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31 Cards in this Set
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Star Casper exhibits a parallel angle of 1/2 arcsecond. Star Cutter exhibits a parallax angle of 1/8 arcsecond. Which star is further from the Earth? Casper? Cutter? Do they have the same distance? Or there is insufficient information to say? |
Cutter because if the numerator are the same (in this case, they are both 1), then the denominator that has the larger denominator number means that it is further from the Earth, in which case is Cutter because it is 1/8 arcsecond. The smaller the denominator number, the closer distance it is, and the denominator that is larger, means it is the smaller size, so since 1/8 is smaller than 1/2, that means Cutter, with its smaller parallax angle, is further out. A star with a greater parallax angle, aka a smaller denominator, is closer to the Earth. |
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A light year is a unit of what? Angle? Speed? Distance? Or time? |
A light year is a unit of distance |
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Which object could you determine the distance to use the Tully-Fisher method (otherwise known as a standard candle)? A planet? A nearby star? A distant star? Or a nearby galaxy? |
A nearby galaxy because astronomers call a very bright object we know the absolute magnitude from, a standard candle. |
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Which method could you use to determine the distance to a distant star within our galaxy? Parallax? Standard candles aka the Tully-Fisher method? Spectroscopic Parallax? Or radar? |
Spectroscopic Parallax because radar is for very close objects, parallax is only good to about 1000 parsecs, the Tully-Fisher method measures objects further out from our own galaxy, which then leaves spectroscopic parallax which we can use to determine the distance to a distant star since it would be further out than 1000 parsecs, but that are still within our own galaxy. |
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Suppose that a star is further than 10 parsecs away. What is a possible set of apparent magnitude and absolute magnitudes for this star? apparent m = 1 and absolute M = 1? apparent m = negative 1 and absolute M = 1? apparent m = 1 and absolute M = negative 1? Or apparent m = negative 1 and absolute M = negative 1? |
apparent m = 1 and absolute M = negative 1, because the bigger the apparent number, the dimmer the star, and if the star appears dimmer than it would be if it were 10 parsecs away, then it must be farther than 10 parsecs. If the apparent magnitude is greater than the absolute magnitude, as 1 is a greater number than negative 1, then it must be further than 10 parsecs. |
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A star has an apparent magnitude of 4.3 and an absolute magnitude of 4.3. How far is this star from Earth? Closer than 10 parsecs? Exact at 10 parsecs? Or further than 10 parsecs? |
Exactly 10 parsecs |
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Imagine that you simultaneously receive two satellite images of two people that live on planets orbiting two different stars. Each image shows the people at their 21st birthday parties. Consider the following possible interpretations that could be made from your observations. Which do you think is the most plausible interpretation? Both people are the same age but at different distances from you? Both people are different ages but at the same distance from you? The person that is closer to you is older? Or the person that is further from you is older? |
The person that is further from you is older. Because it took longer for the image to get to you. |
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A remote satellite in orbit very close to the Sum detects a solar flare erupting on the Sun's surface at 10:00 AM, as measured by the satellite's clock. Your clock here on Earth is exactly synchronized with the satellite clock. The Sun is located 8 light minutes away from Earth. What time will it be when you observe the energy from the solar flare here on Earth? 9:52 AM? 10:08 AM? Or 10:00 AM? |
10:08 AM because 8 minutes is how long it takes light to reach the Earth from the Sum. |
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A drawing shows Star A, Star B, and Earth all in a line. Star B is 50,000 light years from Star A, while Earth is 80,000 light years from Star A. When Star A appears 90,000 years old to an observer orbiting Star B, how old would Star A appear to an observer on Earth? 30,000 years old? 50,000 years old? 60,000 years old? 90,000 years old? Or 120,000 years old? |
60,000 years old because we already know there's a 30,000 year difference from what we were previously told due to 80,000 minus 50,000 |
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When an observer on Earth can first see Star A. , how old would Star A appear to an observer orbiting Star B? 30,000 years old? 50,000 years old? 60,000 years old? 90,000 years old? Or 120,000 years old? |
30,000 years old because once again 80,000 from 50,000 is 30,000 |
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If there is a picture of the Milky Way galaxy, and a white circle is drawn halfway from the center of it, approximately how far in light years from the center ofthe Milky Way galaxy would that represent? 1000 light years? 10,000 light years? 25,000 light years? 50,000 light years? Or 100,000 light years? |
25,000 light years because the total diameter of the Milky Way galaxy is 100,000 light years, so half of that would be 50,000 and half of that half would be 25,000 |
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About how large would the diameter of that white circle be if it were drawn at about 3 millimeters and the Milky Way galaxy was drawn at about an inch in diameter? 1000 light years? 10,000 light years? 25,000 light years? 50,000 light years? Or 120,000 light years? |
10,000 light years because there's about 25 millimeters in an inch and the Milky Way galaxy is 100,000 light years across, so that circle, if 3 millimeters in width, would then be 1/8th the distance of that inch, therefore being close to 10,000 light years in equivalence. |
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Galaxy Gamma has a diameter of 25,000 light years. How many Galaxy Gammas could fit across the Milky Way galaxy? Less than one? 2? 4? 10? Or 25? |
4. Because the Milky Way galaxy is 100,000 light years across |
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In which galaxy would you expect to only find Red Stars? A spiral galaxy, an elliptical galaxy? Both? Or neither? |
