 1030 kg) and the ...
... and the approximate surface temperature ranges from 7,500 to 11,000 degrees Kelvin. The average luminosity of these stars is around 80 solar luminosity (1 solar luminosity equaling 3.83 x 1033 ergs/s), the average mass is approximately 3.2 solar masses (1 solar mass equaling 1.989 x 1030 kg) and the ...
Today in Astronomy 142
... Beyond the Chandrasekhar mass: neutron stars A dead star more massive than 1.4 M⊙ simply cannot be supported by electron degeneracy pressure; add a little too much mass and it will collapse gravitationally. ! During the collapse, the extra energy liberated from gravity, and the high density, can he ...
... Beyond the Chandrasekhar mass: neutron stars A dead star more massive than 1.4 M⊙ simply cannot be supported by electron degeneracy pressure; add a little too much mass and it will collapse gravitationally. ! During the collapse, the extra energy liberated from gravity, and the high density, can he ...
Chapter21
... In most other introductory astronomy textbooks, binary stars are covered in a piecemeal fashion in several different chapters. There are several reasons why I decided to cover binary stars in a single coherent chapter. First, most stars are in binary or multiple systems, so it isn’t reasonable to tr ...
... In most other introductory astronomy textbooks, binary stars are covered in a piecemeal fashion in several different chapters. There are several reasons why I decided to cover binary stars in a single coherent chapter. First, most stars are in binary or multiple systems, so it isn’t reasonable to tr ...
Assignment 7 - Department of Physics and Astronomy
... e. the astronomer must be making up stories to impress his colleagues; there is no way to measure the speed with which stars move away or toward us. ____ 12. A graduate student has spent a whole year doing a careful analysis of the spectrum of a star. While she has found lines from many elements, ...
... e. the astronomer must be making up stories to impress his colleagues; there is no way to measure the speed with which stars move away or toward us. ____ 12. A graduate student has spent a whole year doing a careful analysis of the spectrum of a star. While she has found lines from many elements, ...
Rogava_Course_-_First_lecture
... impact on each other, stars essentially evolve separately. • Semidetached binary stars: one of the components fills its Roche lobe and the other does not. Gas from the surface of the Roche lobe filling component (donor) is transferred to the other, accreting star. The mass transfer dominates the evo ...
... impact on each other, stars essentially evolve separately. • Semidetached binary stars: one of the components fills its Roche lobe and the other does not. Gas from the surface of the Roche lobe filling component (donor) is transferred to the other, accreting star. The mass transfer dominates the evo ...
English Summary
... hundred billion stars in a galaxy they occupy a negligible volume of space compared to their vast distances. This space is called the interstellar medium. It is mostly empty, but one can also find clouds of dense6 gas called molecular regions. It is in these places where new stars are born. This den ...
... hundred billion stars in a galaxy they occupy a negligible volume of space compared to their vast distances. This space is called the interstellar medium. It is mostly empty, but one can also find clouds of dense6 gas called molecular regions. It is in these places where new stars are born. This den ...
Lecture 13 - Star Formation
... Molecular clouds • Dark nebula are usually molecular clouds • Molecular clouds are relatively dense and are very cold, often only 10 K. • Giant molecular clouds can contain as much as 104 solar masses of gas and be 10 light ...
... Molecular clouds • Dark nebula are usually molecular clouds • Molecular clouds are relatively dense and are very cold, often only 10 K. • Giant molecular clouds can contain as much as 104 solar masses of gas and be 10 light ...
Other burning stages - Michigan State University
... Often, some, but not all nuclei are in equilibrium with protons and neutrons (and with each other). A group of nuclei in equilibrium is called an equilibrium cluster. Because of reactions involving single nucleons or alpha particles being the mediators of the equilibrium, neighboring nuclei tend to ...
... Often, some, but not all nuclei are in equilibrium with protons and neutrons (and with each other). A group of nuclei in equilibrium is called an equilibrium cluster. Because of reactions involving single nucleons or alpha particles being the mediators of the equilibrium, neighboring nuclei tend to ...
