Stellar Evolution – Life of a Star
... • White Dwarfs are also burning, but these stars burn heavier elements (e.g. C). Each burning creates and burns a heavier element (e.g, Ne, O, Si, S and Fe). The burning raises the core temperature and each elemental burning period is shorter than the previous. Fusion cannot continue after Fe, inter ...
... • White Dwarfs are also burning, but these stars burn heavier elements (e.g. C). Each burning creates and burns a heavier element (e.g, Ne, O, Si, S and Fe). The burning raises the core temperature and each elemental burning period is shorter than the previous. Fusion cannot continue after Fe, inter ...
Determination of the astrophysical S factor of the 8B(p,γ)
... in Table 1. These values exhibit fluctuations of about ±19% around the average value. In the calculation of S18 presented below, the average over all the plotted values of (C1,3/2 )2 + (C1,1/2)2 has been used. As stressed in Ref. [25] the determination of optical potentials, particularly in the entr ...
... in Table 1. These values exhibit fluctuations of about ±19% around the average value. In the calculation of S18 presented below, the average over all the plotted values of (C1,3/2 )2 + (C1,1/2)2 has been used. As stressed in Ref. [25] the determination of optical potentials, particularly in the entr ...
Part 2 - Stellar Evolution
... For a degenerate gas, the ignition of helium burning will heat the gas, but do not cause expand The increased temperature makes the reaction go faster, which further heats the gas, which makes the reaction goes faster. This cycle of explosive nuclear reaction continues until temperature is high enou ...
... For a degenerate gas, the ignition of helium burning will heat the gas, but do not cause expand The increased temperature makes the reaction go faster, which further heats the gas, which makes the reaction goes faster. This cycle of explosive nuclear reaction continues until temperature is high enou ...
Astrophysics 12 - Stellar Evolution
... For stars with mass similar to the of the Sun, the carbon-oxygen core isn’t hot enough for fusion. The core continues to contract until electrons exert enough pressure to stop it collapsing further. ...
... For stars with mass similar to the of the Sun, the carbon-oxygen core isn’t hot enough for fusion. The core continues to contract until electrons exert enough pressure to stop it collapsing further. ...
AST1100 Lecture Notes
... the collapse is suddenly stopped, the core bounces back and an energetic shock wave is generated. This shock wave travels outwards from the core but is blocked by the massive and dense ’iron cap’, the outer core, which is in free fall towards the inner core. The energy of the shock wave heats the ou ...
... the collapse is suddenly stopped, the core bounces back and an energetic shock wave is generated. This shock wave travels outwards from the core but is blocked by the massive and dense ’iron cap’, the outer core, which is in free fall towards the inner core. The energy of the shock wave heats the ou ...
Objectives
... • Less massive stars burn cooler and therefore can last longer • Our Sun will fuse hydrogen for about 10 billion years • Once a star’s Hydrogen supply runs out, fusion stops and the core begins to contract • At this time, the outer layers of hydrogen fuse at an incredible rate and the star expands t ...
... • Less massive stars burn cooler and therefore can last longer • Our Sun will fuse hydrogen for about 10 billion years • Once a star’s Hydrogen supply runs out, fusion stops and the core begins to contract • At this time, the outer layers of hydrogen fuse at an incredible rate and the star expands t ...
Stars & Galaxies
... © 2006, TESCCC The content of this multimedia presentation is intended for use by TESCCC subscribers for intra-district professional development ONLY; and may not be used for other purposes, in whole or part, without the expressed written permission of their ESC-TESCCC coordinator for the region han ...
... © 2006, TESCCC The content of this multimedia presentation is intended for use by TESCCC subscribers for intra-district professional development ONLY; and may not be used for other purposes, in whole or part, without the expressed written permission of their ESC-TESCCC coordinator for the region han ...
The s-process in low metallicity stars - GSI
... sigma(A)Ns(A) versus atomic mass number A, but interrupted by steep decreases in correspondence of magic neutron numbers N = 50, 82 or 126, where the neutron capture cross sections are very small and the resulting s-process abundances are large. This happens at the first s-peak at Sr, Y, Zr, at the ...
... sigma(A)Ns(A) versus atomic mass number A, but interrupted by steep decreases in correspondence of magic neutron numbers N = 50, 82 or 126, where the neutron capture cross sections are very small and the resulting s-process abundances are large. This happens at the first s-peak at Sr, Y, Zr, at the ...
Variable Stars: Pulsation, Evolution and applications to Cosmology
... Recall equations of stellar structure. Nuclear energy generation rate ε(ρ,T) slowly changes the composition decreasing the amount of Hydrogen and increasing the amount of Helium on a nuclear time scale – the characteristic time for stellar properties to change as a result of nuclear burning: tnuc ~ ...
