STARS IN HYDROSTATIC EQUILIBRIUM Gravitational energy and
... to find a relations between thermal and gravitational energy of a star. As we shall be changing variables many times we shall adopt a convention of using ”c” as a symbol of a stellar center and the lower limit of an integral, and ”s” as a symbol of a stellar surface and the upper limit of an integra ...
... to find a relations between thermal and gravitational energy of a star. As we shall be changing variables many times we shall adopt a convention of using ”c” as a symbol of a stellar center and the lower limit of an integral, and ”s” as a symbol of a stellar surface and the upper limit of an integra ...
–1– 1. The Salpeter Initial Mass Function The initial mass function is
... the seminal work of Miller & Scalo (1979). This goes in two steps. First, a present day mass function, PDMF or φ(logM) for main sequence stars is found. This is the number of stars per mass per unit area in the galaxy; it is integrated over the ”vertical” dimension of the disk. The PDMF is given by ...
... the seminal work of Miller & Scalo (1979). This goes in two steps. First, a present day mass function, PDMF or φ(logM) for main sequence stars is found. This is the number of stars per mass per unit area in the galaxy; it is integrated over the ”vertical” dimension of the disk. The PDMF is given by ...
Life Cycle of a Star
... and begins a nuclear reaction that causes hydrogen to form helium, releasing energy in the form of heat and light. A low mass star will stay in this MAIN SEQUENCE phase for a long time, until it begins to use up all of it’s hydrogen. ...
... and begins a nuclear reaction that causes hydrogen to form helium, releasing energy in the form of heat and light. A low mass star will stay in this MAIN SEQUENCE phase for a long time, until it begins to use up all of it’s hydrogen. ...
PRESENTATION: Evolution of the elements through the lifecycles of
... -Once the Iron in the core of a star has reached a relative density of 100,000 Kg per cm3, the star has reached a point of critical mass and will explode into a supernova. (Hold up my 100 metric ton Bouillon cube). -A star will not fuse iron because it has the most stable nucleus of all the elements ...
... -Once the Iron in the core of a star has reached a relative density of 100,000 Kg per cm3, the star has reached a point of critical mass and will explode into a supernova. (Hold up my 100 metric ton Bouillon cube). -A star will not fuse iron because it has the most stable nucleus of all the elements ...
Luminosity
... • What is the significance of the main sequence? — Normal stars that fuse H to He in their cores fall on the main sequence of an H-R diagram. — A star’s mass determines its position along the main sequence (high mass: luminous and blue; low mass: faint and red). ...
... • What is the significance of the main sequence? — Normal stars that fuse H to He in their cores fall on the main sequence of an H-R diagram. — A star’s mass determines its position along the main sequence (high mass: luminous and blue; low mass: faint and red). ...
Project 4: The HR diagram. Open clusters
... temperature, high luminosity stars to low temperature, low luminosity stars. These are the main sequence stars. Our Sun is one of them. There are a few stars that are not in this diagonal strip. There are some low temperature, high luminosity stars ‐ these are called giants and super ...
... temperature, high luminosity stars to low temperature, low luminosity stars. These are the main sequence stars. Our Sun is one of them. There are a few stars that are not in this diagonal strip. There are some low temperature, high luminosity stars ‐ these are called giants and super ...
–1– Lecture 21 Review: calculation of mean atomic weight of an
... too cold for liquid water to exist. The most common explanation is that the greenhouse effect kept the surface warmer (the Earth’s atmosphere was rich in CO2 early on). As the same ages, it will get warmer. In about 1 billion years, predictions show the Oceans evaporating in a runaway greenhouse eff ...
... too cold for liquid water to exist. The most common explanation is that the greenhouse effect kept the surface warmer (the Earth’s atmosphere was rich in CO2 early on). As the same ages, it will get warmer. In about 1 billion years, predictions show the Oceans evaporating in a runaway greenhouse eff ...
