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USA Astronomy Test Final
USA Astronomy Test Final
162
Astronomy
Undergraduate 1
11/06/2012

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Cards

Term
A small (but expensive) apochromatic refrecting telescope has an objective that is 100mm in diameter and with a 600mm focal length. It is used with an eyepiece that has a 20 mm focal length. What is its magnification?
Definition
30X
Term
Telescope A has an objective with a diameter of 6 inches and telescope B has an objective with a diameter of 2 inches. Which of the following statements is ALWAYS true?
Definition
A has higher light gathering power than B
Term
The ability of a telescope to distinguish two nearby objects is called the telescope's
Definition
resolving power
Term
The "objective" of a telescope is
Definition
the main lens or mirror of a telescope, used to gather light
Term
The main reason that most professional research telescopes are reflectors is that
Definition
large mirrors are easier to build than large lenses
Term
What is the primary purpose of an astronomical telescope?
Definition
To collect a lot of light and bring it into focus
Term
The tendency of a wave to bend as it passes from one transparent medium to another is called
Definition
refraction
Term
The resolution of a telescope is determined by
Definition
the size of the telescope's objective
Term
What intrinsic property of Venus makes it very reflective of light?
Definition
It is completely covered by clouds
Term
Which of the following is true about the planetary feature known as Olympus Mons?
Definition
It is a volcanic peak on Mars nearly as big across as Texas
Term
The four largest moons of Jupiter were first discovered by which of the following scientists?
Definition
Galileo Galilei
Term
Jupiters' moon Europa might possibly harbor life because it has which of the following conditions?
Definition
A liquid water subsurface layer
Term
Roche's limit refers to that distance from a planet where
Definition
tidal forces will rip a moon apart
Term
What is the feature known as the "Great Dark Spot" of Neptune?
Definition
It was an apparent temporary feature about the size of Earth, similar to the Great Red Spot of Jupiter, but disappeared within a few years.
Term
What substance is responsible for the colors of Neptune and Uranus?
Definition
Methane
Term
Venus has a feature named Aphrodite Terra. What is this feature?
Definition
a major highland area
Term
The American whose observations of "canals" sparked debate of life on Mars was
Definition
Percival Lowell
Term
Io is a moon of Jupiter and has many active volcanos. These volcanos and Io itself have an orangish color because
Definition
Io is rich in Sulfur
Term
Valalla is located on Jupiter;s moon, Callisto. Valhalla is
Definition
an impact basin
Term
The F ring on Saturn is held together by
Definition
a set of shepherd moons just inside and outside the F ring
Term
Who discovered Uranus?
Definition
William Herschel
Term
When we look at Uranus we are seeing
Definition
the tops of clouds in its atmosphere
Term
One moon of Uranus has huge angular ridges because it was possibly broken apart when it was struck by meteors and then fell back together. That moon is
Definition
Miranda
Term
The large gap in the rings of Saturn is called
Definition
Cassini's division
Term
What is the name of Pluto's largest moon
Definition
Charon
Term
Valle Marineris is a huge ___ found on the planet ___.
Definition
canyon, Mars
Term
Which planet is the most massive planet?
Definition
Jupiter
Term
Which planet has its axis of rotation tilted 90 degrees, so that the poles sometimes point directly towards the Sun?
Definition
Uranus
Term
Which planet is the smallest in size?
Definition
Mercury
Term
What is the name of the fourth planet from the Sun?
Definition
Mars
Term
Which planet would float in water, if we could get a bathtub big enough?
Definition
Saturn
Term
Which of the following planets has the greatest density?
Definition
Mars
Term
Which palnet is closest to the Sun?
Definition
Mercury
Term
Why is Mars red?
Definition
The iron in the surface rocks have been oxidized over time
Term
Which planet did William Hershel discover?
Definition
Uranus
Term
Which planet has a moon named Triton?
Definition
Neptune
Term
What is the name of the sixth planet from the sun?
Definition
Saturn
Term
What is Cassini's Division?
Definition
A large gap in the rings of Saturn
Term
Back in the 60's a grade B science fiction movie was released titles "journey to the Seventh Planet." What is the name of the seventh planet that was visited in this forgettable classic?
Definition
Uranus
Term
Mercury's surface
Definition
is largely covered with craters
Term
Two stars of the same spectral class are plotted in the Hertzsprung-Russell diagram. Star A has a higher luminosity than Star B. This tells you that
Definition
star A is larger than star B
Term
Sunspots appear dark because they are
Definition
cooler than the surrounding photosphere
Term
