Stellar Evolution
... diagram will move to the left as it heats up but wander up and down somewhat as its size shrinks. This process takes about 50 million years for a star like the sun, but may take a much shorter time for a more massive star since there will be more gravity. A ten solar mass star will only spend about ...
... diagram will move to the left as it heats up but wander up and down somewhat as its size shrinks. This process takes about 50 million years for a star like the sun, but may take a much shorter time for a more massive star since there will be more gravity. A ten solar mass star will only spend about ...
Exploring the Universe
... 2. When a protostar is dense & hot enough it will begin fusion. Nuclear fusion begins to take control over the gravity and the star begins to stabilize. a. Fusion reactions in the core produce an outward force that balances the inward force of gravity ...
... 2. When a protostar is dense & hot enough it will begin fusion. Nuclear fusion begins to take control over the gravity and the star begins to stabilize. a. Fusion reactions in the core produce an outward force that balances the inward force of gravity ...
Stellar Evolution (Powerpoint) 17
... • If the white dwarf is close to the 1.4 solar mass upper limit that electron degeneracy can support… • The added mass could push it past the limit before it gets hot enough to flash off • Then, star collapses under the weight and because it is electron degenerate, energy created will not expand the ...
... • If the white dwarf is close to the 1.4 solar mass upper limit that electron degeneracy can support… • The added mass could push it past the limit before it gets hot enough to flash off • Then, star collapses under the weight and because it is electron degenerate, energy created will not expand the ...
Planetary Nebulae – White dwarfs
... • May burn up to carbon but do not have enough mass to get temperatures high enough to go any higher up the periodic table • Degeneracy pressure stops the core from collapsing and heating enough: particles are squashed together as much as possible • End their lives with planetary nebulae, white d ...
... • May burn up to carbon but do not have enough mass to get temperatures high enough to go any higher up the periodic table • Degeneracy pressure stops the core from collapsing and heating enough: particles are squashed together as much as possible • End their lives with planetary nebulae, white d ...
1 - Physics
... The core collapses because the core can no longer generate energy from fusion (fusing Iron takes energy and does not generate energy). Therefore gravity starts to win and the core shrinks. ...
... The core collapses because the core can no longer generate energy from fusion (fusing Iron takes energy and does not generate energy). Therefore gravity starts to win and the core shrinks. ...
Unit 11 Guide: Concepts of Earth Science Stars, Galaxies, and the
... 4. Compare and contrast the apparent and actual motion of stars. How can scientists know if a star or galaxy is moving toward or away from Earth? 5. What is the difference between absolute and apparent magnitude? What is luminosity? 6. What are the three types of spectra? How can scientists use abso ...
... 4. Compare and contrast the apparent and actual motion of stars. How can scientists know if a star or galaxy is moving toward or away from Earth? 5. What is the difference between absolute and apparent magnitude? What is luminosity? 6. What are the three types of spectra? How can scientists use abso ...
universe_pp_4 - Cobb Learning
... •Contains hundreds of billions of stars •Traveling at the speed of light-it would take ...
... •Contains hundreds of billions of stars •Traveling at the speed of light-it would take ...
Integrative Studies 410 Our Place in the Universe
... • increasing temperature at core slows contraction – Luminosity about 1000 times that of the sun – Duration ~ 1 million years – Temperature ~ 1 million K at core, 3,000 K at surface • Still too cool for nuclear fusion! ...
... • increasing temperature at core slows contraction – Luminosity about 1000 times that of the sun – Duration ~ 1 million years – Temperature ~ 1 million K at core, 3,000 K at surface • Still too cool for nuclear fusion! ...
Supernova
... • Sun-like stars (M< 9 Msolar) stop producing energy with Shell Helium Burning and leave behind a carbon core (White Dwarf). • Stars more massive continue to fuse heavier elements in their cores as they evolve. Carbon burning at 600 Million K Neon burning at 1.2 Billion K Oxygen Burning at 1.5 Billi ...
... • Sun-like stars (M< 9 Msolar) stop producing energy with Shell Helium Burning and leave behind a carbon core (White Dwarf). • Stars more massive continue to fuse heavier elements in their cores as they evolve. Carbon burning at 600 Million K Neon burning at 1.2 Billion K Oxygen Burning at 1.5 Billi ...
Life Cycle of a Star
... • A contracting cloud of gas and dust • Pressure and heat start nuclear fusion ...
... • A contracting cloud of gas and dust • Pressure and heat start nuclear fusion ...
Jeopardy - Two Rivers High School
... Stars are found in galaxies. What color are stars that are old and have low temperatures? ...
... Stars are found in galaxies. What color are stars that are old and have low temperatures? ...
