Friday, January 27, 2017 First exam a week from today. Review
... Magnesium, Silicon, Calcium, finally Iron. The intermediate-mass elements are produced in the star before the explosion and then expelled into space. In exploding white dwarfs (arising in stars with mass less than about 8 times the Sun), the core is composed of Carbon and Oxygen, and the explosion c ...
... Magnesium, Silicon, Calcium, finally Iron. The intermediate-mass elements are produced in the star before the explosion and then expelled into space. In exploding white dwarfs (arising in stars with mass less than about 8 times the Sun), the core is composed of Carbon and Oxygen, and the explosion c ...
WebQuest-The-Life-Cycle-of-Stars-1
... Task #5: Life Cycle of Stars Go to the website http://map.gsfc.nasa.gov/universe/rel_stars.html. Read the short section on “Where are stars born” and see pictures of the protostars of M16: The Eagle Nebula and other nebulae on this page. Continue by reading up on Main Sequence Stars and find out how ...
... Task #5: Life Cycle of Stars Go to the website http://map.gsfc.nasa.gov/universe/rel_stars.html. Read the short section on “Where are stars born” and see pictures of the protostars of M16: The Eagle Nebula and other nebulae on this page. Continue by reading up on Main Sequence Stars and find out how ...
lecture23
... All stars in a cluster are of about the same age. Clusters therefore are natural laboratory in which mass, rather than age, of stars is only significant variable. ...
... All stars in a cluster are of about the same age. Clusters therefore are natural laboratory in which mass, rather than age, of stars is only significant variable. ...
Stars and Galaxies
... Fusion of hydrogen occurs in star cores releasing huge amounts of energy Evolution of stars A nebula contracts and breaks apart from the instability caused by gravity Temperatures in each nebula chunk increase as particles move closer together At 10 million K fusion begins and energy from a n ...
... Fusion of hydrogen occurs in star cores releasing huge amounts of energy Evolution of stars A nebula contracts and breaks apart from the instability caused by gravity Temperatures in each nebula chunk increase as particles move closer together At 10 million K fusion begins and energy from a n ...
Slide 1
... A Hertzprung-Russell diagram is a very useful illustration of the relationship between various key stellar properties, namely the luminosity and the effective temperature (related to both spectral type and colour) of a range of stars. An example is shown in Figure 1 (A). Stars at the bottom right ar ...
... A Hertzprung-Russell diagram is a very useful illustration of the relationship between various key stellar properties, namely the luminosity and the effective temperature (related to both spectral type and colour) of a range of stars. An example is shown in Figure 1 (A). Stars at the bottom right ar ...
Stars and Sun
... Temperatures rise and cause atoms in cloud to merge Process called fusion and changes matter to the energy that powers the star ...
... Temperatures rise and cause atoms in cloud to merge Process called fusion and changes matter to the energy that powers the star ...
January 2006
... Physics Coffee is every Wednesday, 3:30 pm Open to the public, everyone welcome! Location: across the hall, Science 256 ...
... Physics Coffee is every Wednesday, 3:30 pm Open to the public, everyone welcome! Location: across the hall, Science 256 ...
Document
... and low-mass main sequence (hydrogen burning) stars like the Sun. • Protostars forms from molecular clouds. When a portion of a molecular cloud reaches a critical mass it begins to collapse under its own gravity. The initial collapse takes about 100,000 years. After that time the star reaches a surf ...
... and low-mass main sequence (hydrogen burning) stars like the Sun. • Protostars forms from molecular clouds. When a portion of a molecular cloud reaches a critical mass it begins to collapse under its own gravity. The initial collapse takes about 100,000 years. After that time the star reaches a surf ...
Powerpoint for today
... billion years ago. As Milky Way ages, the abundances of elements compared to H in gas and new stars are increasing due to fusion and supernovae. Elements up to iron (56Fe, 26 p + 30 n in nucleus) produced by steady fusion (less abundant elements we didn’t discuss, like Cl, Na, made in reactions that ...
