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103 Cards in this Set
- Front
- Back
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Name the three types of Binaries |
visual binaries eclipsing binary spectrographic binary |
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What is absolute magnitude |
the brighness of a star at 10 parsecs |
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What is visual magnitude |
The brightness of a star from earth |
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What do spectral lines show us? |
the presence of different elements in the sun |
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What is the average density of the close to ? |
a little bit denser than water |
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What is a result of the change in motion of a charged particle? |
Electromagnetic radiation |
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What is absolute zero? |
The temperature at which all thermal motion stops 0 kelvin or -273C |
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What is black body radiation? |
The radiation emitted by an opaque object, with a continuous spectrum |
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What is wavelength of maximum intensity |
The wavelength which is emitted by maximum amount of energy of an object with a certain temperature |
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What is Wiens law |
the hotter an object is the shorter its wavelength of maximum intensity |
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What is the stefan boltzman law |
Hotter objects emit more energy than cooler objects of the same size |
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What is the apperant surface of the sun called |
photosphere |
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What to things keep the sun from exploding/contracting |
preassure and temperature |
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What does the strong force do |
binds protons and neutrons together to form a nucleus |
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What is the name of the process by which the Sun turns mass into energy? |
fusion |
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Why does the proton-proton chain need high temperatures? |
High temperatures increase the velocity of the protons so they can overcome the Coulomb barrier |
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What is a sunspot |
Relatively cooler dark spots on the sun that contains intense magnetic fields |
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What is granulation |
the grainy surface if the photosphere with dark edges due to convection |
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What is the columb force |
The attraction between between the negatively charged electrons and positive charge of the nucleus |
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What is an ion |
an atom that has lost or gained one or more electrons |
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What is binding energy |
energy needed to pull an elecotron away from its atom |
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what does overcoming binding energy result in |
ionization (process in which atoms gain or loose electrons |
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When does an atom become exited? |
When an electron is moved from a low energy level to a high energy level |
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What is the lowest energy level an electron can occur called? |
ground state |
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What does the color of a star determine |
its temperature |
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What color star is the coolest |
Red |
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In astronomy what does the doppler effect tell us |
If a star is redshifting (getting closer) or blue shifting (moving toward |
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What is produced in the proton proton chain |
helium nucleus, two neutrinos, and energy in the form of gamma rays |
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How did sudbury solve the missing nuetrino problem |
It showed that the "missing" neutrinos were changing into different types |
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What would happen if a stars core produced too little energy? |
it would shirnk/contract |
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How much of its lifetime does the average star spend on the main sequence? |
90% |
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What is the very start of the main sequence called? (ZAMS) |
zero age main sequence |
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Why do lower mass stars live longer |
They use less fuel slower |
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When is a star considered main sequence? |
When it begins fusion |
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What is steller parallax |
triangulation of close stars |
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For a star with a mass similar to that of the Sun, what is the last stage of the nuclear fusion? |
helium to carbon |
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Which of the following statements best describes why medium-mass stars eventually die? |
they cannot burn the ash that accumulates in their core |
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in order what is the lifecycle of a star like the sun from birth to death? |
protostar, main sequence star, red giant, planetary nebula, white dwarf |
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What is a sub atomic particle produced in the sun by fusion that can travel with little interction with anything else |
neutrinos |
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What does dueteruim consist of |
a proton and a neutron |
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What is the spectral sequence ranging from hot to cool |
O, B, A ,F, G, K, M Oh Be A Fine Girl Kiss Me |
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What does the limit of the main sequence on the lower end represent |
The minimum temperature of a star when fusion begins |
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What is the approximate mass of the lowest mass object that can initiate the thermonuclear fusion of hydrogen? |
0.08 solar masses |
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Ash |
Bae |
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What is a Bok Globules |
cold dense pockets of intersteller medium (ISM) that are warm enough to support their own weight |
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Proto stars evolve on the main sequence T or F |
F they evolve ON TO it |
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What is the weak nuclear force |
involved in the radioactive decay of certain kinds of of nuclear particles |
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What type of Hyrdrogen fusion do stars like our sun use? |
The proton proton chain |
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What type of fusion do upper main sequence more massive than the sun use? |
The carbon nitrogen oxygen or CNO cycle |
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What is a result of helium fusion |
Carbon |
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what is a result of hydrogen fusion |
helium |
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Who is a cutie Patootie? |
Ashley |
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What is the interstellar medium (ISM) |
the gas and dust distributed between the stars |
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What are the three types of sprectrums according to kirchoffs laws |
Continuous spectrum
Emission spectrum absorbtion spectrum |
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What is the continuous spectrum |
A solid, liquid, or dense gas exited to emit light will radiate at all wavelengths |
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What is the emission spectrum |
