Life Cycle of a Star
... into space, fading into black lumps of carbon. This is when the star becomes a black dwarf (stage 14) . ...
... into space, fading into black lumps of carbon. This is when the star becomes a black dwarf (stage 14) . ...
Stellar Evolution (Formation)
... Sun has enough H in its core to produce energy for about 1010 yrs. (It is about halfway through its life now.) When the core’s H is exhausted, there will be no more nuclear energy to heat the gas. Gravity will win over gas pressure and the core will collapse. Gravitational potential energy of th ...
... Sun has enough H in its core to produce energy for about 1010 yrs. (It is about halfway through its life now.) When the core’s H is exhausted, there will be no more nuclear energy to heat the gas. Gravity will win over gas pressure and the core will collapse. Gravitational potential energy of th ...
Lecture Notes – Stars
... the escape velocity equals the speed of light RSch = 2GM/c2 (for Sun RSch = 3 km). Also called the event horizon - nothing can escape. ...
... the escape velocity equals the speed of light RSch = 2GM/c2 (for Sun RSch = 3 km). Also called the event horizon - nothing can escape. ...
Ia 超新星的
... The light curve peak lasts for several days, and displays exponential decline at late time Most of SNe Ia show relatively similar spectra and light curves shapes, but definite departures from the canonical events have also been observed. SNe Ia explosion have been detected in galaxies of all Hubble ...
... The light curve peak lasts for several days, and displays exponential decline at late time Most of SNe Ia show relatively similar spectra and light curves shapes, but definite departures from the canonical events have also been observed. SNe Ia explosion have been detected in galaxies of all Hubble ...
Stages - A Summary - University of Dayton
... the asymptotic giant branch into the red super- giant region; the star could continue the nuclear reaction sequence and fuse the carbon atoms, but its gravity is not high enough to generate the temperatures needed (about 600 million K) for this to happen, so it has essentially reached the end of its ...
... the asymptotic giant branch into the red super- giant region; the star could continue the nuclear reaction sequence and fuse the carbon atoms, but its gravity is not high enough to generate the temperatures needed (about 600 million K) for this to happen, so it has essentially reached the end of its ...
(a) Because the core of heavy-mass star never reaches high enough
... 15. Which one of the following is the right set of descriptions for the “Solar Thermostat”? (a) When core temperature increases, pressure increases. Higher pressure expands the system which then cools the core. (b) When core temperature decreases, pressure increases. Higher pressure expands the sys ...
... 15. Which one of the following is the right set of descriptions for the “Solar Thermostat”? (a) When core temperature increases, pressure increases. Higher pressure expands the system which then cools the core. (b) When core temperature decreases, pressure increases. Higher pressure expands the sys ...
Star formation and Evolution
... hydrogen into helium. Because stars shine by those nuclear reactions, they have a finite life span. The theory of stellar evolution describes how stars form and change during that life span. Stars are formed when part of a interstellar gas cloud contracts under its own gravitational force; as it col ...
... hydrogen into helium. Because stars shine by those nuclear reactions, they have a finite life span. The theory of stellar evolution describes how stars form and change during that life span. Stars are formed when part of a interstellar gas cloud contracts under its own gravitational force; as it col ...
31 October: Supernovae and Neutron Stars
... • Radius versus mass relation for neutron star • Notice size of neutron star • Masses extend above Chandrasekhar limit ...
... • Radius versus mass relation for neutron star • Notice size of neutron star • Masses extend above Chandrasekhar limit ...
112501. r-process beam neutron
... nucleosynthesis. Weak rates in this mass region are not well understood: GT strength distributions first-forbidden contribution Fröhlich et al., PRL 96 (2006) ...
... nucleosynthesis. Weak rates in this mass region are not well understood: GT strength distributions first-forbidden contribution Fröhlich et al., PRL 96 (2006) ...
Lecture 10
... One Iron photodisintegration takes place, core collapses on time scale of 10’s of ms. At “Low” masses, Neutron star is formed, and shock appears. As long as there is large fluxes of infalling material, shock cannot “leave” the core. Once shock does propagates outwards (perhaps using n heating) it: ...
... One Iron photodisintegration takes place, core collapses on time scale of 10’s of ms. At “Low” masses, Neutron star is formed, and shock appears. As long as there is large fluxes of infalling material, shock cannot “leave” the core. Once shock does propagates outwards (perhaps using n heating) it: ...
The Stellar Graveyard
... main sequence star. All of the hydrogen and helium that used to be in the star has been lost in the Post Red Giant phase of stellar evolution. White dwarfs usually have masses between 0.5 and 1 solar mass and have collapsed down to the size of the Earth. Thus their densities are extremely large, on ...
... main sequence star. All of the hydrogen and helium that used to be in the star has been lost in the Post Red Giant phase of stellar evolution. White dwarfs usually have masses between 0.5 and 1 solar mass and have collapsed down to the size of the Earth. Thus their densities are extremely large, on ...
Lecture15
... and white dwarfs are all examples of stars that have evolved off the main sequence. • The luminosity and effective temperature are the main observable predictions of stellar models. ...
... and white dwarfs are all examples of stars that have evolved off the main sequence. • The luminosity and effective temperature are the main observable predictions of stellar models. ...