... billion years ago. As Milky Way ages, the abundances of elements compared to H in gas and new stars are increasing due to fusion and supernovae. Elements up to iron (56Fe, 26 p + 30 n in nucleus) produced by steady fusion (less abundant elements we didn’t discuss, like Cl, Na, made in reactions that ...
The Earth in Space Scientific evidence indicates the universe is
... been continually expanding at an increasing rate since its formation about 13.7 billion years ago. E5.1A Describe the position and motion of our solar system in our galaxy and the overall scale, structure, and age of the universe. E5.2 The Sun Stars, including the Sun, transform matter into energy i ...
... been continually expanding at an increasing rate since its formation about 13.7 billion years ago. E5.1A Describe the position and motion of our solar system in our galaxy and the overall scale, structure, and age of the universe. E5.2 The Sun Stars, including the Sun, transform matter into energy i ...
Chapter 15. The Chandrasekhar Limit, Iron-56 and Core
... momentum and magnetic flux, greatly intensifies the magnetic field of the neutron star over what existed in the star prior to the core collapse. Also the star spins much faster (about 30 times per second when first formed). If the magnetic and rotation axes are even slightly misaligned (as they are ...
... momentum and magnetic flux, greatly intensifies the magnetic field of the neutron star over what existed in the star prior to the core collapse. Also the star spins much faster (about 30 times per second when first formed). If the magnetic and rotation axes are even slightly misaligned (as they are ...
Big bang and Stars
... their original mass After they spend their life as main sequence star …. Sun size > expand to red giant in about 5 billion years > white dwarf > black dwarf Super giant > supernova > very high mass – black hole high mass – neutron star ...
... their original mass After they spend their life as main sequence star …. Sun size > expand to red giant in about 5 billion years > white dwarf > black dwarf Super giant > supernova > very high mass – black hole high mass – neutron star ...
Name Date Period ______ 30.1 Characteristics of Stars Definitions
... 19. What are circumpolar stars? What is one example? ...
... 19. What are circumpolar stars? What is one example? ...
What is a Star?
... solar masses it contracts to become a a tiny, very dense Neutron Star. If the core is much greater than 3 solar masses, the core contracts to become a Black Hole. ...
... solar masses it contracts to become a a tiny, very dense Neutron Star. If the core is much greater than 3 solar masses, the core contracts to become a Black Hole. ...
Introduction to the HR Diagram
... located in the upper right-hand corner of the H-R diagram. As the central core of a main sequence star with a mass from ~0.8 to 8 solar masses runs out of hydrogen, radiation pressure no longer balances gravity and the star begins to collapse. There is still hydrogen in the outer layers surrounding ...
... located in the upper right-hand corner of the H-R diagram. As the central core of a main sequence star with a mass from ~0.8 to 8 solar masses runs out of hydrogen, radiation pressure no longer balances gravity and the star begins to collapse. There is still hydrogen in the outer layers surrounding ...
Hertzsprung Russell diagram
... the bottom right. Some stars, like the supergiants are quite cool but because of their enormous size they are in the top right of the diagram. On the other hand white dwarfs are hot small stars and so appear to the bottom left. There is a band of stars that runs from the top left to the bottom right ...
... the bottom right. Some stars, like the supergiants are quite cool but because of their enormous size they are in the top right of the diagram. On the other hand white dwarfs are hot small stars and so appear to the bottom left. There is a band of stars that runs from the top left to the bottom right ...
Stars are classified by how hot they are (temperature)
... Due to Earth's rotation, we see the sun rise and set, and stars come and go in the night Stars do move in space, but because they are so distant, their motion is hard for us to ...
... Due to Earth's rotation, we see the sun rise and set, and stars come and go in the night Stars do move in space, but because they are so distant, their motion is hard for us to ...
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.