BUCKNELL UNIVERSITY

Astronomy 101- Quiz #4 Solutions

 
    1. A neutron star is so dense that
    1. All neutrons are crushed into quarks
    2. One cubic inch has a mass equal to that of earth
    3. The distance between adjacent neutrons is 10-15 meters
    4. The temperature in its center is larger than trillion degrees.

 
 
    1. The continuous X-ray emission from the poles of a rotating neutron star comes from a much larger area of the neutron star poles than the area from which the visible light comes. The emission may therefore be seen as
    1. Flashes of X-rays with ¼ the frequency of the flashes in the visible range
    2. Flashes of X-rays with twice the frequency of the flashes in the visible range
    3. Flashes of X-rays with 2/3 the frequency of the flashes in the visible range
    4. Flashes of X-rays with ½ the frequency of the flashes in the visible range.
    1. According to the equivalence principle light on earth is deflected by earth’s gravity. The reason that this effect is not easily observable is because
    1. The gravity on earth is larger than that near black holes
    2. The earth is not as compacted as black holes
    3. The earth never had fusion in its core
    4. The earth is too far from the center of the galaxy.
    1. The Chandrasekar limit for neutron stars is due to the fact that
    1. the quantum pressure cannot hold against gravity if the mass larger than a couple of solar masses
    2. the rotational speed of a neutron star may be so large that chunks of the neutron star fly off its surface
    3. magnetic field on the star may be so large the south magnetic pole will pull the south magnetic pole and collapse the star
    4. fusion processes in that star take less than one million years to conclude.
 
    1. When a faraway star is almost behind our sun the light from that star may
    1. be shifted towards the blue part of the spectrum
    2. be deflected by the sun’s gravity
    3. reverse its course and go back to the star
    4. turn into matter – anti matter pairs.