The flash spectrum of a solar eclipse reveals the conditions within the Sun's
Definition
chromosphere
Term
From which layer of the solar atmosphere does the solar wind originate?
Definition
Corona
Term
The time between successive sunspot maxima is about
Definition
11 years
Term
A dedicated astronomer working at the Keck telescope in Hawaii has discovered a small cluster of five stars. He takes the spectrum of each star to determine their spectral class. Which has the highest surface temperature?
Definition
Class O
Term
All of the stars in the above mentioned cluster lie on the main sequence. Which star has the highest mass?
Definition
class O
Term
Which star in the cluster has the lowest lunmiosity?
Definition
class M
Term
Refer to the H-R diagram to the right. Which type of stars are in the region labeled AA?
Definition
White dwarfs
Term
Refer to the H-R diagram to the right. Which type of stars are in the region labeled BB?
Definition
Main Sequence
Term
Refer to the H-R diagram to the right. Which type of stars are in the region labeled CC?
Definition
Red Giants
Term
Refer to the H-R diagram to the right. Which type of stars are in the region labeled DD?
Definition
Supergiants
Term
What is Hydrostatic Equilibrium?
Definition
It is the balance between outward gas pressure and gravity in stars
Term
The radial velocity of a star can be determined from its
Definition
spectral line Doppler shift.
Term
The apparent magnitude of a star is determined with a photometer attached to a telescope. The distance to the star is determined by parallax. Using those two pieces of information, we can then determine the star's
Definition
absolute magnitude
Term
A star whose binary nature is revealed by its moving spectral lines is called
Definition
a spectroscopic binary
Term
Binary stars are particularly important for determining stellar
Definition
mass
Term
Binary stars discovered by means of their varying light intensity are called
Definition
eclipsing binary stars
Term
The outermost layer of the Sun's atmosphere is called the
Definition
corona
Term
An astronomer looks at the spectrum of a star and notices that the absorption lines in the star's spectrum are red shifted. The astronomer correctly concludes that
Definition
the star is moving away from Earth
Term
Which of the following quantities are plotted along the horizontal axis of an H-R diagram?
Definition
surface temperature or spectral class
Term
Which of the following quantities are plotted along the vertical axis of an H-R diagram?
Definition
luminosity or absolute magnitude
Term
If a star has an apparent magnitude of 4 and is 10 parsecs from Earth, what is its absolute magnitude?
Definition
4
Term
If a star has a parallax of 0.1 arc second, what is its distance?
Definition
10 parsecs
Term
The luminosity of a star depends upon the star's
Definition
surface area and temperature
Term
The spectral class of the Sun is G2 and that of the star Enif is K2. From this information we know with certainty that Enif is
Definition
cooler than the Sun
Term
Which of the following spectral-luminosity classes would correspond to a red main sequence star?
Definition
M3 V
Term
An astronomer working at the Kitt Peak Observatory in Arizona has discovered a nebula with a pleasing red color in photographs. Our astronomer reasons that his nebula
Definition
is an emission nebula
Term
Our hard-working Kitt Peak astronomer is still at it. He had found a nebula with a blue tint. So, he knows that
Definition
It is a reflection nebula with lots of dust in it
Term
One effect of the interstellar medium on star light is
Definition
interstellar reddening, in which blue light of the stars is selectively scattered
Term
An astronomer has determined that the star he is studying has a spectral class A3 and luminosity class V. If the star has no parallax, how can he determine the star's distance?
Definition
Using the H-R diagram and the method of spectral parallax
Term
If a star's size decreased, while it remained the same temperature, its position on the H-R diagram would move
Definition
down
Term
Star A and Star B both have an apparent magnitude of 4.0, but star A has an absolute magnitude of 1.0 and star B has an absolute magnitude of 7.0. Which statement below is correct?
Definition
Star A and Star B appear to have the same brightness, but actuall Star A is brighter than Star B.
Term
What physical property of a star does the spectral type measure?
Definition
temperature
Term
The overall dimming of starlight by interstellar matter is called
Definition
extinction
Term
When an electron in hydrogen changes its spin from the same to the opposite direction as the proton, it
Definition
emits a radio wave photon
Term
By what mechanism does solar energy reach the Sun's photosphere from the layer just underneath it?
Definition
convection
Term
In what layer of the Sun is most of the energy produced?
Definition
core
Term
In the proton proton cycle
Definition
4 protons are fused to form a heilum nucleus
Term
A by-product of fusion in the Sun is a neutrino which
Definition

