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Lecture 15: The Main Sequence
... against gravitational collapse. Higher pressure=higher temperatures. The higher temperatures lead to greater rates of nuclear fusion which means higher luminosity. Example: Low-mass Star (0.1 MSun) ...
... against gravitational collapse. Higher pressure=higher temperatures. The higher temperatures lead to greater rates of nuclear fusion which means higher luminosity. Example: Low-mass Star (0.1 MSun) ...
File
... CLASS COPY!!! CLASS COPY!!! CLASS COPY!!! CLASS COPY!!! HR STAR DIAGRAM OBJECTIVE: Compare a stars color, temperature, brightness, and size to its spectral class. PURPOSE: Plot stars according to brightness and temperature to create an HR diagram. PROCEDURES: 1. Study the star data table on the back ...
... CLASS COPY!!! CLASS COPY!!! CLASS COPY!!! CLASS COPY!!! HR STAR DIAGRAM OBJECTIVE: Compare a stars color, temperature, brightness, and size to its spectral class. PURPOSE: Plot stars according to brightness and temperature to create an HR diagram. PROCEDURES: 1. Study the star data table on the back ...
THERMAL STABILITY OF LOW MASS STARS
... The sequence of stars in thermal equilibrium may be extended beyond the point defined with equation (ts.30). However, while the stellar radius may still decrease, the stellar mass will increase. Therefore, for masses somewhat above the minimum mass there are two different equilibrium models: one on ...
... The sequence of stars in thermal equilibrium may be extended beyond the point defined with equation (ts.30). However, while the stellar radius may still decrease, the stellar mass will increase. Therefore, for masses somewhat above the minimum mass there are two different equilibrium models: one on ...
Unit 1
... – Most have surface temperatures of ~5000K, so appear yellow – Most are giants (Yellow Giants) – Instability comes from partial absorption of radiation in the interior of the star • Helium absorbs radiation, and the outer layers of the star get pushed away from core • As the star expands, the densit ...
... – Most have surface temperatures of ~5000K, so appear yellow – Most are giants (Yellow Giants) – Instability comes from partial absorption of radiation in the interior of the star • Helium absorbs radiation, and the outer layers of the star get pushed away from core • As the star expands, the densit ...
Lecture13 - University of Waterloo
... • Because of the relative slow burning of hydrogen, the structure of the star changes only slowly with time. In general, the central temperature is higher for more massive stars ...
... • Because of the relative slow burning of hydrogen, the structure of the star changes only slowly with time. In general, the central temperature is higher for more massive stars ...
Astronomy 120
... The Stars as Suns Use a calculator whenever necessary. For full credit, always show your work and explain how you got your answer. Be careful about units! Please CIRCLE or put a box around your final answer if it is numerical. 1. Zeilik Study Exercise 13.1 In the winter sky, you see the following st ...
... The Stars as Suns Use a calculator whenever necessary. For full credit, always show your work and explain how you got your answer. Be careful about units! Please CIRCLE or put a box around your final answer if it is numerical. 1. Zeilik Study Exercise 13.1 In the winter sky, you see the following st ...
STUDY GUIDE FOR CHAPTER 1
... A. It is a plot of luminosity versus temperature for stars 1. Which direction does temperature increase in? Luminosity? 2. What can we plot instead of temperature? Instead of luminosity? B. Different types of stars are in different regions. You should know what types they are and what regions of the ...
... A. It is a plot of luminosity versus temperature for stars 1. Which direction does temperature increase in? Luminosity? 2. What can we plot instead of temperature? Instead of luminosity? B. Different types of stars are in different regions. You should know what types they are and what regions of the ...
HR Diagrams
... a. Based on your plot, does temperature of a star relate to its mass? Why or why not? b. What is the shape of the graph? What type of relationship does this indicate? 7. Repeat this process to determine the relationship exist between: a. Luminosity and colour? b. Radius and mass? c. Mass and colour? ...
... a. Based on your plot, does temperature of a star relate to its mass? Why or why not? b. What is the shape of the graph? What type of relationship does this indicate? 7. Repeat this process to determine the relationship exist between: a. Luminosity and colour? b. Radius and mass? c. Mass and colour? ...
Stars with mass less than 0.5 solar masses
... helium. This star is going to die in a white dwarf. These are little stars, very hot initially, which cool slowly till they swich off completely, in black ...
... helium. This star is going to die in a white dwarf. These are little stars, very hot initially, which cool slowly till they swich off completely, in black ...
LAB: Star Classification
... KPD 0005+5106. The team who present these observations show that this white dwarf is among the hottest stars known so far, with a temperature of 200,000º K at its surface. Stars of intermediate mass (1-8 solar masses) terminate their life as an Earth-sized white dwarf after the exhaustion of their n ...
... KPD 0005+5106. The team who present these observations show that this white dwarf is among the hottest stars known so far, with a temperature of 200,000º K at its surface. Stars of intermediate mass (1-8 solar masses) terminate their life as an Earth-sized white dwarf after the exhaustion of their n ...
Lecture12
... From the ideal gas law: if gas is in approximate pressure equilibrium (i.e. not expanding or contracting) then pockets of gas that are hotter than their surroundings will also be less dense. ...
... From the ideal gas law: if gas is in approximate pressure equilibrium (i.e. not expanding or contracting) then pockets of gas that are hotter than their surroundings will also be less dense. ...
