Term
| Which stellar spectral type has strong molecular absorption lines in its optical spectrum? |
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Definition
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|
Term
| The total amount of power that a star radiates into space is called its |
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Definition
|
|
Term
| Our Sun is a star of spectral type |
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Definition
|
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Term
| A scientist claims that all red main sequence stars are 1 billion years old. What would prove this claim false? |
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Definition
| The discovery of a red main sequence star in a star cluster where the main sequence turnoff is about that of the Sun |
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|
Term
| Which cluster is most likely to be located in the halo of our galaxy? |
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Definition
| The diagram shows main sequence stars of spectral types G, K, and M, along with numerous giants and white dwarfs |
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Term
| On average, how fast do the plates move on Earth? |
|
Definition
| a few centimeters per year |
|
|
Term
| How have we been able to construct detailed maps of surface features on Venus? |
|
Definition
| by using radar from spacecraft that were sent to orbit Venus |
|
|
Term
| Why does Mars have more extreme season than Earth? |
|
Definition
| Because it has a more eccentric orbit |
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Term
| Which of the following does not provide evidence that Mars once had abundant liquid water on its surface |
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Definition
| The prescence of canali, discovered in the late 1800s by Giovanni Schiaparelli and mapped by Percival Lowell |
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|
Term
| Why is the sky blue on Earth? |
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Definition
| Because molecules scatter blue light more effectively than red light |
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|
Term
| What kind of thermal radiation does the Earth emit? |
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Definition
|
|
Term
| What is the Cassini division of Saturn's rings? |
|
Definition
| A large gap, visible from Earth, produce by an orbital resonance with the moon Mimas |
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Term
| According to our theory of solar system formation, why did Uranus and Neptune end up to be much less massive than Jupiter and Saturn? |
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Definition
| Particles in the solar nebula were more spread out at greater distances, so that accretion took longer and there was less time to pull in gas before the solar wind cleared the nebula |
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Term
| Which of the following statements about the moons of the jovian planets is not true? |
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Definition
| Most of the moons are large enough to be spherical in shape, but a few have the more potato-like shapes of asteroids |
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|
Term
| Why is Saturn almost as big as Jupiter, despite its smaller mass? |
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Definition
| Jupiter's greater mass compresses it more and increases its density |
|
|
Term
| What statement about Io is true? |
|
Definition
| It is the most volcanically active body in our solar system |
|
|
Term
| Uranus and Neptune have methane clouds but Jupiter and Saturn do not. What factor explains why? |
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Definition
| Temperatures on Jupiter and Saturn are too high for methane to condense |
|
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Term
|
Definition
| was not surprising because other Kuiper belt objects approaching the size of Pluto had already been discovered |
|
|
Term
| Where did comets that are now in the Oort cloud originally form? |
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Definition
|
|
Term
| Assume that the average rate of 1km sized asteroids hitting the earth is about 1 in every million years. The chance of earth being hit in the next 100 years is about: |
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Definition
|
|
Term
| What do astronomers mean when they refer to gaps in the asteroid belt between Mars and Jupiter? |
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Definition
| Asteroids seem to avoid certain orbits around the Sun, creating "gaps" in the orbits that asteroids can have. |