An elliptical galaxy |
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In which galaxy would you expect to find a lot of gas and dust? A spiral galaxy? An elliptical galaxy? Both? Or neither? |
A Spiral galaxy |
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Which galaxy is closely like our own Milky Way galaxy? A spiral? An elliptical? Both? Or neither? |
Spiral galaxy |
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Which galaxy is an elliptical galaxy? One with arms? One that's a roundish circle? Both? Or neither? |
Roundish circle |
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What kind of graph would show what the Milky Way galaxy's rotational curve would be if there were no dark matter? One who's orbital speed moved upward in a straight diagonal line to its distance? One that rises upward at an angle until it reaches its bulge point then tapers off to a straight line? One that curves and slopes downward to the right? Or one that curves upwards to the right? |
One that curves downward to the right |
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What kind of graph represents what the actual Milky Way galaxy's rotational curve looks like? A diagonal line moving upwards to the right? A line moving at a slant to the right till it reaches its bulge point then tapers off to a steady straight line? A downward rotational curve to the right? Or an upward rotational curve to the right? |
A line moving at a slant to the right till it reaches its bulge point then tapers off to a steady straight line. |
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The Sun orbits the center of the Milky Way galaxy at a rate about 200 kilometers per second. Imagine a star that is 40,000 light years away from the center. How fast would this star orbit? Slower that 200 kilometers per second? About 200 kilometers per second? Or faster than 200 kilometers per second? |
About 200 kilometers per second because the Sun is about 25,000 light years from the center of the Milky Way galaxy, so the difference between 25,000 to 40,000 wouldn't change speed difference all that much since the total diameter of the Milky Way galaxy is 100,000 light years across |
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On a picture of a star exhibiting parallax using a scale bar of zero to twenty in arcseconds, with its starting point being at 12 arcseconds on January 1st, and it's end point of parallax being at 16 arcseconds on July 1st, what is the angular separation of this star between those months? |
4 arcseconds |
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What is the parallax angle of this star if it's angular separation is 4 arcseconds? |
2 arcseconds. (Parallax angle is half of the angular separation) |
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What is the distance of this star if it's parallax angle is 2 arcseconds? |
1/2 parsec. (Distance is half of the parallax angle) |
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Consider the following three stars that formed exactly the same time today but at different locations in the universe....Cosmo Star is an O spectral class star with a main sequence lifetime of 3 million years. It's life will eventually end as a super nova type 2 and become a black hole. Cosmo Star is located in a galaxy 10 billion light years from Earth. Ollie Star, is a, K spectral class star with a main sequence lifetime of 12 billion years. It's life will eventually end as a slowly cooling white dwarf... Ollie Star is located in the Milky Way at a distance of 10,000 light years from Earth... Sullivan Star, is an F spectral class star with a main sequence lifetime of 5 billion years. It's life will eventually end in a super nova type 1 that will completely destroy Sullivan Star. Sullivan Star is located in a galaxy 6 billion light years from Earth.
Rank the stars in terms of total lifetime on the main sequence, from shortest to longest. |
Cosmo, Sullivan, Ollie because the hotter it is the shorter it lives and the hotness scale goes from O.B.A.F.G.K.M. from hottest to coolest. |
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Rank the stars in terms of which star observers on the Earth will see be born first to which star observers on the Earth will see be born last. |
Ollie, Sullivan, Cosmo because Ollie is only 10,000 light years away, while Sullivan comes in at second at 6 billion light years away, while Cosmo comes in at third at being 10 billion light years away. The closer the star, the brighter its apparent magnitude to us the easier we can see it. |
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Rank the stars in terms of which star observers on the Earth will see die first to which star observers on the Earth will see die last. |
Cosmo, Sullivan, Ollie. The complete opposite to which stars we would see be born first. |
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How long will it be until observers on the Earth see Sullivan Star be born? How long will it be until observers on the Earth see Sullivan Star die? |
6 billion years for observers to see Sullivan Star be born and 11 billion years for observers to see Sullivan Star die because we were told it will live for 5 billion years, and we were also told it is 6 billion light years away from the Earth.... therefore, since it's 6 billion light years away, we would see it be born in 6 billion years, and since it will live for 5 billion years, we will see it die in 11 billion years since 6 plus 5 equals 11. |
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Rank the stars from closest to the Earth to furthest |
Ollie, Sullivan, Cosmo because Ollie is 10,000 light years away, Sullivan is 6 billion light years away, and Cosmo is 10 billion light years away. |
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Rank the following objects in terms of size from smallest to largest: A. Jupiter. B. Globular cluster. C. Spiral galaxy. D. Neutron star. E. White Dwarf. F. Black Hole. G. Galaxy Cluster |
F. Black Hole. D. Neutron Star. E. White Dwarf. A. Jupiter. B. Globular cluster. C. Spiral galaxy. G. Galaxy cluster. |
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The spiral arms of a galaxy are blue in color. Why? |
This is where star formation is happening, so you have young, short lived very bright stars which are blue. |
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Scientist believe that Dark Matter accounts for most of the matter in our galaxy. What is Dark Matter and Why do scientists believe this? |
Dark Matter is matter That you can't see. It does not reflect, absorb, or emit light. Scientists believe this because it's needed to explain the galaxies observed rotational curve. |
