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Definition
| Electrons stripped from atoms by high temperature. Stars are made of this. |
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| Amount of light energy received. Effect of inverse-square law. |
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| A star system that contains two stars. |
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| Gravity balanced by pressure. |
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| Giant clouds of molecular gas. Low temp. high density. Mostly H2, also CO, Methane, Ammonia and Water. Sites of star formation. |
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| The hot, compact corpses of low-mass stars, typically with a mass similar to the Sun compressed to a volume the size of Earth. |
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| The maximum possible mass for a white dwarf, which is about 1.4MvSun. |
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| A neutron star from which we see rapid pulses of radiation as it rotates. |
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| Used both as the name of our galaxy and to refer to the band of light we see in the sky when we look into the plane of the Milky Way Galaxy. |
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| Vaulted loops of hot gas that rise above the Sun's surface and follow magnetic field lines. |
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| Intrinsic Brightness (Luminosity) |
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Definition
| Total amount of light energy produced. |
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| Change in brightness with time. (Ex. Eclipsing Binary) |
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| A graph potting individual stars as points, with stellar luminosity on the vertical axis and spectral type (or surface temperature) on the horizontal axis. (See Diagram) |
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| Stars that appear just below the supergiants on the H-R diagram because they are somewhat smaller in radius and lower in luminosity. |
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Definition
| The glowing cloud of gas ejected from a low-mass star at the end of its life. |
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Definition
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| The nearest large spiral galaxy to the Milky Way. |
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Definition
| Blotches on the surface of the Sun that appear darker than surrounding regions. |
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| A way of classifying a star by the lines that appear in its spectrum; it is related to surface temperature. The basic spectral types are designated by a letter (OBAFGKM, with O for the hottest stars and M for the coolest) and are subdivided with numbers from 0-9. |
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| The dramatic brightening of a star that lasts for a few weeks and then subsides; occurs when a burst of hydrogen fusion ignites in a shell on the surface of an accreting white dwarf in a binary star system. |
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Definition
| The prominent line of points running from the upper left to the lower right on an H-R diagram; main-sequence stars shine by fusing hydrogen in their cores. |
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| An object too small to become an ordinary star because electron degeneracy pressure halts its gravitational collapse before fusion becomes self-sustaining; brown dwarfts have mass less than 0.08vSun. |
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Definition
| The very large and very bright stars that appear at the top of an H-R diagram. |
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| The compact corpse of a high-mass star left over after a supernova; typically contains a mass comparable to the mass of the Sun in a volume just a few kilometers in radius. |
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| A supernova witnessed on Earth in 1987; it was the nearest supernova seen in nearly 400 years and helped astronomers refine theories of supernovae. |
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| Galaxies that look like flat, white disks with yellowish bulges at their centers. The disks are filled with cool gas and dust, interspersed with hotter ionized gas, and usually display beautiful spiral arms. |
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Term
| Draw and label a cutaway diagram of the Sun and its extended atmosphere. Indicate the temperature at key points in its structure. |
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Definition
| http://www.fas.org/irp/imint/docs/rst/Sect20/h_sun_inside_001020_03.jpg |
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| How is energy produced from the thermonuclear reactions at the center of the Sun? How are the strong nuclear force, the electromagnetic force and the temperature involved? |
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Definition
| H fusion produces He, particles and energy. Mass of input-mass of output = energy released.Fusion = 4H combined ---> 1 He + Energy + Particles. Positive charges held together by strong nuclear force. |
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Term
| How does the parallax of a star allow us to determine its distance? Draw a diagram to illustrate your answer. |
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Definition
| Distance from triangulation. http://universe-review.ca/I02-07-parallax.jpg |
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Term
| Draw the light curve of an eclipsing binary. Draw a picture showing the positions of the stars during and in-between eclipses. How do the radial velocities of binary stars change over a complete cycle? |
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Definition
| http://csep10.phys.utk.edu/astr162/lect/binaries/eclipsing/eclipse.gif |
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| Draw and label a Hertzsprung-Russell diagram. List the spectral types in order from hottest to coolest. How do the properties of stars change from one end of the main sequence to the other? |
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Definition
| Low end=low luminocity=masses are low. High end=high luminocity=very massive. O and B type stars have very short lifetimes because they burn it fast. K or M live for a LOOOONNNNNGGG time. |
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| How can we use the HR-diagram and the equation L = 4πR2σT4 to infer the radii of stars? |
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Definition
| We know L and T from the HR diagram so we just have to figure out R. |
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Term
| What are the differences between globular and open clusters? |
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Definition
| G= old and dense packed clusters. O= loosely packed and young groups of stars. |
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Term
Draw the evolutionary track of a low mass star from protostar to white dwarf on the
HR diagram. Label the points of the most significant events in the course of its lifetime. |
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Definition
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| What are the end states of a low mass star and a high mass star? |
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Definition
Low mass - dies becomes white dwarf
High mass - explodes as a supernova |
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| How does the production of an iron core in the evolution of a high mass star result in a supernova explosion? What happens in a white-dwarf supernova? |
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Definition
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Term
| Draw a picture of the Milky Way galaxy as it might appear from outside and label all of its parts. How are globular clusters distributed within the Milky Way? How are open clusters distributed? |
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Definition
| G= old and dense packed clusters. O= loosely packed and young groups of stars. |
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Term
| What is the evidence that Mars once had running water? Why is this fact important? |
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Definition
| Valleys and minerals that can only be formed in standing water. River beds. Temp had to have been moderate at one point in time. |
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Term
Describe the two techniques for detecting and determining the masses of extra-solar
planets? |
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Definition
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Term
| What properties of extra-solar planets make them difficult to understand, in the context of the Nebular Hypothesis? How might these problems be explained? |
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Definition
| Extra solar big planets are very close to the star they are orbiting so they are very hot. Jovian planets cannot form inside the frost line so it must have formed outside and then moved in. |
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| Why is Europa considered a (remotely) possible site for the evolution of life? |
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Definition
| Europa has an icy coating but on the inside there is liquid |
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