L19-Review2
... study at Florida State University indicates that people do not make good decisions on low blood sugar. Eat before exams ...
... study at Florida State University indicates that people do not make good decisions on low blood sugar. Eat before exams ...
chapter14 - Empyrean Quest Publishers
... randomly bouncing (every few cm) and absorbed and reemitted photons. ‘RANDOM WALK’ takes millions of ...
... randomly bouncing (every few cm) and absorbed and reemitted photons. ‘RANDOM WALK’ takes millions of ...
25 Study Guide
... (A) Explosion; atoms form; stars form; all matter concentrated at a single point. (B) All matter concentrated at a single point; explosion; atoms form; stars form. (C) Explosion; stars form; all matter concentrated at a single point; atoms form. (D) Stars form; atoms form; all matter concentrated at ...
... (A) Explosion; atoms form; stars form; all matter concentrated at a single point. (B) All matter concentrated at a single point; explosion; atoms form; stars form. (C) Explosion; stars form; all matter concentrated at a single point; atoms form. (D) Stars form; atoms form; all matter concentrated at ...
Lecture 19: Low
... • Continue with life of a lowlow-mass star (like the Sun) after exhausting H in core -- post MS • Red giant (RG I) phase, with H shell burning • Helium flash goes off in shrinking degenerate core: horizontal branch star with He core burning • Double shell burning (H and He) yields red supergiant (RG ...
... • Continue with life of a lowlow-mass star (like the Sun) after exhausting H in core -- post MS • Red giant (RG I) phase, with H shell burning • Helium flash goes off in shrinking degenerate core: horizontal branch star with He core burning • Double shell burning (H and He) yields red supergiant (RG ...
chapter_5_lecture_notes
... Copernicus- Proposed a heliocentric, or sun-centered, model of the solar system He determined that the sun was at the center of our solar system and that all the planets---including Earth---revolved around the sun. ...
... Copernicus- Proposed a heliocentric, or sun-centered, model of the solar system He determined that the sun was at the center of our solar system and that all the planets---including Earth---revolved around the sun. ...
AST301.Ch22.NeutGammBH - University of Texas Astronomy
... (closely related to x-ray bursters, which may be on their way to becoming millisecond pulsars). See Fig. 22.10. Pulsar planets—1992: Pulse period of a millisecond pulsar found to vary periodically planet in orbit around pulsar. Pulses arise earlier and later, depending on what part of the orbit th ...
... (closely related to x-ray bursters, which may be on their way to becoming millisecond pulsars). See Fig. 22.10. Pulsar planets—1992: Pulse period of a millisecond pulsar found to vary periodically planet in orbit around pulsar. Pulses arise earlier and later, depending on what part of the orbit th ...
Stars - Madison County Schools
... • Most average stars will blow away their outer atmospheres to form a planetary nebula • Their cores will remain behind and burn as a white dwarf until they cool down • What will be left is a dark ball of matter known as a black dwarf ...
... • Most average stars will blow away their outer atmospheres to form a planetary nebula • Their cores will remain behind and burn as a white dwarf until they cool down • What will be left is a dark ball of matter known as a black dwarf ...
The Milky Way
... What is its Luminosity? • L = 4x 3.14 x (7 x 10 8)2 x 6 x 108 (6000)4 = 5 x 1026 Watts • Compare with 40 watts light bulb ...
... What is its Luminosity? • L = 4x 3.14 x (7 x 10 8)2 x 6 x 108 (6000)4 = 5 x 1026 Watts • Compare with 40 watts light bulb ...
Stars Study Guide KEY
... 5. Describe a “mature star”. (What is happening at its core? What is it “giving off”?) Nuclear fusion is happening in the core of a mature star. It is giving off light and heat. 6. Tell how low mass stars are similar to high mass stars. All stars begin in a nebula, are made of matter, burn due to nu ...
... 5. Describe a “mature star”. (What is happening at its core? What is it “giving off”?) Nuclear fusion is happening in the core of a mature star. It is giving off light and heat. 6. Tell how low mass stars are similar to high mass stars. All stars begin in a nebula, are made of matter, burn due to nu ...
Big Bang and Life Cycle of Stars
... As a star burns up its fuel supply of hydrogen, gravity increases and the core starts to shrink. - Core temperature heats up and fusion begins, the outer region of the star expands. - This star then cools to red, and is so named as a red giant - When the collapsing core gets hot enough to process he ...
... As a star burns up its fuel supply of hydrogen, gravity increases and the core starts to shrink. - Core temperature heats up and fusion begins, the outer region of the star expands. - This star then cools to red, and is so named as a red giant - When the collapsing core gets hot enough to process he ...
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.