Chapter 14
... High Mass Stars – Less than 100 M on Main Sequence – Become Neutron Stars (1.4M < M < 3M) » Neutron Degeneracy Pressure ...
... High Mass Stars – Less than 100 M on Main Sequence – Become Neutron Stars (1.4M < M < 3M) » Neutron Degeneracy Pressure ...
The H-R Diagram
... 0.54 solar mass White Dwarf: final state Notice the sun will lose ~half its mass before ending as a white dwarf • Animated GIF of HR evolution ...
... 0.54 solar mass White Dwarf: final state Notice the sun will lose ~half its mass before ending as a white dwarf • Animated GIF of HR evolution ...
Stellar Evolution: the Death of Stars
... expel most stellar material outward • Shock wave produces a series of nuclear reaction, the only place elements heavier than iron (such as silver, gold) are produced in the universe ...
... expel most stellar material outward • Shock wave produces a series of nuclear reaction, the only place elements heavier than iron (such as silver, gold) are produced in the universe ...
White Dwarfs
... Eventually at ρ greater than about 10 7 g cm −3 electrons in the central part of the white dwarf start to move close to the speed of light. As the mass continues to grow, a larger fraction of the star is supported by relativistic electron degeneracy pressure. Consider the limit: GM ρ ...
... Eventually at ρ greater than about 10 7 g cm −3 electrons in the central part of the white dwarf start to move close to the speed of light. As the mass continues to grow, a larger fraction of the star is supported by relativistic electron degeneracy pressure. Consider the limit: GM ρ ...
Section 25.2 Stellar Evolution
... Match each death description with its star. Death Description 7. forms a red giant, which then collapses into a red dwarf and forms a planetary nebula 8. blows up in a supernova explosion 9. does not form a red giant; collapses directly into a white dwarf ...
... Match each death description with its star. Death Description 7. forms a red giant, which then collapses into a red dwarf and forms a planetary nebula 8. blows up in a supernova explosion 9. does not form a red giant; collapses directly into a white dwarf ...
Astronomy 103: Midterm 2 Answers Correct answer in bold
... 28. The planets Londinium and Bellerophon orbit a star called the White Sun. Londinium is 1 AU from the star, and Bellerophon is 10 AU away. The brightness of light from the White Sun on Londinium is about 100 watt/meter2. What is the brightness of light from the White Sun on Bellerophon? ...
... 28. The planets Londinium and Bellerophon orbit a star called the White Sun. Londinium is 1 AU from the star, and Bellerophon is 10 AU away. The brightness of light from the White Sun on Londinium is about 100 watt/meter2. What is the brightness of light from the White Sun on Bellerophon? ...
Lecture 10: Stellar Evolution
... • Star clusters are particularly useful because they contain stars of different mass that were born about the same time ...
... • Star clusters are particularly useful because they contain stars of different mass that were born about the same time ...
Stars off the Main Sequence - ScienceEducationatNewPaltz
... like our Sun consumes all hydrogen in its’ core, fusion stops No longer generates outward pressure to counteract inward pressure Outer shell of H around core ignites, prolonging life of star ...
... like our Sun consumes all hydrogen in its’ core, fusion stops No longer generates outward pressure to counteract inward pressure Outer shell of H around core ignites, prolonging life of star ...
The Sun - Center for Astrophysics and Space Astronomy CASA
... (On border between fusion and fission) Develops degenerate iron core than cannot flash Just gets hotter and heavier down in the middle of the star ...
... (On border between fusion and fission) Develops degenerate iron core than cannot flash Just gets hotter and heavier down in the middle of the star ...
Answers
... has been exhausted, leaving a high temperature, degenerate core as a white dwarf star. The timescale of helium fusion in a sun-like star is about 10% of the hydrogen burning phase, for the sun about 109 years. In high mass (> about 8 solar masses), fusion proceeds further, producing most elements of ...
... has been exhausted, leaving a high temperature, degenerate core as a white dwarf star. The timescale of helium fusion in a sun-like star is about 10% of the hydrogen burning phase, for the sun about 109 years. In high mass (> about 8 solar masses), fusion proceeds further, producing most elements of ...
The Hubble Space Telescope
... and debris from the disk eventually nuclear fusion occurs and a STAR is BORN Heat and radiation create a stellar wind sweeping away lose matter, but some debris remains eventually clumping together to become PLANETS ...
... and debris from the disk eventually nuclear fusion occurs and a STAR is BORN Heat and radiation create a stellar wind sweeping away lose matter, but some debris remains eventually clumping together to become PLANETS ...
Document
... Step 2: Out of the nebula a protostar forms Step 3: When nuclear fusion begins the protostar changes to a star Step4: The star will spend 90% of its life in the main-sequence Step5: As the star gets older nuclear fusion slows and the star expands and cools forming a red giant Step 6: Once the red gi ...
... Step 2: Out of the nebula a protostar forms Step 3: When nuclear fusion begins the protostar changes to a star Step4: The star will spend 90% of its life in the main-sequence Step5: As the star gets older nuclear fusion slows and the star expands and cools forming a red giant Step 6: Once the red gi ...
2009 Assessment Schedule (90764)
... helium and becomes a main sequence star. AND Gravitational collapse explained using one or more causes stated below. Gravitational collapse can be caused by: • giant molecular clouds colliding, • passing through dense matter regions, ...
... helium and becomes a main sequence star. AND Gravitational collapse explained using one or more causes stated below. Gravitational collapse can be caused by: • giant molecular clouds colliding, • passing through dense matter regions, ...
hw4
... characteristics. For example, giant stars have thinner spectral lines generally than small stars due to density differences (giants stars have less dense atmospheres and low surface gravity). With greater densities found in smaller stars, collisions between atoms occur more frequently, distorting th ...
... characteristics. For example, giant stars have thinner spectral lines generally than small stars due to density differences (giants stars have less dense atmospheres and low surface gravity). With greater densities found in smaller stars, collisions between atoms occur more frequently, distorting th ...
Chapter 12 Stellar Evolution
... flash. The star expands into a red giant as the core continues to collapse. The envelope blows off, leaving a white dwarf to gradually cool. ...
... flash. The star expands into a red giant as the core continues to collapse. The envelope blows off, leaving a white dwarf to gradually cool. ...
doc
... (Note: No such stars actually exist - even the hottest (non-whitedwarf) stars are only about 6-7 times the Sun's temperature, and these are all somewhat larger than the Sun. This is just an exercise.) Supernovae / Stellar remnants / black holes ...
... (Note: No such stars actually exist - even the hottest (non-whitedwarf) stars are only about 6-7 times the Sun's temperature, and these are all somewhat larger than the Sun. This is just an exercise.) Supernovae / Stellar remnants / black holes ...
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.