
Ay 101 - The Physics of Stars – fall 2015 -... Homework 1, due Friday Oct 9 at class (2 pm)
... fractions: f1 = 0.10, f2 = 0.85, and f3 = 0.05. Their partition functions (degeneracies) are g1 = 1, g2 = 2, g3 = 8. The ionization energy from the fundamental level for ion 1 is 30 eV, and it is 55 eV for ion 2. Calculate ne and T . 2. (10 points) Calculate (approximately) for the Sun the gravitati ...
... fractions: f1 = 0.10, f2 = 0.85, and f3 = 0.05. Their partition functions (degeneracies) are g1 = 1, g2 = 2, g3 = 8. The ionization energy from the fundamental level for ion 1 is 30 eV, and it is 55 eV for ion 2. Calculate ne and T . 2. (10 points) Calculate (approximately) for the Sun the gravitati ...
Star formation and lifetimes
... • As the gas cloud collapses due to gravitational forces, the core becomes hotter and the density inside the core increases • Eventually, the temperature and density reach a point where nuclear fusion can occur ...
... • As the gas cloud collapses due to gravitational forces, the core becomes hotter and the density inside the core increases • Eventually, the temperature and density reach a point where nuclear fusion can occur ...
HNRS 227 Lecture #2 Chapters 2 and 3
... Core hydrogen fusion ceases when the hydrogen has been exhausted in the core of a main-sequence star This leaves a core of nearly pure helium surrounded by a shell through which hydrogen fusion works its way outward in the star The core shrinks and becomes hotter, while the star’s outer layers ...
... Core hydrogen fusion ceases when the hydrogen has been exhausted in the core of a main-sequence star This leaves a core of nearly pure helium surrounded by a shell through which hydrogen fusion works its way outward in the star The core shrinks and becomes hotter, while the star’s outer layers ...
Introduction to Astronomy
... • The full range of masses occurs among mainsequence stars, for which mass correlates to temperature and luminosity. • “Red giant” stars tend to be more massive than our sun, but otherwise are no more massive than main-sequence stars. • “White dwarf” stars tend to have about the same mass as our sun ...
... • The full range of masses occurs among mainsequence stars, for which mass correlates to temperature and luminosity. • “Red giant” stars tend to be more massive than our sun, but otherwise are no more massive than main-sequence stars. • “White dwarf” stars tend to have about the same mass as our sun ...
Answer all questions in Section A and two and only two questions in
... for which the gas and radiation pressure contribute equally in the core, assuming the Clayton model is an accurate description. ...
... for which the gas and radiation pressure contribute equally in the core, assuming the Clayton model is an accurate description. ...
How is a Star`s Color Related to Its temperature?
... different colors. Rigel is blue. and Betelgense is red. Capella and ore" Sun are yellow, in this activity you will make your own Hertzsprung-Russell diagram. You will see how star brightness, color. temperature, and class are related. ~Vlaterials: Colored pencils (red, orange, yellow, blue) Procedur ...
... different colors. Rigel is blue. and Betelgense is red. Capella and ore" Sun are yellow, in this activity you will make your own Hertzsprung-Russell diagram. You will see how star brightness, color. temperature, and class are related. ~Vlaterials: Colored pencils (red, orange, yellow, blue) Procedur ...
AST 301 Introduction to Astronomy - University of Texas Astronomy
... How does the life story of a massive star differ? For stars up to about 8 Msun, the story is like that for the Sun. It just runs faster. For each doubling of the mass, the luminosity goes up by about 10, so fusion must be running 10 times faster, so it uses up its fuel about 5 times faster. An 8 Ms ...
... How does the life story of a massive star differ? For stars up to about 8 Msun, the story is like that for the Sun. It just runs faster. For each doubling of the mass, the luminosity goes up by about 10, so fusion must be running 10 times faster, so it uses up its fuel about 5 times faster. An 8 Ms ...
The HLCO Project - High Legh Community Observatory
... The largest known star by volume is KW Sagitari which is a whopping 1500 times the size of our Sun The heaviest known star is R136A1 in the Tarantula Nebula which started life as a lumbering 320 times heavier than the Sun The hottest known stars belongs to a special class known as a ‘Wolf-Rayet’ and ...
... The largest known star by volume is KW Sagitari which is a whopping 1500 times the size of our Sun The heaviest known star is R136A1 in the Tarantula Nebula which started life as a lumbering 320 times heavier than the Sun The hottest known stars belongs to a special class known as a ‘Wolf-Rayet’ and ...
Size Color and Temperature
... than the Sun. If Betelgeuse replaced the Sun, it would fill space in our solar system well beyond Earth’s orbit. Because giant and supergiant stars have such huge surface areas to give off light, they are very bright. Betelgeuse is one of the brightest stars in the sky, even though it is 522 light-y ...
... than the Sun. If Betelgeuse replaced the Sun, it would fill space in our solar system well beyond Earth’s orbit. Because giant and supergiant stars have such huge surface areas to give off light, they are very bright. Betelgeuse is one of the brightest stars in the sky, even though it is 522 light-y ...
Classes 12 to 13 - physics.udel.edu
... 10-4 M☉). In the core the electrons have a large mean free path because almost all available energy levels in the Fermi ‘sea’ are filled. This results in a high thermal conductivity and the core is isothermal to a high degree. We can assign a unique temperature, Tc, to the core. Because the white dw ...