Neutron stars and quark stars - Goethe
... • super-Eddington luminosity from bare, hot strange stars (Page and Usov, 2002) • conversion of neutron stars to strange stars (explosive events!) ...
... • super-Eddington luminosity from bare, hot strange stars (Page and Usov, 2002) • conversion of neutron stars to strange stars (explosive events!) ...
Evolution and nucleosynthesis of extremely metal
... high neutron flux in the He-rich convective region, which we call a neutron “superburst”. The neutron flux for the superburst is primarily supplied by 13 C(α,n)16 O reactions occurring at the base of the HeCZ. The 13 C for this reaction is produced as a consequence of the proton ingestion – it is a ...
... high neutron flux in the He-rich convective region, which we call a neutron “superburst”. The neutron flux for the superburst is primarily supplied by 13 C(α,n)16 O reactions occurring at the base of the HeCZ. The 13 C for this reaction is produced as a consequence of the proton ingestion – it is a ...
Galaxies and Stars
... 66. Base your answer to the following question on the diagram below, which shows an inferred sequence in which our solar system formed from a giant interstellar cloud of gas and debris. Stage A shows the collapse of the gas cloud, stage B shows its flattening, and stage C shows the sequence that le ...
... 66. Base your answer to the following question on the diagram below, which shows an inferred sequence in which our solar system formed from a giant interstellar cloud of gas and debris. Stage A shows the collapse of the gas cloud, stage B shows its flattening, and stage C shows the sequence that le ...
Chapter 30 Notes
... • After the supergiant stage, the star collapses, producing such high temperatures that nuclear fusion begins again. • When nuclear fusion stops, the star’s core begins to collapse under its own gravity. This causes the outer layers to explode outward with tremendous force. Neutron Stars neutron sta ...
... • After the supergiant stage, the star collapses, producing such high temperatures that nuclear fusion begins again. • When nuclear fusion stops, the star’s core begins to collapse under its own gravity. This causes the outer layers to explode outward with tremendous force. Neutron Stars neutron sta ...
Stars: flux, luminosity, color, and temperature
... Absolute magnitude • The magnitude of a star gives it brightness or flux when observed from Earth. • To talk about the properties of star, independent of how far they happen to be from Earth, we use “absolute magnitude”. • Absolute magnitude is the magnitude that a star would have viewed from a dis ...
... Absolute magnitude • The magnitude of a star gives it brightness or flux when observed from Earth. • To talk about the properties of star, independent of how far they happen to be from Earth, we use “absolute magnitude”. • Absolute magnitude is the magnitude that a star would have viewed from a dis ...
Black Hole Sun: A Total Eclipse Free Public Lecture about Eclipses
... Å angstrom (10-10m) • Wave moves at speed of light c. • Frequency is rate at which crests pass. • f = c/λ • Cycles/second; Hertz ...
... Å angstrom (10-10m) • Wave moves at speed of light c. • Frequency is rate at which crests pass. • f = c/λ • Cycles/second; Hertz ...
J fusion kWhr fusion fusions customer kg customer kg kg fusion
... 1000 kg). How many of these ships would have to be fused each second to supply Sol’s energy (IF they were pure hydrogen … not a great shipbuilding material, but hey, this is the ivory tower, eh?)? 1. Find the mass of an aircraft carrier in kg (keep 4 significant figures) ...
... 1000 kg). How many of these ships would have to be fused each second to supply Sol’s energy (IF they were pure hydrogen … not a great shipbuilding material, but hey, this is the ivory tower, eh?)? 1. Find the mass of an aircraft carrier in kg (keep 4 significant figures) ...
Slides from the talk
... The de Broglie wavelength is much shorter than the size of the nuclei and the form factor kills the enhancement of the cross section due to the coherence. ...
... The de Broglie wavelength is much shorter than the size of the nuclei and the form factor kills the enhancement of the cross section due to the coherence. ...
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.