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|
Term
| Which of the following statements is not true? |
|
Definition
| Objects in the Kuiper belt are made mostly of rock and metal |
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|
Term
| Every second, the Sun converts about 600 million tons of hydrogen into 596 million tons of helium. The remaining 4 tons of mass is |
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Definition
| converted to a amount of energy equal to 4 million tons times the speed of light squared |
|
|
Term
| How can we measure the strength of magnetic fields on the Sun/ |
|
Definition
| By looking for the splitting of spectral lines in the Sun's spectrum |
|
|
Term
| The Sun's average surface temperature is about |
|
Definition
|
|
Term
| The spectral sequence sorts stars according to |
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Definition
|
|
Term
| Which of the following luminosity classes refers to stars on the main sequence? |
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Definition
|
|
Term
| Which of the following statements about spectral types of stars is true? |
|
Definition
| All of the above- Spectral type of a star can be used to determine its surface temperature, a star with a spectral type A is cooler then a star with a spec. type B., A star with spec type F2 is hotter than a star with spec type F3, The spec type of a star can be used to determine its color |
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|
Term
| Which 2 factors are most important to the existence of plate tectonics on Earth? |
|
Definition
| Mantle convection and a thin lithosphere |
|
|
Term
| Which in its gaseous form is not a greenhouse gas? |
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Definition
|
|
Term
| Which one's surface would you expect to be most crowded with impact craters? |
|
Definition
| Size: same as the Moon. Distance from earth: same as Mars. Rotation rate: once every 10 days |
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|
Term
| Which of the following gases is not a significant ingredient of the Jovian planet atmosphere? |
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Definition
|
|
Term
| Which is most important in explaining the tremendous tidal heating that occurs on Io? |
|
Definition
| Io orbits Jupiter on an elliptical orbit, due to orbital resonances with other satellites |
|
|
Term
| The last major dinosaurs were wiped out as a consequence of a major impact with Earth. All but the following is regarded as evidence for this: |
|
Definition
| Multiple historical accounts describe a planetary-level flood and a storm that wiped out most living things. |
|
|
Term
| Suppose you find a meteorite made almost entirely out of metal. What must be true? |
|
Definition
| Your meteorite is a fragment from the core of a large asteroid that shattered in a collision |
|
|
Term
| How is the sunspot cycle directly relevant to us here on Earth? |
|
Definition
| Coronal mass ejections and other activity associated with the sunspot cycle can disrupt communications and knock out sensitive electronic equipment |
|
|
Term
| On the HR diagram, which group represents stars with the longest main sequence lifetime? |
|
Definition
| Low luminosity and low temperature. Far right end of main sequence line |
|
|
Term
| How did the lunar maria form? |
|
Definition
| Large impacts fractured the Moon's lithosphere, allowing lava to fill the impact basins |
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|
Term
| Which of the following is required in order for a planet to have rings? |
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Definition
| The planet must have many small moons that orbit relatively close to the planet in its equatorial plane |
|
|
Term
| If the chance of the Earth being hit by a life-destroying asteroid over the course of 1 year is 1 in a million, what is the chance of being hit over 100 years? |
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Definition
|
|
Term
| Energy balance in the Sun refers to a balance between |
|
Definition
| the rate at which fusion generates energy in the Sun's core and the rate at which the Sun's surface radiates energy into space |
|
|
Term
| What group on the HR diagram has the largest radii? |
|
Definition
|
|
Term
| Where is most of the water on Mars? |
|
Definition
| in its polar caps and subsurface ground ice |
|
|
Term
| Which of the following is not a piece of evidence supporting the idea that Europa may have a subsurface ocean? |
|
Definition
| Astronomers have detected small lakes of liquid water on Europa's surface |
|
|
Term
| Which of the following gases absorbs ultraviolet light best? |
|
Definition
|
|
Term
| Which internal energy sources produce heat by converting gravitational potential energy into thermal energy? |
