Astro 10 Practice Test 2
... c. The smaller, less luminous star would show an emission spectrum, whereas the larger, more luminous star would show an absorption spectrum. d. The hotter star would show more absorption lines, while the cooler star would show fewer absorption lines. ...
... c. The smaller, less luminous star would show an emission spectrum, whereas the larger, more luminous star would show an absorption spectrum. d. The hotter star would show more absorption lines, while the cooler star would show fewer absorption lines. ...
(HR) Diagrams
... 16. Add labels and lines (mostly curves, actually) with arrows on the end of each (curvy) line, to show how a star such as the sun (a G2 star while it is on the main sequence) evolves through the following stages: a. protostar (which may have formed in a Bok globule) to main sequence star b. main se ...
... 16. Add labels and lines (mostly curves, actually) with arrows on the end of each (curvy) line, to show how a star such as the sun (a G2 star while it is on the main sequence) evolves through the following stages: a. protostar (which may have formed in a Bok globule) to main sequence star b. main se ...
Stellar Evolution
... 100,000 times more luminous than the Sun but is only 3,500K on the surface. It’s radius is 1,000 times that of the Sun. ...
... 100,000 times more luminous than the Sun but is only 3,500K on the surface. It’s radius is 1,000 times that of the Sun. ...
Blackbody Radiation
... A neutral atom consists of a nucleus, made of protons and neutrons, and enough electrons to neutralize the positive charge of the protons. The diameter of the nucleus is about 1 femtometer (1 fm = 10-15m). ...
... A neutral atom consists of a nucleus, made of protons and neutrons, and enough electrons to neutralize the positive charge of the protons. The diameter of the nucleus is about 1 femtometer (1 fm = 10-15m). ...
Astronomical Ideas Fall 2012 Homework 4 Solutions 1. Two stars
... that the cluster needs to be old enough so that all of the more massive stars have already burned up all of their Hydrogen and left the main sequence. ...
... that the cluster needs to be old enough so that all of the more massive stars have already burned up all of their Hydrogen and left the main sequence. ...
G-stars - Gemini Astronomie
... The birth of a star: Every star develops from a cloud (giant molecular cloud GMC) consisting almost entirely of the elements hydrogen and helium with a small percentage of other elements as well as dust, mostly from the death of older stars. Due to the force of its own gravity, the cloud begins to c ...
... The birth of a star: Every star develops from a cloud (giant molecular cloud GMC) consisting almost entirely of the elements hydrogen and helium with a small percentage of other elements as well as dust, mostly from the death of older stars. Due to the force of its own gravity, the cloud begins to c ...
Eksamination in FY2450 Astrophysics Wednesday June 8
... Many students claim that what we see on the surface of the star is directly influenced by fusion processes producing new elements. Such ideas are wrong. Except for white dwarfs and neutron stars, it is only deep inside a star that temperatures and densities are high enough for fusion processes to ta ...
... Many students claim that what we see on the surface of the star is directly influenced by fusion processes producing new elements. Such ideas are wrong. Except for white dwarfs and neutron stars, it is only deep inside a star that temperatures and densities are high enough for fusion processes to ta ...
Islip Invitational 2013 Astronomy Examination Student
... a. Are slightly blueshifted. b. Are the same. c. Are slightly redshifted. d. Have different sets of spectral lines. e. Have the same sets of spectral lines but different widths for those lines. 10. Suppose you see two stars: a blue star and a red star. Which of the following can you conclude about t ...
... a. Are slightly blueshifted. b. Are the same. c. Are slightly redshifted. d. Have different sets of spectral lines. e. Have the same sets of spectral lines but different widths for those lines. 10. Suppose you see two stars: a blue star and a red star. Which of the following can you conclude about t ...
What is light?
... But, where does light actually come from? Light comes from the acceleration of charged particles (such as electrons and protons) ...
... But, where does light actually come from? Light comes from the acceleration of charged particles (such as electrons and protons) ...
The Physics of Energy sources Stellar fusion
... ! Could you explain what is the source of energy of a Star? ! What is the proton-proton chain? ! Why can it work? ! What is the slowest process in this chain? ...
... ! Could you explain what is the source of energy of a Star? ! What is the proton-proton chain? ! Why can it work? ! What is the slowest process in this chain? ...
The Masses and Lifetimes of Stars
... The γ-rays do not escape the sun (the sun is opaque to γ-rays), but interact with other particles in the core. Eventually, the result is that each γ-ray is converted to many UV-optical-IR photons which do escape. Although it takes 170,000 yrs for the energy of each γ-ray to reach the surface from t ...
... The γ-rays do not escape the sun (the sun is opaque to γ-rays), but interact with other particles in the core. Eventually, the result is that each γ-ray is converted to many UV-optical-IR photons which do escape. Although it takes 170,000 yrs for the energy of each γ-ray to reach the surface from t ...