Notes: Star Formation
... • Brown Dwarfs don’t get hot enough to start fusion. • They shine dimly, but slowly cool off. ...
... • Brown Dwarfs don’t get hot enough to start fusion. • They shine dimly, but slowly cool off. ...
Life Cycle of a Star
... • A contracting cloud of gas and dust • Pressure and heat start nuclear fusion ...
... • A contracting cloud of gas and dust • Pressure and heat start nuclear fusion ...
INV 12B MOTION WITH CHANGING SPEED DRY LAB DATA
... 3. How does the sun compare to the other stars on the main sequence? (Hint: The sun’s color is …..What part of the main sequence is it in – upper left, lower left, etc.?) ...
... 3. How does the sun compare to the other stars on the main sequence? (Hint: The sun’s color is …..What part of the main sequence is it in – upper left, lower left, etc.?) ...
Coursework 7 File
... of the Sun is approximately T = 1.55 × 107 K. You should note that the electrostatic force attempts to repel the particles as they approach one another, and the associated electrostatic potential energy is given by Epe = −q1 q2 /(4π0 d), where d is the distance between the charges q1 and q2 . 2. Th ...
... of the Sun is approximately T = 1.55 × 107 K. You should note that the electrostatic force attempts to repel the particles as they approach one another, and the associated electrostatic potential energy is given by Epe = −q1 q2 /(4π0 d), where d is the distance between the charges q1 and q2 . 2. Th ...
Star
... -Since different elements absorb different wavelengths of light, elements can be determined. -Stars are made up of gas elements. (Hydrogen is the most common!) ...
... -Since different elements absorb different wavelengths of light, elements can be determined. -Stars are made up of gas elements. (Hydrogen is the most common!) ...
ASTRONOMY 157 – Stars and Galaxies - Syllabus
... Nuclear fusion cycles, total energy production, star lifetime estimation; photon random walk calculation ...
... Nuclear fusion cycles, total energy production, star lifetime estimation; photon random walk calculation ...
The Sun is a mass of Incandescent Gas
... Some are 50x that of the Sun! Massive stars evolve in a similar way to a small stars until it reaches its main sequence stage (see small stars, stages 1-4). The stars shine steadily until the hydrogen has fused to form helium ( it takes billions of years in a small star, but only millions in a massi ...
... Some are 50x that of the Sun! Massive stars evolve in a similar way to a small stars until it reaches its main sequence stage (see small stars, stages 1-4). The stars shine steadily until the hydrogen has fused to form helium ( it takes billions of years in a small star, but only millions in a massi ...
White Dwarfs and Neutron Stars
... • Is no longer actively creating energy through thermonuclear fusion • Peak emission in Ultraviolet • Radius comparable to Earth’s • Mass limit of about 1.4 solar masses • Can explode into novae and supernovae ...
... • Is no longer actively creating energy through thermonuclear fusion • Peak emission in Ultraviolet • Radius comparable to Earth’s • Mass limit of about 1.4 solar masses • Can explode into novae and supernovae ...
Star Life Cycles Stellar Nebula
... Star spends more than 90% of its life Our sun is in this stage ...
... Star spends more than 90% of its life Our sun is in this stage ...
Stars
... A ‘Star’ is a large celestial body composed of gravitationally contained hot gases emitting electromagnetic radiation, especially light, as a result of nuclear reactions inside the star. The sun is a star. With the exception of the sun, stars appear to be fixed, maintaining the same pattern in the s ...
... A ‘Star’ is a large celestial body composed of gravitationally contained hot gases emitting electromagnetic radiation, especially light, as a result of nuclear reactions inside the star. The sun is a star. With the exception of the sun, stars appear to be fixed, maintaining the same pattern in the s ...
File
... C. Iron is the most stable element 1. No natural fission or fusion 2. Photodisintegration of core 3. Quickly collapses D. e’s & protons fuse into neutrons E. Neutron degeneracy prevents total collapse F. Collapse rebounds in < 1 sec. ...
... C. Iron is the most stable element 1. No natural fission or fusion 2. Photodisintegration of core 3. Quickly collapses D. e’s & protons fuse into neutrons E. Neutron degeneracy prevents total collapse F. Collapse rebounds in < 1 sec. ...
Supernovae Type II
... 7. The bounce sends a shock wave outward at high velocity, blowing out the remaining stellar atmosphere in the process. Once the shock reaches the outer atmosphere, the photons emitted by recombination, powered by the shock itself and by subsequent nuclear decays, become the visible supernova explos ...
... 7. The bounce sends a shock wave outward at high velocity, blowing out the remaining stellar atmosphere in the process. Once the shock reaches the outer atmosphere, the photons emitted by recombination, powered by the shock itself and by subsequent nuclear decays, become the visible supernova explos ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.