|
Definition
| Differentiation and accretion |
|
|
Term
| A terrestrial world's lithosphere is |
|
Definition
| a layer of relatively strong, rigid rock, encompassing the crust and part of the mantle |
|
|
Term
| Which of the following is the underlying reason why Venus has so little wind erosion? |
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Definition
|
|
Term
| If Earth were to warm up a bit, what would happen? |
|
Definition
| Carbonate materials would form in the oceans more rapidly, the atmospheric CO2 content would decrease, and the greenhouse effect would weaken |
|
|
Term
| Why does increasing the amount a greenhouse gas increase the temperature of a planet? |
|
Definition
| Greenhouse gases absorb infrared light |
|
|
Term
| Which things are affected by a magnetic field? |
|
Definition
| Charged particles or magnetized materials such as iron |
|
|
Term
| Which best describes tectonics? |
|
Definition
| the disruption of a planet's surface by internal stresses |
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|
Term
| Which Jovian planet should have the most extreme season changes? |
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Definition
|
|
Term
| What atmospheric constituent is responsible for the blue color of Uranus and Neptune? |
|
Definition
|
|
Term
| What statement about planetary rings is not true? |
|
Definition
| Saturn's rings formed along with its moons 4.6 billion years ago |
|
|
Term
| Which of the following statements comparing the jovian interiors is not thought to be true? |
|
Definition
| They all have the same exact set of internal layers, though these layers differ in size |
|
|
Term
| How does the strength of Jupiter's magnetic field compare to that of Earth's magnetic field? |
|
Definition
| Jupiter's mag field is about 20,000 times as strong as Earth's |
|
|
Term
| Which of the following is not the primary constituent of one of Jupiter's cloud layers? |
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Definition
|
|
Term
| Which best describes the internal layering of Jupiter, from the center outward? |
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Definition
| Core of rock, metal, and hydrogen; thick layer of metallic hydrogen; layer of liquid hydrogen; layer of gaseous hydrogen; cloud layer |
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|
Term
| The Huygens probe took numerous pictures as it descended to Titan's surface in 2005. What did they show? |
|
Definition
| Features or erosion, including what appeared to be dry river valleys and lakebeds |
|
|
Term
| Which statement about Saturn's rings is not true? |
|
Definition
| The rings must look the same today as they did shortly after Saturn formed |
|
|
Term
| Why do astronomers believe that Triton is a captured moon? |
|
Definition
| Triton orbits Neptune in a direction opposite that of Neptune's rotation |
|
|
Term
| What is the most abundant gas in Titan's atmosphere? |
|
Definition
|
|
Term
| Which best describes the composition of the particles forming Saturn's rings |
|
Definition
|
|
Term
| Which is most unlikely to be found on Titan? |
|
Definition
| Lakes of liquid water in the warmer equatorial regions? |
|
|
Term
| How do the size and mass of Jupiter's core compared to the size and mass of earth? |
|
Definition
| It is about the same size but it is 10 times more massive |
|
|
Term
| Why are there no impact craters on the surface of Io? |
|
Definition
| Io did have impact craters but they have all been buried in lava flows |
|
|
Term
| How do astronomers think Jupiter generates its internal heat? |
|
Definition
| by contracting, changing gravitational potential energy into thermal energy |
|
|
Term
| Why do the jovian planet interiors differ? |
|
Definition
| Accretion took longer further from the Sun, so the more distant planets formed their cores later and captured less gas from the solar nebula than the closer jovian planets |
|
|
Term
| What is not a general characteristic of the 4 jovian planets? |
|
Definition
| The are higher in average density than the terrestrial planets |
|
|
Term
| During the time that a comet passes through the inner solar system, the comet can appear quite bright because |
|
Definition
| sunlight reflects off the comet's tail and coma |
|
|
Term
| Among discovered meteorites, we have found some with all of the following origins except |
|
Definition
| being a fragment from Comet Halley |
|
|
Term
| Why do we sometimes observe asteroids at the distances of the gaps in the asteroid belt? |
|
Definition
| A gap is located at an average orbital distance, and asteroid orbits often have large eccentricities |
|
|
Term
| On average, how often do impacts large enough to produce mass extinction on earth occur? |
|
Definition
| Once every hundred million years |
|
|
Term
