Test 5 – Flashcard Test Questions
Flashcard maker : Kael Dunlap
What is the upper limit of stars the unaided eye can discern on a moonless night in a rural area?
C. About 3,000
The diurnal rotation of the stars refers to the
A. Apparent rotation of the celestial sphere due to the rotation of the Earth
The North Star has very little apparent rotation in the night sky because
D. It lies directly in the Northern path of the projection of the Earth’s axis of spin
Which best describes the intrinsic motion of stars?
D. Their motion relative to all other bodies
Summer and Winter constellation are different because
D. The night sky faces in opposite direction in summer and winter
Polaris is always directly overhead
C. The north pole
In which city is Polaris highest in the sky?
A. Anchorage
The background stars of a lunar eclipse are those of constellations
C. Of the opposite season
The star nearest the Earth is
A. The sun
We do not see stars in the daytime because
E. Skylight overwhelms starlight
A star’s brightness tells us
D. How much energy a star produces
A star’s color tells us
A. Its surface temperature
Luminosity is
A. The total amount of light energy that star emits into space
What is the reference that astronomers use to denote the luminosity of stars?
D. The luminosity of the sun
Why does a star’s color corresponds to its temperature?
A. Higher temperature means more energetic light, which is seen as higher frequencies
Which star will emit the shortest wavelength of its peak frequency?
C. A blue star
Thermonuclear fusion occurs mainly in the
A. Cores of stars
The temperature of a star is evidenced by its
E. Color
On the H-R diagram our sun is a
C. Star of average luminosity and temperature
Giant stars are
C. Close to exhausting their supply of hydrogen
Which is greater, the gravitational attraction between a newborn baby and the Earth, or the gravitational attraction between the Earth and all the planets of the solar system?
D. The attraction between the baby and Earth
The event that changes a protostar to a full-fledged star is
C. Thermonuclear fusion
The longest living stars are those of
A. Low mass
The masses of stars are found by measurement of
B. Binaries
The H-R Diagram, an important tool of astronomers, relates stellar temperature to stellar
B. Brightness
A star’s size stabilizes when
D. Thermal pressure and gravitational attraction balance each other
What is the determining factor in the stages a star will progress through from birth to death
C. Its mass
What prevent stars greater than about 100 times the sun’s mass from existing
A. The rate of thermal expansion would overcome gravitational attraction leading to explosion
How is a larger star like an SUV, while a smaller star is like a hybrid vehicle?
A. The larger the star, the faster it burns fuel
What event will eventually move an average star off the main sequence of the H-R diagram?
D. Running out of hydrogen, causing gravitational influx, resulting in core temperature high enough to begin fusing helium
What is generally the range of a star’s hydrogen burning lifetime?
A. From a few million to 50 billion years
What do astronomers expect will be left at the center of our solar system once the sun has gone through all its life stages?
C. A planet size diamond
Because a white dwarf is no longer burning fuel, it is more accurately described as being a
C. Stellar remnant
Supernovae are one of the most extreme events in the know universe. They are caused by
B. The collapse of a super massive super giant star
After our sun burns its supply of hydrogen, it will become a
D. Red giant
A white dwarf is a former
B. Low-mass star
Which one of these elements is normally the remnant of a supernova?
C. Silver
The elements found on Earth have much to do with
A. Supernovae
A pulsar is likely a
A. Spinning neutron star
Most of the atoms in the universe are thought to be
A. Hydrogen
A black hole is
D. All of the above
A black hole has
C. About the same mass as the original star from which it formed
The event horizon of a black hole is
C. The surface below which no matter or energy can escape
What determine if a white star become a white dwarf, a neutron star, or a black hole
D. The principal factor is mass
A black hole is
C. The remains of a giant collapsed star
If the sun collapsed to become a black hole, the Earth’s gravitational attraction to it would be
A. No different
When a star collapsed to become a black hole, its mass
C. Remains unchanged
When a star collapses to half sized, the gravitational field at its surface
B. Quadruples
As more and more mass falls into a black hole, the radius of its photon sphere
A. Decreases
As a star undergoes collapse, its rate of rotation
B. Increases
One of Edwin Hubble’s discoveries is that the known universe is expanding. This means that
B. Most all observable galaxies are moving away from each other.
Galaxies are aggregations of stars, stellar dust, and gas. Their masses
A. Vary greatly from one galaxy to the next
Elliptical galaxies
D. All of the above
The milky way galaxy is
D. All of the above
An active galactic nucleus
B. Arises from the gigantic black hole at the center of gravity
Quasars are
D. Ancient, extremely high energy galaxies believed to have formed in the early universe
A super cluster is a
D. cluster of galactic clusters
The observable universe is
A. the minor portion of the universe we can observe
All of the stars we see at night with our unaided eyes are within
D. 10,000 light-years, which is a small portion of our galaxy
The Milky Way is
D. A spiral galaxy
Most of the stars in colliding galaxies
C. Do not make contact with one another
Compared to most stellar objects, quasars are more
D. All of these
Cosmology is the study of the overall structure and evolution of
D. The Universe
Relativity is the
B. Study of how space, energy, and mass are related to time
Edwin Hubble discovered that the farther away a galaxy is the
D. Faster it is receding from us
The big bang refers to the
B. point in time in which the know ( and perhaps knowable) Universe cam into being
The big bang
B. Marked the beginning of space and time
The redshift of a galaxy refers to the rate
C. At which is receding
The difference between light waves,approaching light waves receding is
A When approaching, light waves have their frequency; when receding their frequency is lower.
Cosmological redshift refers to
C. The expansion of space itself
How did Mr. Hubble calculate the age of the universe
D. By measuring the rate of expansion of the universe
According to calculations made by modern astronomers, the age of the universe is close to
B. 14 billion years
Cosmic background radiation refers to
D. Uniformly distributed residual radiation that resulted from the big bang
Astronomers who subscribe to the big bang theory believe the big bang occurred
C. both of these
Evidence for the big bang is
C. Both of these
The big bang is regarded as the expansion of
D. Space
We are actually looking into the past when we look at
C. Actually, both of these
Dark Matter is matter that
A. cannot be seen or felt, but can be measured through its gravitational effects.
Evidence for dark matter is exhibited by the
D. All of the above
Dark energy
D. All of the above
Dark energy bend the curvature of space time
A. in the opposite manner of gravity
The big rip refers to the
B. Accelerating influence of dark energy, causing all matter to become completely ripped apart
Eternal Inflation refers to
D. The possibility that our universe is only a patch of a greater universe and that the process of the universe spawning will continue forever.
What are the relative composition of the material from which stars form
C. About 74% hydrogen, about 24% helium, no more than 2% other materials
If a star collapses to tenth its size, gravitational at its surface increases by
D. One hundred
A starburst galaxy has this name because of its
D. High rate of star formation
The zeroth latitude is at
C. the equator
A line of equal longitude is called a
C. circle
The sun appears to travel daily in the sky
A. One degree in 4 min
Six months of darkness at the south pole begins with the sun is at
D. vernal equinox
The four seasons -spring, summer , fall and winter are caused by the suns changing its daily latitude over a long period of 1 year. The sun’s altitude changes becuase
D. of the combined effects of a and c- A the earth revolves eastward about the sun C the earths axis is tilted 23.5
The number of daylight hours at 40s is greatest during the month of
B. December
The longest daylight day for people in the southern hemisphere at latitudes greater than 30S occurs at the
C. winter solstice
The altitude of the north star polaris is appox
C. equal to the observers local longitude
The tropical year is shorter than the sidereal year because the earths
B. axis processes westward
The earths axis completes a precession ever
25,800 yrs