(all of the above)

is almost massless

is neutral

almost never interacts with matter

can spontaneously change from one type of neutrino to a different type

Term
If we had a full moon last night, in what phase will the moon be two weeks later?
Definition
new moon
Term
Which of the following statments is a definition for an Astronomical Unit?
Definition
A unit of distance equal to the average distance between the Earth and the Sun
Term
You go outside and abserve that the north celestial pole is on your horizon. Using reasoning that would make Sherlock Holmes envious, you deduce that
Definition
you are standing on the Earth's equator
Term
Where was the Sun on the celestial sphere on the Autumnal Equinox?
Definition
At an intersection of the ecliptic and the Celestial Equator
Term
What happens when the Sun is on the Winter Solstice?
Definition
It is the first day of winter according to people in the northern hemisphere
Term
A full Moon must always set at approximately what time of day or night?
Definition
Sunrise
Term
A new Moon must always set at approximately what time of the day or night?
Definition
Sunset
Term
A light year is
Definition
the distance light travels in a year
Term
Which of the following stars is most likely to be the brightest star in the constellation Orion?
Definition
Betelgeuse (a, alpha Orionis)
Term
Kepler stated that the planets orbits are best described as
Definition
elliptical orbits about the Sun
Term
What is the ecliptic?
Definition
The apparant path of the Sun on the celestial sphere due to Earth's orbital motion
Term
If a star lies exactly on the north celestial pole, what is its declination?
Definition
90 degrees
Term
Copernicus believed that
Definition
the Sun is at the center of the universe with all planets orbiting the Sun
Term
An astronaut geta a mission to the International Space Station. While in orbit, the astronaut is three times as far from the center of the Earth than when he is on the ground. If the astronaut weighs 180 lbs on the ground, what does he weigh in orbit?
Definition
20 lbs
Term
During a solar eclipse
Definition

(All of the following are true)

 

prominences are visable during totality

the solar corona is visable during totality

the umbra of the Moon's shadow strikes the Earth

the moon is in its new phase

Term
What was the greatest contribution of Tycho Brahe to astronomy?
Definition
He amasses a large number of precise measurements of stellar and planetary positions in the sky
Term
Near the end of his life, Tycho hired what famous scientist as his assistant?
Definition
Johannes Kepler
Term
One of Kepler's three laws of planetary motion is that
Definition
the imaginary line between the Sun and a planet sweeps out equal areas in equal times
Term
A solar day is defined to be
Definition
the time it takes for the sun to make successive crossings of the lower half of the celestial meridian
Term
The zenith is
Definition
the point on the celestial sphere directly over your head
Term
If the North Star os 60 degrees above the horizon, what is your latitude?
Definition
60 degrees
Term
On the first day of spring what is the Sun's position on the celestial sphere?
Definition
It is on the vernal equinox
Term
During a lunar eclipse
Definition
The Moon moves into the Earth's shadow
Term
The point on the celestial sphere directly above Earth's north pole is called
Definition
north celestial pole
Term
Ptolemy's system of epicycles was used to explain the
Definition
retrograde motion of the planets
Term
An eclipse (lunar or solar) can NEVER occur when
Definition
the moon's phase is first quarter
Term
As you watch the sun set, you notice the moon directly overhead. What phase is the moon in?
Definition
first quarter
Term
A man who weighs 240 lbs, desperately wants to be an astronaut. Told he exceeds the weight limits, he goes on Dr. Skinner's "No gain, No Pain" diet. His body mass decreases by a factor of 2/3. What does the man weigh at the end of his diet?
Definition
1/3 *240=80 lbs

*answer key wrong 160 lbs (poorly worded ? )
Term
What was one of Copernicus's contributions to astronomy?
Definition
He said that the Earth is not at the center of the universe
Term
The Local Celestial Meridian is
Definition
the line on the celestial sphere running from the North Celestial Pole, through your zenith, to the South Celestial Pole, through your nadir, and back to the North Celestial Pole.
Term
Which of the following is Kepler's third law of planetary motion?
Definition
The square of the orbital period of a planet (in years) is proportional to the cube average orbital distance from the sun (in A.U.)
Term
Solar time is
Definition
hour angle of the Sun with the upper half of the local celestial meridian
Term
The lower the frequency of electromagnetic radiation
Definition

the longer its wavelength

 

*also correct was the redder it will be (visible light)