PHY320 Glossary of Terms - The University of Sheffield
... and 7Li. Measurements of the abundances of these nuclear species provides a valuable crosscheck on the standard model of the early evolution of the Universe. Red Giants are stars which have just left the main sequence after completing the consumption of hydrogen in their cores. They are thought to b ...
... and 7Li. Measurements of the abundances of these nuclear species provides a valuable crosscheck on the standard model of the early evolution of the Universe. Red Giants are stars which have just left the main sequence after completing the consumption of hydrogen in their cores. They are thought to b ...
Star Formation 1 - Center for Astrostatistics
... where n is the density of atoms, k is Boltzmann's constant, and T is the temperature (Ideal gas law, Boltzmann mid-1800s) So, the cloud of atoms starts gravitational collapse, gas heats up as density increase, and collapse stops when hydrostatic equilibriumis achieved; that is, when the inward pull ...
... where n is the density of atoms, k is Boltzmann's constant, and T is the temperature (Ideal gas law, Boltzmann mid-1800s) So, the cloud of atoms starts gravitational collapse, gas heats up as density increase, and collapse stops when hydrostatic equilibriumis achieved; that is, when the inward pull ...
Absolute magnitude
... to jump to a higher energy level. ▪ The photon’s energy must be equal to the energy difference between the two levels. ...
... to jump to a higher energy level. ▪ The photon’s energy must be equal to the energy difference between the two levels. ...
The winter triangle - NRC Publications Archive
... is annihilating 400,000 million tonnes of itself per second. Even though it has about 10 times the mass of the Sun, it is easy to see that it cannot keep this up for long. The Sun has been burning for around 4.5 billion years. Betelgeux cannot be more than about 10 million years old and is unlikely ...
... is annihilating 400,000 million tonnes of itself per second. Even though it has about 10 times the mass of the Sun, it is easy to see that it cannot keep this up for long. The Sun has been burning for around 4.5 billion years. Betelgeux cannot be more than about 10 million years old and is unlikely ...
–1– Homework 4 Solutions 1. Fun physics with mean molecular
... that the Hydrogen is in the form of molecular Hydrogen. Since the µbn > µJov , the resulting force will be negative, and the balloon will sink. 2. Determine the equation for the luminosity evolution of a main sequence star. The equation should be in terms of the initial luminosity and m at t=0, the ...
... that the Hydrogen is in the form of molecular Hydrogen. Since the µbn > µJov , the resulting force will be negative, and the balloon will sink. 2. Determine the equation for the luminosity evolution of a main sequence star. The equation should be in terms of the initial luminosity and m at t=0, the ...
Type II supernova
A Type II supernova (plural: supernovae or supernovas) results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, and no more than 40–50 times, the mass of the Sun (M☉) for this type of explosion. It is distinguished from other types of supernovae by the presence of hydrogen in its spectrum. Type II supernovae are mainly observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies.Stars generate energy by the nuclear fusion of elements. Unlike the Sun, massive stars possess the mass needed to fuse elements that have an atomic mass greater than hydrogen and helium, albeit at increasingly higher temperatures and pressures, causing increasingly shorter stellar life spans. The degeneracy pressure of electrons and the energy generated by these fusion reactions are sufficient to counter the force of gravity and prevent the star from collapsing, maintaining stellar equilibrium. The star fuses increasingly higher mass elements, starting with hydrogen and then helium, progressing up through the periodic table until a core of iron and nickel is produced. Fusion of iron or nickel produces no net energy output, so no further fusion can take place, leaving the nickel-iron core inert. Due to the lack of energy output allowing outward pressure, equilibrium is broken.When the mass of the inert core exceeds the Chandrasekhar limit of about 1.4 M☉, electron degeneracy alone is no longer sufficient to counter gravity and maintain stellar equilibrium. A cataclysmic implosion takes place within seconds, in which the outer core reaches an inward velocity of up to 23% of the speed of light and the inner core reaches temperatures of up to 100 billion kelvin. Neutrons and neutrinos are formed via reversed beta-decay, releasing about 1046 joules (100 foes) in a ten-second burst. The collapse is halted by neutron degeneracy, causing the implosion to rebound and bounce outward. The energy of this expanding shock wave is sufficient to accelerate the surrounding stellar material to escape velocity, forming a supernova explosion, while the shock wave and extremely high temperature and pressure briefly allow for theproduction of elements heavier than iron. Depending on initial size of the star, the remnants of the core form a neutron star or a black hole. Because of the underlying mechanism, the resulting nova is also described as a core-collapse supernova.There exist several categories of Type II supernova explosions, which are categorized based on the resulting light curve—a graph of luminosity versus time—following the explosion. Type II-L supernovae show a steady (linear) decline of the light curve following the explosion, whereas Type II-P display a period of slower decline (a plateau) in their light curve followed by a normal decay. Type Ib and Ic supernovae are a type of core-collapse supernova for a massive star that has shed its outer envelope of hydrogen and (for Type Ic) helium. As a result, they appear to be lacking in these elements.