Nuclear Astrophysics
... First thing is to average over the stellar temperature. And remember, the temperature of the ideal gas and photon gas are the same. However, the photon gas pressure depends only on the temperature (not on density), so there seems like a good place to start. ...
... First thing is to average over the stellar temperature. And remember, the temperature of the ideal gas and photon gas are the same. However, the photon gas pressure depends only on the temperature (not on density), so there seems like a good place to start. ...
Stars: the Hertzsprung
... stars is that there is only one way to make a star with a given mass and chemical composition – if we start with a just formed protostar of a given mass and chemical composition, we can calculate how that star will evolve over its entire life. • This is extremely useful because it greatly simplifies ...
... stars is that there is only one way to make a star with a given mass and chemical composition – if we start with a just formed protostar of a given mass and chemical composition, we can calculate how that star will evolve over its entire life. • This is extremely useful because it greatly simplifies ...
STELLAR EVOLUTION
... Stellar “evolution” describes the change in luminosity, surface temperature, and size of stars with time. This evolution is studied using the HR diagram. Stars evolve because they consume their nuclear “fuel", forcing changes in their internal structure, until they are no longer capable of continuin ...
... Stellar “evolution” describes the change in luminosity, surface temperature, and size of stars with time. This evolution is studied using the HR diagram. Stars evolve because they consume their nuclear “fuel", forcing changes in their internal structure, until they are no longer capable of continuin ...
Day 1212
... Giants and Dwarfs A supernova is a gigantic explosion in which the temperature in the collapsing core reaches 10 billion K and atomic nuclei are split into neutrons and protons. When very massive stars, with masses greater than 25 times that of the Sun, collapse past the neutron-star stage, they fo ...
... Giants and Dwarfs A supernova is a gigantic explosion in which the temperature in the collapsing core reaches 10 billion K and atomic nuclei are split into neutrons and protons. When very massive stars, with masses greater than 25 times that of the Sun, collapse past the neutron-star stage, they fo ...
Notes: Star Formation
... • The cloud of particles in a nebula begins to collapse because of gravity. – As the cloud collapses its temperature and density increase. – Temperature and density are the highest in the center of the cloud. – protostar- a dense area of gasses in a nebula that might become a star. ...
... • The cloud of particles in a nebula begins to collapse because of gravity. – As the cloud collapses its temperature and density increase. – Temperature and density are the highest in the center of the cloud. – protostar- a dense area of gasses in a nebula that might become a star. ...
White Dwarf Stars After nuclear burning ceases, a post
... pulsations, the amplitudes involved are not large enough to be detectable. The exception occurs in extremely massive (M > 90M⊙ ) stars, where the sensitivity of the ϵ-mechanism to temperature is enough to cause large oscillations and possibly disrupt the star. Under most circumstances, stars have Kr ...
... pulsations, the amplitudes involved are not large enough to be detectable. The exception occurs in extremely massive (M > 90M⊙ ) stars, where the sensitivity of the ϵ-mechanism to temperature is enough to cause large oscillations and possibly disrupt the star. Under most circumstances, stars have Kr ...
The Birth of Stars
... Sometimes (especially in spiral arms), the gas is compressed enough that the dust is thick and gravity can collapse knots in these “molecular” clouds to make new stars. ...
... Sometimes (especially in spiral arms), the gas is compressed enough that the dust is thick and gravity can collapse knots in these “molecular” clouds to make new stars. ...
HAYASHI LIMIT
... To the right of the Hayashi limit no stars in a hydrostatic equilibrium can exist. ...
... To the right of the Hayashi limit no stars in a hydrostatic equilibrium can exist. ...
Lecture 31 - 2 The Death of Stars: Stellar Recycling Phase 3 -
... Once all of the Hydrogen has been converted to Helium in the star’s core, thermonuclear reactions stop and for the moment there is no internal energy output that can counteract the always present inward pull of the star’s gravity. The pure Helium core now behaves separately from the surrounding laye ...
... Once all of the Hydrogen has been converted to Helium in the star’s core, thermonuclear reactions stop and for the moment there is no internal energy output that can counteract the always present inward pull of the star’s gravity. The pure Helium core now behaves separately from the surrounding laye ...
HR diagram
... This diagram is a plot of stellar brightness (luminosity) versus stellar color (temperature). Brightness (luminosity) is plotted along the Y-axis; color (temperature) along the X-axis. The diagram is named for the two astronomers who created the first version around 1912, uncovering fundamental rela ...
... This diagram is a plot of stellar brightness (luminosity) versus stellar color (temperature). Brightness (luminosity) is plotted along the Y-axis; color (temperature) along the X-axis. The diagram is named for the two astronomers who created the first version around 1912, uncovering fundamental rela ...
2.5.2 development of a star
... During this time it is stable as the gravitational forces that enable hydrogen burning balance and pull the star in, balance with the gas pressure pushing out. This is much like the gas pressure inside a balloon balancing with the tension in the plastic of the balloon. In the star it is known ...
... During this time it is stable as the gravitational forces that enable hydrogen burning balance and pull the star in, balance with the gas pressure pushing out. This is much like the gas pressure inside a balloon balancing with the tension in the plastic of the balloon. In the star it is known ...