Death of the Stars
... Heated core starts to expand immediately outwards. The outer layers are falling inwards at relativistic speeds (comparable to the speed of light) When the expanding core collides with the outer layers we have a BIG explosion. Type II Supernova. So much energy is released that all nuclear reactions ...
... Heated core starts to expand immediately outwards. The outer layers are falling inwards at relativistic speeds (comparable to the speed of light) When the expanding core collides with the outer layers we have a BIG explosion. Type II Supernova. So much energy is released that all nuclear reactions ...
Unit 11: Stellar Evolution
... The core temperature becomes so high that the nuclei themselves are broken down into individual protons and neutrons absorbing still more energy. At still-higher temperatures, electrons and protons combine to produce neutrons and neutrinos; again, an energy-absorbing reaction. Because the number of ...
... The core temperature becomes so high that the nuclei themselves are broken down into individual protons and neutrons absorbing still more energy. At still-higher temperatures, electrons and protons combine to produce neutrons and neutrinos; again, an energy-absorbing reaction. Because the number of ...
The cosmic distance scale
... Use the relation you found in one of the preparatory exercises and the min/max magnitudes of each Cepheid to calculate the observed mean magnitudes. These have to be corrected for interstellar extinction. The light traveling to us from M100 is not just passing through the vacuum of space, some of it ...
... Use the relation you found in one of the preparatory exercises and the min/max magnitudes of each Cepheid to calculate the observed mean magnitudes. These have to be corrected for interstellar extinction. The light traveling to us from M100 is not just passing through the vacuum of space, some of it ...
2014 State Test
... D7. (2 pts) What is the distance modulus associated with the distance you calculated in D6? If you didn’t get an answer to D6 or don’t want to use it, you may use 1000 parsecs for one point instead of 2. Give your answer to three significant figures. D8. (2 pts) The apparent magnitude of this RR Lyr ...
... D7. (2 pts) What is the distance modulus associated with the distance you calculated in D6? If you didn’t get an answer to D6 or don’t want to use it, you may use 1000 parsecs for one point instead of 2. Give your answer to three significant figures. D8. (2 pts) The apparent magnitude of this RR Lyr ...
Review: How does a star`s mass determine its life story?
... appears much brighter • The explosion drives accreted matter out into space ...
... appears much brighter • The explosion drives accreted matter out into space ...
30.2 PowerPoint Stellar Evolution
... the core of the star The energy from fusion balances the force of gravity and makes it a very stable stage ...
... the core of the star The energy from fusion balances the force of gravity and makes it a very stable stage ...
Main Sequence Lifetime
... • As the degenerate core grows and the shellburning rate increases, the surrounding layers of the star are heated and expand • As the star’s surface expands it becomes more luminous but also cooler • The star becomes a subgiant - luminous but red in colour • The star moves above and to the right of ...
... • As the degenerate core grows and the shellburning rate increases, the surrounding layers of the star are heated and expand • As the star’s surface expands it becomes more luminous but also cooler • The star becomes a subgiant - luminous but red in colour • The star moves above and to the right of ...
n,n - Osaka University
... In addition, the time distributions (especially late time) could exhibit interesting features such as: Schirato-Fuller anomalies from neutrino oscillations. Reddy late-time spikes from phase transition from neutron matter to quark matter (?). Cutoff from collapse to a black hole? Would all flavors t ...
... In addition, the time distributions (especially late time) could exhibit interesting features such as: Schirato-Fuller anomalies from neutrino oscillations. Reddy late-time spikes from phase transition from neutron matter to quark matter (?). Cutoff from collapse to a black hole? Would all flavors t ...
Here
... • If a white dwarf accretes matter from a close binary companion, a huge explosion on the white dwarf’s surface can be triggered. These events are called novae. ...
... • If a white dwarf accretes matter from a close binary companion, a huge explosion on the white dwarf’s surface can be triggered. These events are called novae. ...
Chapter 18 The Bizarre Stellar Graveyard What is a white dwarf
... Iron core of massive star reaches white dwarf limit and collapses into a neutron star, causing explosion ...
... Iron core of massive star reaches white dwarf limit and collapses into a neutron star, causing explosion ...
Chapter 14. Stellar Structure and Evolution
... grow. Low mass stars, on the other hand, can be so small in mass that they do not get their central temperatures high enough to start nuclear fusion of Hydrogen. The lower mass limit is about 0.07 solar masses. Lower than that limit, objects are called “brown dwarfs”. They can be seen for billions o ...