| Which of the following does not lend support to the idea that Pluto is a Kuiper belt object? |
|
Definition
| Pluto is smaller than many known comets, such as Halley's comet |
|
|
Term
| Which of the following objects are probably not located in the same general region of the solar system in which they originally formed? |
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Definition
|
|
Term
| What do asteroids and comets have in common? |
|
Definition
| Most are unchanged since their formation in the solar nebula |
|
|
Term
| The total number of comets orbiting the Sun is estimated to about |
|
Definition
|
|
Term
| Why didn't a planet form where the asteroid belt is now located? |
|
Definition
| Gravitational tugs from Jupiter prevented material from collecting together to form a planet |
|
|
Term
|
Definition
| The site of an asteroid impact that occurred in Siberia in 1908 |
|
|
Term
| What is the typical size of a comet's nucleus? |
|
Definition
|
|
Term
| Processed meteorites with high metal content probably are |
|
Definition
| chunks of the core of a larger asteroid that was shattered by a collision |
|
|
Term
| How do we test our computer models for the interior of the Sun? |
|
Definition
| Comparing model predictions to how the Sun actually vibrates |
|
|
Term
| Which is the best answer to the question "Why does the Sun shine" |
|
Definition
| AS the Sun was forming, gravitational contraction increased the Sun's temperature until the core became hot enough for nuclear fusion, which ever since has generated the heat that makes the Sun shine |
|
|
Term
| Sunspots are cooler then the surrounding gas in the photosphere because |
|
Definition
| strong magnetic fields slow convection and prevent hot plasma from entering the region |
|
|
Term
| By what process do nuclear power plants on the Earth generate energy? |
|
Definition
|
|
Term
| Which of the following statements about the sunspot cycle is not true? |
|
Definition
| The rate of nuclear fusion in the Sun peaks about every 11 years |
|
|
Term
| To estimate the central temperature of the Sun, scientists |
|
Definition
| use computer models to predict interior conditions |
|
|
Term
| Studies of solar vibrations have revealed that |
|
Definition
| our mathematical models of the solar interior are fairly accurate |
|
|
Term
| If the Sun's core suddenly shrank a little bit, what would happen in the Sun? |
|
Definition
| The core would heat up, fusion rates would increase, the core would re-expand |
|
|
Term
| Which best explains why nuclear fusion requires bringing nuclei extremely close together? |
|
Definition
| Nuceli normally repel because they are all postively charged and can be made to stick only when brought close enough for the strong force to take hold |
|
|
Term
| Which of the following statements is an inference from a model? |
|
Definition
| The Sun's core is gradually turning hydrogen into helium |
|
|
Term
| How do we know how old the Sun is? |
|
Definition
| From ages of solar system meteorites, based on radioactive elements |
|
|
Term
| The proton-proton chain is |
|
Definition
| the specific set of nuclear reactions through which the Sun fuses hydrogen into Helium |
|
|
Term
| What happens to energy in the Sun's convection zone? |
|
Definition
| Energy is transported outward by the rising of hot plasma and sinking of cooler plasma? |
|
|
Term
| Which of the following is the most numerous type of main-sequence star? |
|
Definition
|
|
Term
| How did astronomers discover the relationship between spectral type and mass for main sequence stars? |
|
Definition
| By measuring the masses and spectral types of main-sequence stars in binary systems |
|
|
Term
| On the main sequence, stars obtain their energy |
|
Definition
| by converting hydrogen to helium |
|
|
Term
| Since all stars begin their lives with the same basic composition, what characteristic determines how they differ? |
|
Definition
| mass they are formed with |
|
|
Term
| On a H-R diagram, where would you find red giant stars? |
|
Definition
|
|
Term
| An O star has a hotter surface temperature than the Sun. Therefore, compared to the Sun, |
|
Definition
| its emission peaks in the blue part of the spectrum |
|
|
Term
|
Definition
| highest density, consists of metals- nickel and iron |
|
|
Term
|
Definition
| moderate density, rocky material consisted of minerals (silicon and oxygen). this is very thick |
|
|
Term
|
Definition
| lowest density, thin crust representing an outer skin- granite and basalt |
|
|
Term
|
Definition
| when gravity pulls the densest material to the bottom and drives less dense material up- results in layers made of different materials |
|
|
Term
|
Definition
| the process by which hot material expands and rises while cool material contracts and falls |
|
|
Term
