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Exploring the Universe PH109, Summer 97, TEST #4
NAME______________________________________
Please indicate the best answer to the following questions on the answer sheet provided. Each question is
worth 2 points unless noted otherwise.
1. The most accurate way to determine distances to nearby stars is
a) assume they are all the same distance away and use 1/d2
b) determine their color
c) measure their Doppler shift
d) measure their parallax
2. About how big is a parsec
a) the mean distance from the Earth to the Sun
b) the distance to the closest star
c) 3.26 light years
d) the size of the Earth’s orbit
3. The direction in the sky that our solar system is moving toward is called the
a) Apex
b) Solar Peak
c) Solar asymptote
d) stellar destination
4. Which is brighter, a star with a magnitude of
a) 1
b) 2
5. About how many magnitudes of brightness can a human with good eyesight detect
a) 1
b) 6
c) 10
d) 100
6. Which kind of stars are most common in our galaxy
a) big and bright
b) small and dim
7. In the stellar spectra classification scheme OBAFGKM, which type is the coolest
a) O
b) A
c) G
d) M
8. What stellar spectral class is our Sun
a) O
b) A
c) G
d) M
9. The source of energy for our sun is
a) Fusion
b) Fission
c) Gravitational
d) Chemical
10. The reason nuclear reactions produce energy is
a) atoms combine with oxygen to form new compounds
b) matter is being attracted to the Sun by gravity and releases its energy
c) part of the mater in the atoms is converted into energy
d) tidal forces from the planets distort the Sun
11. About how long does it take energy produced in the core of the Sun the reach the surface
a) 1 second
b) 1 year
c) 1.3 million years
d) 170 thousand years
12. The part of the Sun that we “see” is called the
a) sunspot
b) chromosphere
c) photosphere
d) penumbra
13. Films of matter erupting off the surface of the Sun show streams of material following curved paths
because
a) the Sun is curved
b) mater follows magnetic field lines
c) the Sun rotates
d) the Solar wind is a whirlpool
14. The Solar wind is
a) a stream of particles emitted by the Sun
b) the result of a low pressure cell on the Sun
c) caused by Solar heating of the Earth’s surface
d) what blows the sunspots around
15. The Sunspot cycle is
a) a new bicycle invented by the British
b) about 11 years long
c) the rotation rate of sunspots
d) time it takes sunspots to reach the Earth
16. The closest star formation region which can also be seen with the unaided eye
a) Orion nebula
b) ring nebula
c) globular cluster
d) Cyngus Cluster
17. Which wavelength would you choose to study star formation
a) infrared
b) visible
c) gamma ray
d) ultra violet
18. The reason the Solar system does not have a lot of dust and gas between the planets is
a) the solar wind blew the dust and gas out of the Solar system
b) the planets accreted all the gas and dust
c) the early Solar system was made up only of Hydrogen and Helium
d) the Sun burns them up
19. All the planets outside our Solar system have been detected by
a) Hubble Space Telescope
b) Radar
c) gravitation perturbations of spacecraft
d) Doppler effects in stellar spectra
20. Why do stars evolve
a) Gravity eventually wears out
b) they use up their fuel
c) stars try to merge with other stars thus reforming the star formation region
d) the universe is expanding
21. What classification do we give a star where the proton-proton cycle prevents the outer layers of the star
from collapsing in on itself
a) main sequence
b) white dwarf
c) neutron star
d) black hole
22. What classification do we give a star where degenerate electrons prevent the outer layers of the star
from collapsing in on itself
a) main sequence
b) white dwarf
c) neutron star
d) black hole
23. What classification do we give a star where degenerate neutrons prevent the outer layers of the star
from collapsing in on itself
a) main sequence
b) white dwarf
c) neutron star
d) black hole
24. What classification do we give a star where nothing can prevent the outer layers of the star from
collapsing in on itself
a) main sequence
b) white dwarf
c) neutron star
d) black hole
25. Which spectral class of star is larger
a) O
b) F
c) G
d) M
26. What is the Chandrasekhar limit
a) the maximum number of stars that a Galaxy can support
b) the maximum number of super novae a galaxy can have
c) the maximum number of sunspots the Sun can support
d) the maximum mass a star can have for electrons to hold it up
27. A Pulsar is a
a) rapidly rotating neutron star
b) rapidly pulsating whit dwarf star
c) a rapidly moving main sequence star
d) a rapidly evolving black hole
28. Black holes
a) created by science fiction writers
b) the result of stars too massive for neutrons to support them
c) condensed molecular clouds before star formation takes place
d) small dark spot seen on the surface of the Sun
29. It is unlikely that astronauts will ever pass through black holes because
a) they do not really exist
b) they are too small to hold a person
c) they cannot be found because they are black and cannot be seen
d) tidal forces would rip them apart
30. What kind of Galaxy do we live in
a) Globular
b) Spiral
c) Elliptical
d) Irregular
31. What is the name of our Galaxy
a) Milky Way
b) Andromeda
c) Orion
d) Cygnus
32. About how long will our Sun be on the main sequence
a) 1 billion years
b) 10 billion years
c) 10 million years
d) 100 million years
33. What astronomer proved that some of the nebulae cataloged by Messier where in fact large external
galaxies separate from our galaxy
a) Einstein
b) Copernicus
c) Hawking
d) Hubble
34. In the simulation we saw in class, what was the result of six galaxies interacting in a cluster
a) they all collapsed into one large galaxy
b) they were all destroyed
c) they were propelled out of the cluster
d) they formed a chain of galaxies
35. The relationship which equates distance with redshift velocity is called
a) Hubble’s Law
b) Law of Redshifts
c) Einstein’s Law
d) Doppler’s Law
36. Astronomers are beginning to believe that what lies at the center of most galaxies
a) star formation regions
b) very compact globular clusters
c) clusters of neutron stars
d) black hole
37. Einstein’s ring is
a) a planetary nebula
b) when the image of one galaxy gravitationally distorts the image of another
c) the effect that people living on the surface of a “balloon” can look all the way around forming
a ring
d) a treasured heirloom passed from astronomer to astronomer
38. What is the most common type of galaxy in the universe
a) Spiral
b) Elliptical
c) Irregular
d) Confused
39. What are the two satellite galaxies of our galaxy called
a) “A” and “B” galaxies
b) Alpha and Beta galaxies
c) large and small Magellanic clouds
d) large and small Einstein condensations
40. Why can we not use parallax to measure the distances to galaxies
a) they are too far away
b) they are too faint
c) they are too large
d) there are too many of them
41. (10 points) Why to astronomer consider clusters of stars so important
42. (10 points) Describe the evolutionary process our Sun will go through starting with the Sun on the
main sequence and concluding with its final state.