Studying the Metallicities of Dwarf Galaxies Myles McKay (SCSU)
... NO DEFINITION! Milky Way Galaxy ...
... NO DEFINITION! Milky Way Galaxy ...
The correct answers are written in bold, italic and underlined. The
... Cosmic rays are made up primarily of atomic nuclei that travel through space after being accelerated to very high speeds and energies, often by processes associated with supernovae. 5. What is believed to be the origin of most of the cosmic rays arriving at the Earth from outside the solar system? • ...
... Cosmic rays are made up primarily of atomic nuclei that travel through space after being accelerated to very high speeds and energies, often by processes associated with supernovae. 5. What is believed to be the origin of most of the cosmic rays arriving at the Earth from outside the solar system? • ...
To understand the deaths of stars and how it
... Electrons to the rescue! • It is humbling that to save this large star it takes something as small as an electron to save it. • At some point the density of the core gets to a MILLION times the density of water! • At this point the electrons are crammed so closely that they repel each other. • Whil ...
... Electrons to the rescue! • It is humbling that to save this large star it takes something as small as an electron to save it. • At some point the density of the core gets to a MILLION times the density of water! • At this point the electrons are crammed so closely that they repel each other. • Whil ...
Chapter 6: Stellar Evolution (part 2)
... which are lacking in Type Ic SNe. Similar to SNe II, they are found in star-forming regions, and their late-time spectra are also similar to Type II. A subclass of very bright Type Ic supernovae, known as hypernovae, may be associated with gamma-ray bursts. ...
... which are lacking in Type Ic SNe. Similar to SNe II, they are found in star-forming regions, and their late-time spectra are also similar to Type II. A subclass of very bright Type Ic supernovae, known as hypernovae, may be associated with gamma-ray bursts. ...
Chapter 12
... The gravitational force depends on the product of the masses and is inversely proportional to the distance squared. The masses of the Sun (or black hole) and the Earth are the same and the distance remain the same!!! ...
... The gravitational force depends on the product of the masses and is inversely proportional to the distance squared. The masses of the Sun (or black hole) and the Earth are the same and the distance remain the same!!! ...
Astronomy_Stellar_Evolution_and_Type_II_Supernovae_Exam
... 6) Spectral class K or M, with luminosities that can exceed 500,000 solar units. 7) Two companions consisting of a Donor and an Accretor. As material moves between the two it is heated until energy with a frequency of approximately 3×1016 Hz to 3×1019 Hz is produced. 8) Massive stars with an excepti ...
... 6) Spectral class K or M, with luminosities that can exceed 500,000 solar units. 7) Two companions consisting of a Donor and an Accretor. As material moves between the two it is heated until energy with a frequency of approximately 3×1016 Hz to 3×1019 Hz is produced. 8) Massive stars with an excepti ...
Chapter 15 (Star Lives)
... D. are at different stages of their lives. 2. In making a model of a star, an astronomer does NOT have to know or assume: A. that the energy given off is produced in the interior. B. the mass of the star. C. the chemical composition of the star. D. the distance to that star. 3. For a star like our s ...
... D. are at different stages of their lives. 2. In making a model of a star, an astronomer does NOT have to know or assume: A. that the energy given off is produced in the interior. B. the mass of the star. C. the chemical composition of the star. D. the distance to that star. 3. For a star like our s ...
A Summary of Stages
... the asymptotic giant branch into the red super- giant region; the star could continue the nuclear reaction sequence and fuse the carbon atoms, but its gravity is not high enough to generate the temperatures needed (about 600 million K) for this to happen, so it has essentially reached the end of its ...
... the asymptotic giant branch into the red super- giant region; the star could continue the nuclear reaction sequence and fuse the carbon atoms, but its gravity is not high enough to generate the temperatures needed (about 600 million K) for this to happen, so it has essentially reached the end of its ...
PHYS 2410 General Astronomy Homework 7
... The energy emitted from the surface of a main sequence star is _____the energy generated in the core. a. ...
... The energy emitted from the surface of a main sequence star is _____the energy generated in the core. a. ...
The Stellar Cycle
... electrons apart is called electron degeneracy pressure – this is what balances the weight. • Only if more energy drives the electrons into higher energy states, can the density increase. • Adding mass can drive electrons to higher energies so star shrinks. • At 1.4 solar masses—the Chandrasekhar Lim ...
... electrons apart is called electron degeneracy pressure – this is what balances the weight. • Only if more energy drives the electrons into higher energy states, can the density increase. • Adding mass can drive electrons to higher energies so star shrinks. • At 1.4 solar masses—the Chandrasekhar Lim ...
Galaxies - Indiana University Astronomy
... exploding white dwarfs, and Type II supernovae, which are explosions of massive stars that run out of nuclear fuel. The light curves of supernovae of Type Ia and Type II are compared in the figure below. Type Ia supernova rise to maximum and then fall steadily in brightness, fading in just a few wee ...
... exploding white dwarfs, and Type II supernovae, which are explosions of massive stars that run out of nuclear fuel. The light curves of supernovae of Type Ia and Type II are compared in the figure below. Type Ia supernova rise to maximum and then fall steadily in brightness, fading in just a few wee ...
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.