... grow. Low mass stars, on the other hand, can be so small in mass that they do not get their central temperatures high enough to start nuclear fusion of Hydrogen. The lower mass limit is about 0.07 solar masses. Lower than that limit, objects are called “brown dwarfs”. They can be seen for billions o ...
Shell supernova remnants as cosmic accelerators: I Stephen Reynolds, North Carolina State University
... “Crablike supernova remnants” after the Crab Nebula) SN ejects 1 – 10 solar masses (M⊙) at high speed into surrounding material, heating to Xray emitting temperatures (> 107 K). Expansion slows over ~105 yr. Young (“adiabatic phase”) SNRs: t < tcool ~ 10,000 yr. Observable primarily through r ...
... “Crablike supernova remnants” after the Crab Nebula) SN ejects 1 – 10 solar masses (M⊙) at high speed into surrounding material, heating to Xray emitting temperatures (> 107 K). Expansion slows over ~105 yr. Young (“adiabatic phase”) SNRs: t < tcool ~ 10,000 yr. Observable primarily through r ...
Astronomy (C) - North Carolina Science Olympiad
... 2 kinds: apparent magnitude and absolute magnitude Apparent magnitude: how bright star appears from Earth (depends on distance and type of star) Lower number means brighter star (i.e. magnitude 1 brighter than magnitude 6) Absolute magnitude: how bright star would be at 10 parsecs from Earth ...
... 2 kinds: apparent magnitude and absolute magnitude Apparent magnitude: how bright star appears from Earth (depends on distance and type of star) Lower number means brighter star (i.e. magnitude 1 brighter than magnitude 6) Absolute magnitude: how bright star would be at 10 parsecs from Earth ...
All_Stars
... the electrons will smash into the protons to form neutrons. If the mass of the core is less than ~3 Msun its collapse will be suddenly halted by neutron degeneracy pressure. The outer layers of the star, still collapsing onto the core, bounce off in a violent supernova explosion. ...
... the electrons will smash into the protons to form neutrons. If the mass of the core is less than ~3 Msun its collapse will be suddenly halted by neutron degeneracy pressure. The outer layers of the star, still collapsing onto the core, bounce off in a violent supernova explosion. ...
Cosmological Aspects of Nucleosynthesis
... The decrease of below 4/3 is a consequence of the new particles which do not immediately add their contribution to the total pressure.. At high densities: >4/3, because the electron becomes more degenerate At high temperatures: >4/3 because the particles become relativistic such that the energy ...
... The decrease of below 4/3 is a consequence of the new particles which do not immediately add their contribution to the total pressure.. At high densities: >4/3, because the electron becomes more degenerate At high temperatures: >4/3 because the particles become relativistic such that the energy ...
A Type II Supernovae Constraint on $\ nu_e $
... [2-6]. Constraints on neutrino mixing parameters have been obtained by requiring the predicted 4 He abundance under these neutrino mixings not to exceed the observed value [3-5]. Sterile neutrinos are also suggested as dark matter candidates if they have proper mixings with active neutrinos [6]. In ...
... [2-6]. Constraints on neutrino mixing parameters have been obtained by requiring the predicted 4 He abundance under these neutrino mixings not to exceed the observed value [3-5]. Sterile neutrinos are also suggested as dark matter candidates if they have proper mixings with active neutrinos [6]. In ...
HR Diagram, Star Clusters, and Stellar Evolution
... • When the core becomes pure He, a new evolutionary phase stars - the ascent to the Red Giant Branch (RGB) • Without energy generation, the core cannot support itself against gravitational collapse and so it begins to shrink; as it collapses it heats up • This heat is transferred to a thin shell ...
... • When the core becomes pure He, a new evolutionary phase stars - the ascent to the Red Giant Branch (RGB) • Without energy generation, the core cannot support itself against gravitational collapse and so it begins to shrink; as it collapses it heats up • This heat is transferred to a thin shell ...
Stellar Structure and Evolution II
... • After core helium fusion stops, He fuses into carbon in a shell around the carbon core, and H fuses to He in a shell around the helium layer • This double-shell burning stage never reaches equilibrium—fusion rate periodically spikes upward in a series of thermal pulses ...
... • After core helium fusion stops, He fuses into carbon in a shell around the carbon core, and H fuses to He in a shell around the helium layer • This double-shell burning stage never reaches equilibrium—fusion rate periodically spikes upward in a series of thermal pulses ...
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... Share and discuss your results with the rest of the class. Determine if your team’s answers are reasonable. ...
... Share and discuss your results with the rest of the class. Determine if your team’s answers are reasonable. ...
Solutions
... (a) Why is this so? (b) Why aren’t you seeing any high-luminosity massive main sequence stars? (c) Is what you are seeing representative of the population of stars in the globular cluster? Why or why not? Most of this problem could be answered by thinking about and understanding the H-R diagram of a ...
