Stars - Red, Blue, Old, New pt.2
... very important factor in stellar evolution • The more massive a star is, the faster it will evolve (due to faster thermonuclear reaction rates in core) • Main sequence lifetime of sun is 12 billion years; 50xsun only about 50,000 years ...
... very important factor in stellar evolution • The more massive a star is, the faster it will evolve (due to faster thermonuclear reaction rates in core) • Main sequence lifetime of sun is 12 billion years; 50xsun only about 50,000 years ...
The slow-neutron capture process at low metallicity
... We present models for the slow neutron capture (s-process) in AGB stars of metallicity, Z = 0.0001 [Fe/H] = -2.3 Mass range from 0.9Msun to 6Msun, where we have explored model uncertainties by using two independent stellar evolution codes We encountered 4 regimes of neutron-capture nucleosynthesis M ...
... We present models for the slow neutron capture (s-process) in AGB stars of metallicity, Z = 0.0001 [Fe/H] = -2.3 Mass range from 0.9Msun to 6Msun, where we have explored model uncertainties by using two independent stellar evolution codes We encountered 4 regimes of neutron-capture nucleosynthesis M ...
doc
... expand will cool the core, reduce the pressure, and cause the star to contract, returning to its original state. This is what we mean by “stable.” Depletion of H in core [see Fig. 20.2]. Look at the nuclear burning “eating away” at the core H and leaving He behind. Starting in center (hottest), and ...
... expand will cool the core, reduce the pressure, and cause the star to contract, returning to its original state. This is what we mean by “stable.” Depletion of H in core [see Fig. 20.2]. Look at the nuclear burning “eating away” at the core H and leaving He behind. Starting in center (hottest), and ...
Downloadable Full Text
... The UFD Reticulum II (Ret II) was recently discovered with Dark Energy Survey data12,13 and confirmed to be one of the most metal-poor galaxies known14. On 1-4 Oct 2015, we obtained high-resolution spectra of the nine brightest member stars in Ret II (see Table 1, Extended Data Figure 1). The abunda ...
... The UFD Reticulum II (Ret II) was recently discovered with Dark Energy Survey data12,13 and confirmed to be one of the most metal-poor galaxies known14. On 1-4 Oct 2015, we obtained high-resolution spectra of the nine brightest member stars in Ret II (see Table 1, Extended Data Figure 1). The abunda ...
Stellar Evolution (Formation)
... Thus MJ ~ 2 Msun The characteristic mass of these dense cores is ~ 10 Msun so they are unstable to gravitational collapse - consistent with them being sites of star formation. ...
... Thus MJ ~ 2 Msun The characteristic mass of these dense cores is ~ 10 Msun so they are unstable to gravitational collapse - consistent with them being sites of star formation. ...
Supercomputer simulation provides missing link between turbulence, hypernovae and gamma-ray bursts
... outside the visible or ultraviolet bands – that they were not observed until 1967 by satellites looking for evidence of nuclear bomb tests. Most are billions of light years away in distant galaxies, so the fact we can see them at all means they are among the brightest events in the universe. Observa ...
... outside the visible or ultraviolet bands – that they were not observed until 1967 by satellites looking for evidence of nuclear bomb tests. Most are billions of light years away in distant galaxies, so the fact we can see them at all means they are among the brightest events in the universe. Observa ...
Gravitationally redshifted absorption lines in the x
... Obs. Results of GS 1826-24 XMM-Newton RGS average ...
... Obs. Results of GS 1826-24 XMM-Newton RGS average ...
HR Diagram Practice Page
... 1. Which star is brighter? Aldeberan or Betelgeuse 2. Which star is cooler? Rigel or Mira 3. Which star is larger in size? Polaris or Alpha Centauri B 4. Which star has a higher temperature? Tau Ceti or Procyon B 5. Which star is hotter? Regulus or Deneb 6. Which star is smaller in size? Sun or Anta ...
... 1. Which star is brighter? Aldeberan or Betelgeuse 2. Which star is cooler? Rigel or Mira 3. Which star is larger in size? Polaris or Alpha Centauri B 4. Which star has a higher temperature? Tau Ceti or Procyon B 5. Which star is hotter? Regulus or Deneb 6. Which star is smaller in size? Sun or Anta ...
Ay 1 – Final Exam
... A. It absorbed a photon of energy greater than or equal to the energy difference between ground and the excited state B. It tunneled to a higher energy state C. Another atom of sufficient energy collided with it D. Either A or C E. EIther A, B or C 14. Which one of the following has never been used ...
... A. It absorbed a photon of energy greater than or equal to the energy difference between ground and the excited state B. It tunneled to a higher energy state C. Another atom of sufficient energy collided with it D. Either A or C E. EIther A, B or C 14. Which one of the following has never been used ...
Solutions to Homework #4, AST 203, Spring 2012
... no mass. It has recently been discovered (using the same Kamiokande experiment described above!) that they in fact do have a very small mass; each neutrino has a mass of roughly 6 × 10−8 that of an electron. This discovery (together with the detection of neutrinos from the supernova) was recognized ...
... no mass. It has recently been discovered (using the same Kamiokande experiment described above!) that they in fact do have a very small mass; each neutrino has a mass of roughly 6 × 10−8 that of an electron. This discovery (together with the detection of neutrinos from the supernova) was recognized ...
AS2001 - University of St Andrews
... (Mg,O,Si,Ca,Ti,Al) formed early, reaching 2-3 x Fe abundance in metal-poor stars ...
... (Mg,O,Si,Ca,Ti,Al) formed early, reaching 2-3 x Fe abundance in metal-poor stars ...
Fifth - Department of Physics and Astronomy
... see that there is no radius for which the star will be in equilibrium: the star just collapses. • From the same equation we can derive the mass of such star. For masses larger than the Chandrasekhar mass limit, the star collapses. ...
... see that there is no radius for which the star will be in equilibrium: the star just collapses. • From the same equation we can derive the mass of such star. For masses larger than the Chandrasekhar mass limit, the star collapses. ...
The Luminosity
... -10 billiion yrs: the Sun runs out of hydrogen fuel in its core. - Core is pure helium, shrinks. - Hydrogen farther out in the star gets hot enough to fuse “hydrogen shell burning” - Overall luminosity of star goes up and becomes a red giant. - 300million yrs later: Core gets hot enough to fuse heli ...
... -10 billiion yrs: the Sun runs out of hydrogen fuel in its core. - Core is pure helium, shrinks. - Hydrogen farther out in the star gets hot enough to fuse “hydrogen shell burning” - Overall luminosity of star goes up and becomes a red giant. - 300million yrs later: Core gets hot enough to fuse heli ...
Supernovae and cosmology
... Metal core too heavy for electron degeneracy Weight more than Chandrasekar limit Core collapses Pressure increases on gas surrounding core Potential energy is released as heat ...
... Metal core too heavy for electron degeneracy Weight more than Chandrasekar limit Core collapses Pressure increases on gas surrounding core Potential energy is released as heat ...
Free Referat Word Dimensiune: 63.5KB
... When the helium is exhausted in the core of a star like the sun, the C-O core will begin to contract again. Central temperatures will never reach high enough values for Carbon or Oxygen burning, but the Helium and Hydrogen burning shells will conyinue burning for a while. Throughout the star's lifet ...
... When the helium is exhausted in the core of a star like the sun, the C-O core will begin to contract again. Central temperatures will never reach high enough values for Carbon or Oxygen burning, but the Helium and Hydrogen burning shells will conyinue burning for a while. Throughout the star's lifet ...
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.