Week 12, Lecture 2 – Nuclear Synthesis
... wide range of objects including planets, stars, galaxies, clusters of galaxies, etc. through gravita
... wide range of objects including planets, stars, galaxies, clusters of galaxies, etc. through gravita
June - San Bernardino Valley Amateur Astronomers
... discovered that one of the most luminous stars known is actually a lone wolf. This discovery might change how astronomers think stars are born and end up on their own. The gigantic star, called VFTS 682, is approximately 150 times the mass of the sun. It lies in the Large Magellanic Cloud, a small g ...
... discovered that one of the most luminous stars known is actually a lone wolf. This discovery might change how astronomers think stars are born and end up on their own. The gigantic star, called VFTS 682, is approximately 150 times the mass of the sun. It lies in the Large Magellanic Cloud, a small g ...
Stellar Evolution: The Live and Death of a Star
... • As hydrogen is consumed, balance between gravity and pressure begins to shift, both internal structure and outward appearance begin to change, and the star leaves the main sequence. • The end of a star’s life depends critically on its mass. Low mass stars die gently High mass stars die catastrop ...
... • As hydrogen is consumed, balance between gravity and pressure begins to shift, both internal structure and outward appearance begin to change, and the star leaves the main sequence. • The end of a star’s life depends critically on its mass. Low mass stars die gently High mass stars die catastrop ...
Lecture 9
... We now need to assume something about the source of pressure in the star. We require an equation of state to relate the pressure to macroscopic properties of the gas (i.e. temperature and density) ...
... We now need to assume something about the source of pressure in the star. We require an equation of state to relate the pressure to macroscopic properties of the gas (i.e. temperature and density) ...
1. What is the HR diagram? 1a. The HR diagram is a plot of a star`s
... On the horizontal branch, how is the star powered? What burns where? Helium burning in the core. No real shell burning at this stage. On the asymptotic giant branch (AGB), can you ever get a helium burning shell outside a hydrogen burning shell? If not, why not? No because Helium burning requires a ...
... On the horizontal branch, how is the star powered? What burns where? Helium burning in the core. No real shell burning at this stage. On the asymptotic giant branch (AGB), can you ever get a helium burning shell outside a hydrogen burning shell? If not, why not? No because Helium burning requires a ...
Wednesday, April 23 - Otterbein University
... Super-Massive Stars end up as Black Holes • If the mass of the star is sufficiently large (M > 25 MSun), even the neutron pressure cannot halt the collapse – in fact, no known force can stop it! • The star collapses to a very small size, with ultrahigh density • Nearby gravity becomes so strong tha ...
... Super-Massive Stars end up as Black Holes • If the mass of the star is sufficiently large (M > 25 MSun), even the neutron pressure cannot halt the collapse – in fact, no known force can stop it! • The star collapses to a very small size, with ultrahigh density • Nearby gravity becomes so strong tha ...
HR Diagram Explorer
... indicated by a red x. This active location can be dragged around the diagram. The options panel allows you control the variables plotted on the x-axis: (temperature, B-V, or spectral type) and those plotted on the y-axis (luminosity or absolute magnitude). One can also show the main sequence, lumino ...
... indicated by a red x. This active location can be dragged around the diagram. The options panel allows you control the variables plotted on the x-axis: (temperature, B-V, or spectral type) and those plotted on the y-axis (luminosity or absolute magnitude). One can also show the main sequence, lumino ...
Stellar Evolution
... Binding energy is a result of the strong nuclear force. It has a very short range. It is the strongest of the 4 known ...
... Binding energy is a result of the strong nuclear force. It has a very short range. It is the strongest of the 4 known ...
A Tale of Star and Planet Formation
... because binary stars are typically very close together in projection and because atmospheric distortions blur our observations. Keck can observe these stars because of a technology called Adaptive Optics. AO corrects the atmospheric distortions that normally limit the resolution of telescopes. ...
... because binary stars are typically very close together in projection and because atmospheric distortions blur our observations. Keck can observe these stars because of a technology called Adaptive Optics. AO corrects the atmospheric distortions that normally limit the resolution of telescopes. ...