... (a) Why is this so? (b) Why aren’t you seeing any high-luminosity massive main sequence stars? (c) Is what you are seeing representative of the population of stars in the globular cluster? Why or why not? Most of this problem could be answered by thinking about and understanding the H-R diagram of a ...
Stars: Their Life and Afterlife
... fluorescence, form “planetary nebulae.” These nebulae have nothing to do with planets – they were first observed in the 1800’s and resembled Jupiter-like planets when viewed with the telescopes available then. These nebulae expand at a rate of ~10 – 30 km/s, and after 50,000 years or so have spread ...
... fluorescence, form “planetary nebulae.” These nebulae have nothing to do with planets – they were first observed in the 1800’s and resembled Jupiter-like planets when viewed with the telescopes available then. These nebulae expand at a rate of ~10 – 30 km/s, and after 50,000 years or so have spread ...
Gamma-Ray Line Emission from Radioactive Isotopes in Stars and
... Al in the Galaxy. Each prospective source has its advantages and difficulties. We discuss their nature briefly, addressing a few of the physical aspects involved. The treatment of convection, and its implications, constitute one problem area common to several source types. The convective coupling be ...
... Al in the Galaxy. Each prospective source has its advantages and difficulties. We discuss their nature briefly, addressing a few of the physical aspects involved. The treatment of convection, and its implications, constitute one problem area common to several source types. The convective coupling be ...
Booklet 5 – Stellar Processes and Evolution
... Stars with a mass of between 8 and 20 solar masses have a more complex evolution. Initially, they evolve in the same way as low mass stars, turning into red giants and undergoing a core helium burning phase. In medium mass stars, however, the burning of helium into carbon is no longer the end phase ...
... Stars with a mass of between 8 and 20 solar masses have a more complex evolution. Initially, they evolve in the same way as low mass stars, turning into red giants and undergoing a core helium burning phase. In medium mass stars, however, the burning of helium into carbon is no longer the end phase ...
Test 3 Review
... Why is the gas ionized? Remember, takes energetic UV photons to ionize H. Hot, massive stars produce huge amounts of these. Such short-lived stars spend all their lives in the stellar nursery of their birth, so emission nebulae mark sites of ongoing star formation. Many stars of lower mass are form ...
... Why is the gas ionized? Remember, takes energetic UV photons to ionize H. Hot, massive stars produce huge amounts of these. Such short-lived stars spend all their lives in the stellar nursery of their birth, so emission nebulae mark sites of ongoing star formation. Many stars of lower mass are form ...
Supernova
A supernova is a stellar explosion that briefly outshines an entire galaxy, radiating as much energy as the Sun or any ordinary star is expected to emit over its entire life span, before fading from view over several weeks or months. The extremely luminous burst of radiation expels much or all of a star's material at a velocity of up to 7007300000000000000♠30,000 km/s (10% of the speed of light), driving a shock wave into the surrounding interstellar medium. This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant. Supernovae are potentially strong galactic sources of gravitational waves. A great proportion of primary cosmic rays comes from supernovae.Supernovae are more energetic than novae. Nova means ""new"" in Latin, referring to what appears to be a very bright new star shining in the celestial sphere; the prefix ""super-"" distinguishes supernovae from ordinary novae, which are far less luminous. The word supernova was coined by Walter Baade and Fritz Zwicky in 1931. It is pronounced /ˌsuːpərnoʊvə/ with the plural supernovae /ˌsuːpərnoʊviː/ or supernovas (abbreviated SN, plural SNe after ""supernovae"").Supernovae can be triggered in one of two ways: by the sudden re-ignition of nuclear fusion in a degenerate star; or by the gravitational collapse of the core of a massive star. In the first case, a degenerate white dwarf may accumulate sufficient material from a companion, either through accretion or via a merger, to raise its core temperature, ignite carbon fusion, and trigger runaway nuclear fusion, completely disrupting the star. In the second case, the core of a massive star may undergo sudden gravitational collapse, releasing gravitational potential energy that can create a supernova explosion.The most recent directly observed supernova in the Milky Way was Kepler's Star of 1604 (SN 1604); remnants of two more recent supernovae have been found retrospectively. Observations in other galaxies indicate that supernovae should occur on average about three times every century in the Milky Way, and that any galactic supernova would almost certainly be observable in modern astronomical equipment. Supernovae play a significant role in enriching the interstellar medium with higher mass elements. Furthermore, the expanding shock waves from supernova explosions can trigger the formation of new stars.