Term
The factor which distinguishes one element from another is
Definition
the number of protons in the nucleus of the atom of the element
Term
According to Kirchoff's laws, what type of substance would emit an emission spectrum?
Definition
a low density gas
Term
As a blackbody radiator increases in temperature the radiation it emits
Definition
will decrease in wavelength and incease in intensity (get brighter)
Term
Which of the following has one proton and zero neutrons in its nucleus?
Definition
Hydrogen
Term
If you view a hot star through a cool cloud of gas, what sort of spectrum are you likely to see?
Definition
continuous
Term
The frequency of an electromagnetic wave is defined to be
Definition
the number of waves passing by in one second
Term
Isotopes of an element
Definition
have same number of protons, but different numbers of neutron in their nuclei
Term
Which of the following statements does NOT apply to the structure of atoms?
Definition
protons and electrons make up the nucleus
Term
What type of spectrum would be emitted by a hot, luminous solid?
Definition
Continuous
Term
The wavelength of an electromagnetic wave is defined to be
Definition
distance from peak in the wave to the next peak
Term
A blackbody radiator produces what type of spectrum?
Definition
continuous
Term
A type II supernova is produced when
Definition
the iron core of a high mass star collapses
Term
A type I supernova is produced when
Definition
a white dwarf exceeds the Chandrasekhar limit
Term
At what stage in its life will our Sun become a black hole?
Definition
The Sun will never become a Black Hole
Term
The heaviest elements in the universe (such as gold, lead, and uranium) were probably created in
Definition
supernovae
Term
By what process are neutrinos formed in supernova?
Definition
forcing electrons into the nuclei of the atoms and changing the protons into neutrons (neutronization)
Term
A nova is always associated with
Definition
a white dwarf star in a close binary star system
Term
One of the causes of a nova is
Definition
mass falling from a red giant onto a white dwarf in double star system
Term
The main energy source of red giant stars is
Definition
helium fusion via the triple alpha process
Term
What characteristic of a star cluster is used to determine its age?
Definition
the main sequence turnoff point
Term
The H-R diagram below shows the path of a 1 solar-mass star as it evolves. What is important about the point labled E on the diagram?
Definition
The star is a red giant
Term
The H-R diagram below shows the path of a 1 solar-mass star as it evolves. What is important about the point labled D on the diagram?
Definition
The star is undergoing helium flash
Term
The H-R diagram below shows the path of a 1 solar-mass star as it evolves. What is important about the point labled A on the diagram?
Definition
The star is a protostar
Term
At what point on the H-R diagram above is the star forming a planetary nebula?
Definition
G
Term
It is believed that X-Ray bursters must occur in a binary star system. What are the two types of stars that must be present to make up such an object?
Definition
a red giant and a neutron star
Term
Clusters which are newly formed, i.e. young star clusters are
Definition
open (galactic) clusters
Term
Star clusters which are very crowded with stars and are very old are also
Definition
globular clusters
Term
Lighter elements are fused into elements more massive than iron in
Definition
a supernova
Term
The most massive element that can be formed by fusion along with a release of energy is
Definition
iron
Term
A planetary nebula is
Definition
an expanding shell of gas about a star
Term
Prior to reaching the main sequence, a protostar's energy comes from
Definition
gravity
Term
As a star evolves it passes along the "Hayashi track". What is happening to the star while on this track?
Definition
It is a protostar
Term
What is the meaning of the phrase "zero age main sequence" when applied to stars?
Definition
It is the left edge of the main sequence where stars begin their time fusing hydrogen into helium
Term
Mass from binary companion flowing onto the surface of a white dwarf star can cause the white dwarf to become a
Definition
nova
Term
A nova differs from a supernova in that the nova
Definition
is much less luminous
Term
Cepheid variables are important to astronomers because
Definition
thay are useful in determining distances.
Term
What is the helium flash?
Definition
the explosive beginning of helium fusion in the electron degenerate gas in the core of an old star
Term
What is the more important factor in determining how a star evolves?
Definition
mass
Term
A protostar is
Definition
A prestellar object that is hot, but not hot enough for fusion to occur
Term
What is the triple alpha process?
Definition
the process in which helium nuclei are fused to form carbon
Term
At some time in the future, the Sun will
Definition

All of the above are true

 

  • become a white dwarf
  • become a red giant
  • have a helium flash
Term
What supports a white dwarf from further collapse?
Definition
the "Pauli pressure" from electron degeneracy
Term
What is generally found at the center of a planetary nebula?
Definition
a white dwarf
Term
When a supergiant star forms an iron core, what next will happen to the star?
Definition
It will become a type II supernova
Term
A cloud fragment too small to form a star will become a
Definition
brown dwarf
Term
A newly formed protostar will radiate primarily at what wavelength
Definition
infrared
Term
A star will evolve "off the main sequence" when it uses up
Definition
most of the hydrogen in its core
Term
Compared to our Sun, a typical white dwarf is
Definition
about the same mass and a million times higher density
Term
In order of visual luminosity at the start, which has the highest luminosity?
Definition
Type I supernova
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