| What explains our atmosphere and oceans? |
|
Definition
| Volcanism- water and gases became trapped beneath the surface and were released by volcanic eruptions called outgassing |
|
|
Term
|
Definition
| keeps earth's surface much warmer, allowing water to stay liquid on most of the surface. slows the escape of infrared light radiated by the planet |
|
|
Term
| Why did Mar's atmosphere change? |
|
Definition
| Lost atmospheric gas because of solar wind. Also lost its magnetic field and protective magnetosphere and along with water molecules |
|
|
Term
| How does Venus differ from Earth? |
|
Definition
| they are both geologically active but Venus lacks erosion and plate tectonics |
|
|
Term
| What is the most important factor in planetary cooling? |
|
Definition
| Size - large potato retains heat longer then a small potato, same with the planets |
|
|
Term
| What are Jovian planets made of? |
|
Definition
Jupiter and Saturn- almost entirely of hydrogen and helium
Uranus and Neptune- hydrogen compounds mixed with metal and rock |
|
|
Term
| What are Jovian planets like on the inside? |
|
Definition
| Layered interiors with very high internal temperatures and pressures. All have a core 10x as massive as Earth. |
|
|
Term
|
Definition
| only moon in our solar system that has a thick atmosphere. One of Saturn's moons. There is evidence of active surface geology including erosion caused by methane rain. |
|
|
Term
|
Definition
| orbits Neptune, is probably a captured object, rotates backwards, shows evidence of recent geological activity |
|
|
Term
|
Definition
| ongoing process that heats the interior of Io, arises from effects of tidal forces exerted by Jupiter. |
|
|
Term
| What are shapes of small Jovian moons? |
|
Definition
| Resemble potatoes because their gravities are too weak to force their rigid material into spheres |
|
|
Term
|
Definition
| slightly elliptical because of orbital resonances from the Galilean moons. This leads to tidal heating which makes Io volcanically active |
|
|
Term
| What are Saturn's rings like |
|
Definition
| countless individual particles orbiting Saturn independently like a tiny moon. They lie in Saturn's equatorial plane and are extremely thin |
|
|
Term
| Why is there an asteroid belt? |
|
Definition
| It was the only place where rocky planetismals could survive for billions of years..they did not accrete into a planet |
|
|
Term
|
Definition
| Meteors that survive the plunge through our atmosphere and hit the ground. They are usually covered with a dark pitted crust, have a unusually high metal content, and contain iridium |
|
|
Term
|
Definition
| Simple mixtures of rock and metal. They can be nearly 4.6 million years old and are unchanged since their birth |
|
|
Term
|
Definition
| Younger then primitive meteorites, they could have came from the core of a shattered asteroid or were blasted off the surface of an asteroid by an impact |
|
|
Term
|
Definition
| orbits the sun every 76 years |
|
|
Term
| When do comets grow tails? |
|
Definition
| when they entire the inner solar system and are heated by the warmth of the sun |
|
|
Term
|
Definition
| gas escaping from the coma and extends directly outward from the Sun |
|
|
Term
|
Definition
| dust sized particles escaping from the coma, generally points away from the sun but has a slight curve back in the direction it came from |
|
|
Term
|
Definition
| A comet ejects small particles that follow it around in its orbit and the dust rains down on our planet whenever we cross a comet's orbit |
|
|
Term
|
Definition
| more distant, contains comets that once orbited among the Jovian planets |
|
|
Term
|
Definition
| they orbit in the region in which they formed, just beyond Neptune's orbit |
|
|
Term
| When did the sun begin to shine? |
|
Definition
| about 4.5 billion years ago when gravitational contraction made its core hot enough to sustain nuclear fusion |
|
|
Term
| What is the Sun's luminosity? |
|
Definition
|
|
Term
| What is the Sun's core temperature? |
|
Definition
|
|
Term
|
Definition
| the lowest layer of the atmosphere and the visible surface of the Sun. Temperature= 6000 K, this is where you'll find sunspots |
|
|
Term
|
Definition
| The process of splitting an atomic nucleus. Our power plants do this by splitting large nuclei into small ones to generate energy |
|
|
Term
| What is the source of all the energy the Sun releases into space? |
|
Definition
|
|
Term
| How does the energy from fusion get out of the Sun? |
|
Definition
| Randomly bouncing photons carry energy through the deepest layers of the Sun. Convection carries energy through the upper layers to the surface |
|
|
Term
|
Definition
| Particles that rarely interact with anything at all, and can pass through almost anything. They are a direct way to measure nuclear fusion in the Sun |
