ASTRONOMY 301 EXAMPLES OF TEST
... radio waves, infrared and blue light, ultraviolet radiation, and X-rays. all of the above. ...
... radio waves, infrared and blue light, ultraviolet radiation, and X-rays. all of the above. ...
Light and the Electromagnetic Spectrum Problems
... Because light gets blocked and scattered by dust and gas, it is sometimes helpful to look at the same object in different frequencies. Look at the images of the multiwavelength of the Milky Way. Each of these images is a picture of our Milky Way galaxy; we will see later that we are just one star i ...
... Because light gets blocked and scattered by dust and gas, it is sometimes helpful to look at the same object in different frequencies. Look at the images of the multiwavelength of the Milky Way. Each of these images is a picture of our Milky Way galaxy; we will see later that we are just one star i ...
Black Holes - Troy University
... BHs are not cosmic vacuum cleaners: only inside the horizon is matter pulled inexorably inward Far away from a BH, gravity is no different than for any other object with the same mass If a BH were to replace the sun, the orbits of planets, ...
... BHs are not cosmic vacuum cleaners: only inside the horizon is matter pulled inexorably inward Far away from a BH, gravity is no different than for any other object with the same mass If a BH were to replace the sun, the orbits of planets, ...
Stars (Ch. 13)
... • Since stars are so far away they almost always appear just as points of light. • But as we already know we can learn a lot from light! • Light can tell us about a star’s: ...
... • Since stars are so far away they almost always appear just as points of light. • But as we already know we can learn a lot from light! • Light can tell us about a star’s: ...
Can the sun make it rain, or (Will astronomy help us
... • Dust (grains) formed in cool parts of giant stars • Molecules formed on dust grains • Planets condensed from stellar environment • Biological processes differentiated elements ...
... • Dust (grains) formed in cool parts of giant stars • Molecules formed on dust grains • Planets condensed from stellar environment • Biological processes differentiated elements ...
Evolution of Population II Stars in the Helium
... some definite value, without mixing between the hydrogen-rich envelope and the helium region. Evolution of Population I stars with 15.6 M 0 4>, 5> and 4 M 0 6> in the heliumburning phase has been investigated taking into account the effect of helium depletion on the mean molecular weight and on the ...
... some definite value, without mixing between the hydrogen-rich envelope and the helium region. Evolution of Population I stars with 15.6 M 0 4>, 5> and 4 M 0 6> in the heliumburning phase has been investigated taking into account the effect of helium depletion on the mean molecular weight and on the ...
Document
... • Brightness: distance and energy output - Luminosity – total energy emitted by a star ...
... • Brightness: distance and energy output - Luminosity – total energy emitted by a star ...
PowerPoint Presentation - Super Massive Black Holes
... as the object gets more massive, the force should get bigger too. But the force is also inversely proportional to the cube of the object's radius. As the hole gets more massive, its size increases, but because of the cube factor, the force decreases much faster than any possible mass increase can ac ...
... as the object gets more massive, the force should get bigger too. But the force is also inversely proportional to the cube of the object's radius. As the hole gets more massive, its size increases, but because of the cube factor, the force decreases much faster than any possible mass increase can ac ...
pdf format
... We see that v is approximately constant in galaxies (does not depend on a). Therefore the Mass inside radius a increases linearly with a. ...
... We see that v is approximately constant in galaxies (does not depend on a). Therefore the Mass inside radius a increases linearly with a. ...
Neutron Stars
... • A nova is different from supernova (luminosity of 109 Lsun) • Material from an ordinary star in a close binary can fall onto the surface of the companion white dwarf • Because of strong gravity, the transferred hydrogen mass is compressed into a dense layer covering the while surface • When the te ...
... • A nova is different from supernova (luminosity of 109 Lsun) • Material from an ordinary star in a close binary can fall onto the surface of the companion white dwarf • Because of strong gravity, the transferred hydrogen mass is compressed into a dense layer covering the while surface • When the te ...
Where is the Sun in the Milk Way?
... Luminosity, Effec8ve Temperature, Flux and Magnitudes • What is Luminosity (L) of a star? – The luminosity of a star is defined as the radiaDve power output emanaDng from its surface, in other words, ...
... Luminosity, Effec8ve Temperature, Flux and Magnitudes • What is Luminosity (L) of a star? – The luminosity of a star is defined as the radiaDve power output emanaDng from its surface, in other words, ...
The Interstellar Medium Molecular clouds Stellar halo Bulge (= bar)
... Matthew Bate, University of Exeter UK ...
... Matthew Bate, University of Exeter UK ...
v3 Long theoretical questions Instructions 1. You will receive in your
... 1. A transit of duration 180 minutes was observed for a planet which orbits the star HD209458 with a period of 84 hours. The Doppler shift of absorption lines arising in the planet's atmosphere was also measured, corresponding to a difference in radial velocity of 30 km/s (with respect to observer) ...
... 1. A transit of duration 180 minutes was observed for a planet which orbits the star HD209458 with a period of 84 hours. The Doppler shift of absorption lines arising in the planet's atmosphere was also measured, corresponding to a difference in radial velocity of 30 km/s (with respect to observer) ...
Lecture 21
... The opacity is more sensitive to the temperature than to the density, so the opacity usually decreases with compression (heat leaks out). But in a partial ionization zone, the energy of compression ionizes the stellar material rather than raising its temperature! In a partial ionization zone, the op ...
... The opacity is more sensitive to the temperature than to the density, so the opacity usually decreases with compression (heat leaks out). But in a partial ionization zone, the energy of compression ionizes the stellar material rather than raising its temperature! In a partial ionization zone, the op ...
Lecture 13 Presupernova Models, Core Collapse and Bounce
... Original model due to Miyaji et al (1980). Studied many times since. A similar evolution may occur for accreting Ne-O white dwarfs (or very rapidly accreting CO-white dwarfs) in binary systems - an alternate outcome to Type Ia supernovae. This phenomena in a binary is generally referred to as Accre ...
... Original model due to Miyaji et al (1980). Studied many times since. A similar evolution may occur for accreting Ne-O white dwarfs (or very rapidly accreting CO-white dwarfs) in binary systems - an alternate outcome to Type Ia supernovae. This phenomena in a binary is generally referred to as Accre ...
Publisher: Emily Barrosse Acquisitions Editor: Kelley Tyner
... then fuse with a helium nucleus (alpha particle) to form oxygen. The carbon– oxygen core of a supergiant contracts, heats up, and begins fusing into still heavier elements. The ashes of one set of nuclear reactions become the fuel for the next set. Each stage of fusion gives off energy. Finally, eve ...
... then fuse with a helium nucleus (alpha particle) to form oxygen. The carbon– oxygen core of a supergiant contracts, heats up, and begins fusing into still heavier elements. The ashes of one set of nuclear reactions become the fuel for the next set. Each stage of fusion gives off energy. Finally, eve ...
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.