A low density gas excited to emit light will do so at specific wavelengths photons emittied by an exited gas produce emission lines |
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What is the absorption spectrum |
if light comprising a continuous spectrum passes through a cool, low density gas the result will be an absorption spectrum if radiation passes through a cool gas atoms in the gas absorb photons of certain wavelengths, which are missing from the spectrum and will appear as dark absorption lines |
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What is the balence between weight and preassure called |
Hydrostatic equilibrium |
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What is the densest part of the ISM |
Molecular clouds |
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How is a star formed from a gas cloud (nebula) |
A shock wave from a supernova, the birth of other stars or becoming compressed in spiral arms can disrupt and break clouds into fragments which then become dense enough to collapse under the influence of their own gravity and form stars |
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Why don't molecular clouds collapse by themselves? |
Because the thermal energy, turbulent gas and magnetic fields keep them together thermal engergy the main one |
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What is a stellar association and why does it occur? |
a group of stars that formed together but not bound together This occurs because cloud fragments form thousands of stars not just one |
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What is a proto star? |
A collapsing cloud of gas destined to become a star |
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What defines a giant star |
a star with 10 to 100 times the diameter of the sun |
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what defines a super giant star? |
A star with 100 to 1000 times the diameter of our sun |
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What is the horizontal branch? on the H-R diagram |
The location in the HR diagram of giant starts that are fusing helium |
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What is a super nova |
The result of an explosion of a star, a "new star" because it has transformed |
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How does a giant star have two locations of fusion? |
It has helium fusion in the core and hydrogen fusion fusion in the surrounding shell |
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If a post main sequence star has no nuclear reactions what is it |
A red giant |
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If a post main sequence star has fusion reactions what it it |
A yellow giant |
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The stars in Star clusters form randomly and constantly T or F |
False they all formed around the same time from the same gas cloud
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What advantage do low mass stars like red dwarfs have over higher mass stars like the sun |
They are completely convective and can use all the hydrogen throughout the star rather than just the hydrogen in their core |
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Every red dwarf in the universe from the beggining of time is still alive today |
True red dwarfs have a lifetime of 100+ billion years while the universe is only 13.8 billion years old |
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What is the sequence of Fusion in medium mass sunlike stars |
Hydrogen> Helium> Carbon- Oxygen ash |
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What are the abundant and second most abundant stars in the universe |
Red Dwarfs and white dwarfs |
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How do white dwarfs become so hot if their about the size of earth |
Gravitational energy is converted to thermal energy but they do not become hot enough to fuse carbon or oxygen |
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Why are whit dwarfs not true stars |
they do not genereate nuclear energy and is made almost completly degenerate matter |
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what is degenerate matter? |
high dense matter which preassure no longer depends on temperature (electrons cannot get closer together) |
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What is a compact object? |
when a steller object generates no nuclear energy and is much asmaller and denser than a normal star |
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What types of compact objects are their |
Neutron stars black holes and probably white dwarfs |
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What are the two types of star clusters |
Globular clusters Open clusters |
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What is an open cluster |
10 to 1000 stars spread apart |
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What is a globular clusters |
millions of old stars in a nearly spherical form |
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What is an accretion disk |
rotating disk that forms in some situations as matter is drawn gravitationally toward a central body |
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Why is a neutron star called a neutron star |
Because it is composed almost entirely of tightly packed neutrons |
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What are characteristics of neutron stars |
Spin rapidly are super hot (like ashley) have strong magnetic fields |
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What is a pulser |
A source of short precisely timed radiobusrsts understood to be spinnig neutron stars |
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Which singh can singh |
Ashley |
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What us the chandrasekhar-landau limit |
The limit degenerate electron pressure can support. 1.4 solar masses |
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how much longer will the sun liveÉ |
6 billion years |
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What are roche lobes |
the volume of space a star controls gravitationally within a binary system dumbbell shape of binary systems |
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what is a nova explosion and how and when does it occur? |
The explosion caused by fusion of a layer of hydrongen on a white dawrf. this layer of hydrogen is taken from a normal star into an accretion disk of a white dwarf (which will loose angular monmentum and create a layer of hyrdogen on the white dwarf) |
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What is a type Ia supernova? |
Occurs when a white dwarf in a binary system recives enough mass to exceed the chandrasekhar- landau limit (or 1.8 solar masses) and collapses |
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All supernovas leave a gas remmanant or nebula T or F |
F type Ia supernova do not |
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What is a "standard candle"? |
something that always has very similar (almost the same) characteristics |
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What can type Ia supernova be used for by astronomers? |
they can be used as a standard candle to indicate distances |
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How many hydrogen nuclei make one helium nucleus? |
Four |
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Who's not going to douglas? |
Ashley! |
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What is a type 2 supernova? |
The death of a massive star, mostly by the collapse of red supergiants, but can be other stars to |
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However a star lives it must leave behind one of three objects, which are? |
A white dwarf, nuetron star, or black hole |
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Stars more massive than 15 solar masses are expected to become? |
A black hole |
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Stars that begin life on the main sequence with 8 to 15 solar masses are expected to become |
Nuetron stars |
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What is in Dylan's stomach? |
Laksa |