... 10-4 M☉). In the core the electrons have a large mean free path because almost all available energy levels in the Fermi ‘sea’ are filled. This results in a high thermal conductivity and the core is isothermal to a high degree. We can assign a unique temperature, Tc, to the core. Because the white dw ...
ASTR100 Class 01 - University of Maryland Department of
... What would happen to a protostar that formed without any rotation at all? A. Its jets would go in multiple directions. B. It would not have planets. C. It would be very bright in the infrared. D. It would not be round. ...
... What would happen to a protostar that formed without any rotation at all? A. Its jets would go in multiple directions. B. It would not have planets. C. It would be very bright in the infrared. D. It would not be round. ...
Stars and Their Life Cycles
... • all are parts of a binary system (two stars orbit around one another) • possible that brown dwarfs represent a lot of the mass in the universe ...
... • all are parts of a binary system (two stars orbit around one another) • possible that brown dwarfs represent a lot of the mass in the universe ...
Overview - School District of La Crosse
... A. condense out of a swirling cloud of dust and gas. 1. Orion nebula is an example a. very rarified vacuum- million time more rarified than those found on earth 1. a study of this gas helps understand how rarified gases act. 2. super condensed stars result is a very dense star where 1 tablespoon of ...
... A. condense out of a swirling cloud of dust and gas. 1. Orion nebula is an example a. very rarified vacuum- million time more rarified than those found on earth 1. a study of this gas helps understand how rarified gases act. 2. super condensed stars result is a very dense star where 1 tablespoon of ...
Stars
... The Nebula Hypothesis The solar system (planets, satellites, asteroids, comets, etc.) formed along with the Sun 4.5 Byr ago from the gravitational collapse of an interstellar cloud of gas and dust. The planets and Sun formed from the same reservoir of interstellar matter and are therefore composed ...
... The Nebula Hypothesis The solar system (planets, satellites, asteroids, comets, etc.) formed along with the Sun 4.5 Byr ago from the gravitational collapse of an interstellar cloud of gas and dust. The planets and Sun formed from the same reservoir of interstellar matter and are therefore composed ...
KOI-54 Claude Plymate There is a star system about 45 light years
... undistinguished 8th magnitude A star or was before the Kepler telescope took a close look. As it turns out, the system is anything but typical or uninteresting. KOI-54 has been found to be a close binary system, consisting of nearly twin A stars in highly eccentric (e = 0.83) 41.8 day orbits about t ...
... undistinguished 8th magnitude A star or was before the Kepler telescope took a close look. As it turns out, the system is anything but typical or uninteresting. KOI-54 has been found to be a close binary system, consisting of nearly twin A stars in highly eccentric (e = 0.83) 41.8 day orbits about t ...
Practice questions for Stars File
... 2. Describe the fuel use changes from birth to death for a black hole 3. Describe the fuel use changes from birth to death for a neutron star 4. Explain how the energy changes are involved in each of their life cycles from birth to death. 5. Explain how the gravity changes are related to the final s ...
... 2. Describe the fuel use changes from birth to death for a black hole 3. Describe the fuel use changes from birth to death for a neutron star 4. Explain how the energy changes are involved in each of their life cycles from birth to death. 5. Explain how the gravity changes are related to the final s ...
Class 12 : Star formation I : The Interstellar Medium (ISM)
... A gas cloud of density ρ and temperature T collapses if its mass is above a critical amount given by… ...
... A gas cloud of density ρ and temperature T collapses if its mass is above a critical amount given by… ...
Stellar evolution
Stellar evolution is the process by which a star changes during its lifetime. Depending on the mass of the star, this lifetime ranges from a few million years for the most massive to trillions of years for the least massive, which is considerably longer than the age of the universe. The table shows the lifetimes of stars as a function of their masses. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds. Over the course of millions of years, these protostars settle down into a state of equilibrium, becoming what is known as a main-sequence star.Nuclear fusion powers a star for most of its life. Initially the energy is generated by the fusion of hydrogen atoms at the core of the main-sequence star. Later, as the preponderance of atoms at the core becomes helium, stars like the Sun begin to fuse hydrogen along a spherical shell surrounding the core. This process causes the star to gradually grow in size, passing through the subgiant stage until it reaches the red giant phase. Stars with at least half the mass of the Sun can also begin to generate energy through the fusion of helium at their core, whereas more-massive stars can fuse heavier elements along a series of concentric shells. Once a star like the Sun has exhausted its nuclear fuel, its core collapses into a dense white dwarf and the outer layers are expelled as a planetary nebula. Stars with around ten or more times the mass of the Sun can explode in a supernova as their inert iron cores collapse into an extremely dense neutron star or black hole. Although the universe is not old enough for any of the smallest red dwarfs to have reached the end of their lives, stellar models suggest they will slowly become brighter and hotter before running out of hydrogen fuel and becoming low-mass white dwarfs.Stellar evolution is not studied by observing the life of a single star, as most stellar changes occur too slowly to be detected, even over many centuries. Instead, astrophysicists come to understand how stars evolve by observing numerous stars at various points in their lifetime, and by simulating stellar structure using computer models.In June 2015, astronomers reported evidence for Population III stars in the Cosmos Redshift 7 galaxy at z = 6.60. Such stars are likely to have existed in the very early universe (i.e., at high redshift), and may have started the production of chemical elements heavier than hydrogen that are needed for the later formation of planets and life as we know it.