Ch_16-18_Example_Exam
... ____ 17. In the CNO cycle, carbon is used a catalyst for the fusion of hydrogen to helium. This means that: a. three helium nuclei fuse to form carbon b. carbon facilitates the reaction but is not consumed in it c. carbon boosts the energy from the reaction, which is why massive stars are luminous d ...
... ____ 17. In the CNO cycle, carbon is used a catalyst for the fusion of hydrogen to helium. This means that: a. three helium nuclei fuse to form carbon b. carbon facilitates the reaction but is not consumed in it c. carbon boosts the energy from the reaction, which is why massive stars are luminous d ...
S E D
... To explain the stellar structure we need to assume thermodynamical equilibrium. It results in that we do not need to think of reactions in the gas. This assumption is okay, as long as there is full ionization, and therefore we can assume this almost in the whole star except the surface. Another assu ...
... To explain the stellar structure we need to assume thermodynamical equilibrium. It results in that we do not need to think of reactions in the gas. This assumption is okay, as long as there is full ionization, and therefore we can assume this almost in the whole star except the surface. Another assu ...
Goal: To understand how stars form.
... • NOTE: kinetic energy is the energy of motion. If something stops moving, that energy has to go somewhere. In collisions like this it goes into heat! • At some point the central object starts to radiate this newly acquired heat and becomes a protostar. ...
... • NOTE: kinetic energy is the energy of motion. If something stops moving, that energy has to go somewhere. In collisions like this it goes into heat! • At some point the central object starts to radiate this newly acquired heat and becomes a protostar. ...
Lecture Notes – Stars
... On the main sequence, H-burning is by the CNO cycle. Post-main-sequence evolution is broadly similar to the 1-M star, with the following important differences: (1) Since the core temperature is much higher, burning of further elements can occur, depending on mass of star. The helium flash does not ...
... On the main sequence, H-burning is by the CNO cycle. Post-main-sequence evolution is broadly similar to the 1-M star, with the following important differences: (1) Since the core temperature is much higher, burning of further elements can occur, depending on mass of star. The helium flash does not ...
Star Formation Triggers More Star Formation
... – Never gets hot enough for stable hydrogen to helium fusion. – Star is “stillborn” – Starts with a surface temperature of about 3,500 K, then cools down. – Called a brown dwarf ...
... – Never gets hot enough for stable hydrogen to helium fusion. – Star is “stillborn” – Starts with a surface temperature of about 3,500 K, then cools down. – Called a brown dwarf ...
Components of the Milky Way
... Conclude: massive stars are short lived, but for most stars hydrogen burning lifetime is long compared to formation time† scale. ASTR 3730: Fall 2003 ...
... Conclude: massive stars are short lived, but for most stars hydrogen burning lifetime is long compared to formation time† scale. ASTR 3730: Fall 2003 ...
H-R Diagram
... To identify the characteristics of a star from data in the diagram To classify a star by its position in the diagram To compare the life cycle stages of stars based on their positions in the diagram Background The Hertzsprung-Russell diagram, or H-R diagram, is a graph in which a star's temperature ...
... To identify the characteristics of a star from data in the diagram To classify a star by its position in the diagram To compare the life cycle stages of stars based on their positions in the diagram Background The Hertzsprung-Russell diagram, or H-R diagram, is a graph in which a star's temperature ...
Slide 1
... Once thermonuclear fusion in the center of a star is ignited, the star will heat up and become more luminous. Thus, which way will it “move” in the Hertzsprung-Russell (HR) diagram? ...
... Once thermonuclear fusion in the center of a star is ignited, the star will heat up and become more luminous. Thus, which way will it “move” in the Hertzsprung-Russell (HR) diagram? ...
The star is moving away from earth
... wavelength of the light emitted by this object as the temperature increases? ...
... wavelength of the light emitted by this object as the temperature increases? ...