|
|
Term
| Why do sunspots appear dark in pictures? |
|
Definition
| They are less bright because they are cooler- about 4000k instead of the 5800k surrounding them |
|
|
Term
|
Definition
| Short lived, dramatic storms on the sun that send bursts of X rays and fast moving charged particles out into space. |
|
|
Term
|
Definition
| in which the average number of sunspots on the Sun rises and falls in approximately 11 years. Solar prominences, solar flares, and coronal mass ejections follow this cycle as well. |
|
|
Term
| How long does the Sun's complete magnetic cycle take? |
|
Definition
|
|
Term
| What does apparent brightness depend on? |
|
Definition
| Luminosity and the distance from Earth |
|
|
Term
| Inverse square law for light |
|
Definition
| apparent brightness = luminosity / 4pi X distance^2 |
|
|
Term
| What are the units for apparent brightness? |
|
Definition
|
|
Term
|
Definition
| the small annual shifts in a star's apparent position caused by Earth's motion around the Sun. |
|
|
Term
| More distant stars have ____ parallax angles |
|
Definition
|
|
Term
|
Definition
| how bright different stars appear in the sky. |
|
|
Term
| A large apparent magnitude means a ____ apparent brightness |
|
Definition
|
|
Term
| A star of magnitude 4 is ____ than a star of magnitude 1 |
|
Definition
|
|
Term
|
Definition
| O has the highest temperature and smallest wavelength |
|
|
Term
| How do we measure stellar masses? |
|
Definition
| Newton's version of Kepler's 3rd- binary star systems where two stars continually orbit one another |
|
|
Term
| Hertzsprung-Russell diagram |
|
Definition
| plots the surface temperatures of stars (horizontal axis that increases going left) against their luminosities (vertical axis, increasing as you go up) |
|
|
Term
|
Definition
| upper right- very large and very bright |
|
|
Term
|
Definition
| lower left- small and appear white because of their high temperatures |
|
|
Term
| Lifetimes on the main sequence |
|
Definition
| Higher mass stars live shorter lives because they exhaust their nuclear fuel more quickly |
|
|
Term
| Stellar masses _____ downward the main sequence |
|
Definition
|
|
Term
| Two factors of star clusters: |
|
Definition
1) they all lie about the same distance from earth.
2) they formed at about the same time |
|
|
Term
|
Definition
| modest size, young stars found in the disk of the galaxy |
|
|
Term
|
Definition
| Found in the halo, oldest stars, densely packed |
|
|
Term
|
Definition
| They are born in cold, relatively desne clouds. As a cloud fragment collapses under gravity, a rapidly rotating protostar surrounded by a spinning disk of gas in which planets may form. The protostar may also fire jets of matter outward along its poles |
|
|
Term
| Why do water and oil separate? |
|
Definition
| Water is denser then oil, so oil floats on water |
|
|
Term
| What is necessary for differentiation to occur on a planet? |
|
Definition
| It must be a mix of materials of different density and material inside must be able to flow |
|
|
Term
|
Definition
| protects us from charged particles from the Sun. Can create aurora- Northern Lights |
|
|
Term
| If the planet core is cold, do you expect it to have magnetic fields? |
|
Definition
| No. Planetary magnetic fields are generated by moving charges around, and if the core is cold, nothing is moving |
|
|
Term
| What is the main reason Venus is hotter than Earth? |
|
Definition
| The greenhouse effect is much stronger on Venus than Earth |
|
|
Term
| Jupiter does not have a large metal core like Earth. How can it have a magnetic field? |
|
Definition
| It has metallic hydrogen inside, which circulates and makes a magnetic field |
|
|
Term
| How does Io get heated by Jupiter? |
|
Definition
| Jupiter pulls harder on one side than the other |
|
|
Term
| Why are there very few asteroids beyond Jupiter's orbit? |
|
Definition
| Ice could form in the outer solar system (comets) |
|
|
Term
| What is the temperature of the Sun's corona? |
|
Definition
|
|
Term
| What is the sun's structure from inside out? |
|
Definition
| Core, radiation zone, convection zone, photosphere, chromosphere, corona |
|
|
Term
| What would happen inside the Sun if a slight rise in core temperature led to a rapid rise in fusion energy? |
|
Definition
| The core would expand and cool |
|
|
Term
| These 2 stars have the same luminosity- which one appears brighter? |
|
Definition
|
|
Term
| How would the apparent brightness of Alpha Centauri change if it were 3 times further away? |
|
Definition
| It would be only 1/9 as bright |
|
|
Term
| Hotter objects emit ___ light per unit area at all frequencies |
|
Definition
|
|
Term
| Hotter objects emit photons with a ___ average energy |
|
Definition
|
|
Term
| What is the Sun's life expectancy? |
|
Definition
|
|