... Recall equations of stellar structure. Nuclear energy generation rate ε(ρ,T) slowly changes the composition decreasing the amount of Hydrogen and increasing the amount of Helium on a nuclear time scale – the characteristic time for stellar properties to change as a result of nuclear burning: tnuc ~ ...
White dwarfs & supernovae — Oct 19 white dwarfs?
... Sirius A, a main-sequence star Sirius B, an earth-sized white dwarf ...
... Sirius A, a main-sequence star Sirius B, an earth-sized white dwarf ...
Extra revision sheet quarter 2 Physical science Grade 9
... total distance covered by the time of travel gives ____________________. 4. When an object is seen moving in relation to a stationary object, the stationary object is called ____________________. 5. Acceleration is the rate at which ____________________ changes. 6. When a car skids on a wet road, it ...
... total distance covered by the time of travel gives ____________________. 4. When an object is seen moving in relation to a stationary object, the stationary object is called ____________________. 5. Acceleration is the rate at which ____________________ changes. 6. When a car skids on a wet road, it ...
Stellar Masses and the Main Sequence
... In general, the opacity of a star is proportional to its metal abundance (due to bound-free transitions and electrons supplied to H-.) The lower the metal abundance, the smaller the opacity, the less energy is trapped in the star doing work, the smaller the star, and therefore the hotter the star. T ...
... In general, the opacity of a star is proportional to its metal abundance (due to bound-free transitions and electrons supplied to H-.) The lower the metal abundance, the smaller the opacity, the less energy is trapped in the star doing work, the smaller the star, and therefore the hotter the star. T ...
Assignment on Principles of Visualization
... There are mainly four phases in the life cycle of a star. Brief description of those phases is given below: Contraction Phase: Outer space which is filled very thin clouds of hydrogen, helium and dust like interstellar particles which are the raw materials of future stars. Clusters of interstellar p ...
... There are mainly four phases in the life cycle of a star. Brief description of those phases is given below: Contraction Phase: Outer space which is filled very thin clouds of hydrogen, helium and dust like interstellar particles which are the raw materials of future stars. Clusters of interstellar p ...
Neutron Stars and Pulsars
... • Isolated black holes are impossible for us to see from Earth, because they’re small and emit no light. • A black hole is more likely to be recognized if it has a visible companion that isn’t a black hole. • A black hole with a visible companion will be a strong source of xrays. The x-ray emission ...
... • Isolated black holes are impossible for us to see from Earth, because they’re small and emit no light. • A black hole is more likely to be recognized if it has a visible companion that isn’t a black hole. • A black hole with a visible companion will be a strong source of xrays. The x-ray emission ...
Worksheet 1
... A. The time period for about A.D. 1600 to 1740 during which the Sun was relatively inactive B. The binding of two light nuclei to form a heavier nucleus with some nuclear mass converted to energy C. The region immediately below the Sun’s visible surface in which its heat is carried by convection D. ...
... A. The time period for about A.D. 1600 to 1740 during which the Sun was relatively inactive B. The binding of two light nuclei to form a heavier nucleus with some nuclear mass converted to energy C. The region immediately below the Sun’s visible surface in which its heat is carried by convection D. ...
Stellar Explosions
... Carbon can then fuse, either with itself or with alpha particles, to form more nuclei ...
... Carbon can then fuse, either with itself or with alpha particles, to form more nuclei ...
Star - Astrophysics
... These stellar explosions are extremely luminous, with absolute magnitudes MB around -16 to -20, the same as a whole small to moderate sized galaxy. Most are seen in external galaxies (e.g. SN1987A in the Large Magellanic Cloud). We expect around 1 every 30 years in our Galaxy, though none has been s ...
... These stellar explosions are extremely luminous, with absolute magnitudes MB around -16 to -20, the same as a whole small to moderate sized galaxy. Most are seen in external galaxies (e.g. SN1987A in the Large Magellanic Cloud). We expect around 1 every 30 years in our Galaxy, though none has been s ...
Stellar evolution
... - First occurs in a runaway process: "the helium flash". Energy from fusion goes into re-expanding and cooling the core. This slows fusion, so star gets dimmer again. - Then stable He -> C burning. Still have H -> He shell burning surrounding it. ...
... - First occurs in a runaway process: "the helium flash". Energy from fusion goes into re-expanding and cooling the core. This slows fusion, so star gets dimmer again. - Then stable He -> C burning. Still have H -> He shell burning surrounding it. ...
P-nuclei
p-Nuclei (p stands for proton-rich) are certain proton-rich, naturally occurring isotopes of some elements between selenium and mercury which cannot be produced in either s- or r-process.