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euphoria0697
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Here's my astronomy homework for the week.
bold = my answer.
Any help is appreciated!
Question 1 Multiple Choice 5 points
The apparent brightness of stars in general tells us nothing about their distances. In order for the apparent brightness of a star to be a good indicator of its distance, all the stars would have to be:
at the same distance
the same composition
the same luminosity
by themselves instead of binary or double-star systems
Question 2 Multiple Choice 5 points
Whic if the following stars is a Cepheid variable?
Sirius
Betelgeuse
Rigel
Polaris
Question 3 Multiple Choice 5 points
Astronomers must often know the distance to a star before thay can fully understand its characteristics. Which of the following properties of a star typically requires a knowledge of distance before it can be determined?
its luminosity
its radial velocity
its temperature
its apparent brightness
Question 4 Multiple Choice 5 points
Which of the following will show the smallest parallax shift?
the Moon
the planet Jupiter
the Sun
the star 51 Pegasi, about 50 LY away
Question 5 Multiple Choice 5 points
You are observing a binary star system and obtain a series of spectra of the light from the two stars. In this spectrum, most of the absorption lines shift back and forth as expected from the Doppler effect. A few lines, however, do not shift at all, but remain at the same wavelength. How can we explain the behavior of the non-shiftnig lines?
there is a star in the system which is not moving at all: it is just sitting there
there is a planet orbiting the stars in the system
there are huge clouds of dust just behind this star system from our perspective
the lines come from interstellar matter between us and the star, not from the stars themselves
Question 6 Multiple Choice 5 points
An astronomer wants to observe a cloud of cold neutral (not ionized) hydrogen, far away from any stars. What would be an instrument that could help in this task?
a telescope in space, able to pick up x-rays from space
a radio telescope , tuned to a wavelength of about 21 cm
a large telescope observin visible light, but with a very sensitive detector attached
a neutrino detector, deep underground
Question 7 Multiple Choice 5 points
Astronomers have found large quantities of cold, neutral hydrogen gas in our galaxy. How is this gas distributed?
it is located only near stars, and not in the large empty spaces between them
it is found mostly in a flat layer extending throughout the disk of our galaxy
it is found in a spherical distribution about 100 LY in size, cenetered on the Sun
if is found only in the outer regions of the galaxy, where we are, and not in the central areas.
Question 8 Multiple Choice 5 points
Observations show that some gas in interstellar space has been heated to temperature of a million degrees or so. What mechanism do astronomers believe is reponsible for this heating?
Stars like the sun shine on the gas, heating it
Th eatoms in the gas collide, heating each other
new stars are forming in the regions of hot gas, heating it
exploding stars are responsible for heating the gas with the energy of their explosion.
Question 9 Multiple Choice 5 points
A star whose temperature is increasing but whose luminosity is roughly constant moves in what direction on the H-R diagram?
to the right
to the left
upwards
downwards
Question 10 Multiple Choice 5 points
Astronomers identify the "birth" of a real star (as opposed to the activities of a protostar) with what activity in the star?
when it starts to contract rapidly from a cloud of gas and dust
when it first becomes visible inside its dust cloud
when a wind is observed coming from its surface
when nuclear fusion reactions begin inside its core
Question 11 Multiple Choice 5 points
The big surprise about the first planet discovered around another (liing) star was that it
was smaller than Mercury or Pluto in our own solar system
orbited so close too its star it took only 4 days to go around
has a mass greater than that of most stars
had a spectrum which indicated it was made of elements we never find on Earth
Question 12 Multiple Choice 5 points
With the technique used to discover the first planets around other living stars, only some kinds of planets can be found. The kinds of planets we are able to find with this technique today are:
only terrestrial planets
only cold planets
only planets that have masses like Jupiter or Saturn
only planets with giant orbits (like Pluto or larger)
Question 13 Multiple Choice 5 points
Which of the following types of stars will spend the longest time (the greatest number of years) on the main sequence?
O
A
G
K
Question 14 Multiple Choice 5 points
How long a main sequence star remains on the main sequence in the H-R diagram depends most strongly on
its initial composition
the number of companion stars or planets orbiting it
its radial velocity
its mass
Question 15 Multiple Choice 5 points
When the outer layers of a star like the Sun expand, and it becomes a qiant, which way does it move on the H-R diagram?
toward the upper right
toward the upper left
toward the lower right
toward the lower left
Question 16 Multiple Choice 5 points
A star with a mass like the sun which will soon die is observed to be surrounded by a large amount of dust and gas - all material it has expelled in the late stages if uts life. if asrtonomers want to observe the radiation from such a giant star surrounded by its own debris, which of the following bands of the spectrum would be the best to use ot observe it?
gamma-rays
x-rays
unltraviolet
infrared
Question 17 Multiple Choice 5 points
The event in the life of a star that begins its expansion into a giant is
the core reaches a temperature of ten million degrees
as much as 90% of the star explodes violently
almost all the hydrogen in its core that was hot enough for fusion has been turned into helium the star's internal structure reaches equilibrium for the first time in its life
Question 18 Multiple Choice 5 points
A white dwarf, compared to a main sequence star with the same mass, would always be:
redder in color
smaller in diameter
the same size
younger in age
Question 19 Multiple Choice 5 points
A neutron star as as dence as
water
the center of the Earth
a white dwarf star
the nucleus of an atom
Question 20 Multiple Choice 5 points
Astronomers have concluded that pulsars are
rotating black holes
rotating neutron stars
rotating red giants
supernovae that are about to explode
bold = my answer.
Any help is appreciated!
Question 1 Multiple Choice 5 points
The apparent brightness of stars in general tells us nothing about their distances. In order for the apparent brightness of a star to be a good indicator of its distance, all the stars would have to be:
at the same distance
the same composition
the same luminosity
by themselves instead of binary or double-star systems
Question 2 Multiple Choice 5 points
Whic if the following stars is a Cepheid variable?
Sirius
Betelgeuse
Rigel
Polaris
Question 3 Multiple Choice 5 points
Astronomers must often know the distance to a star before thay can fully understand its characteristics. Which of the following properties of a star typically requires a knowledge of distance before it can be determined?
its luminosity
its radial velocity
its temperature
its apparent brightness
Question 4 Multiple Choice 5 points
Which of the following will show the smallest parallax shift?
the Moon
the planet Jupiter
the Sun
the star 51 Pegasi, about 50 LY away
Question 5 Multiple Choice 5 points
You are observing a binary star system and obtain a series of spectra of the light from the two stars. In this spectrum, most of the absorption lines shift back and forth as expected from the Doppler effect. A few lines, however, do not shift at all, but remain at the same wavelength. How can we explain the behavior of the non-shiftnig lines?
there is a star in the system which is not moving at all: it is just sitting there
there is a planet orbiting the stars in the system
there are huge clouds of dust just behind this star system from our perspective
the lines come from interstellar matter between us and the star, not from the stars themselves
Question 6 Multiple Choice 5 points
An astronomer wants to observe a cloud of cold neutral (not ionized) hydrogen, far away from any stars. What would be an instrument that could help in this task?
a telescope in space, able to pick up x-rays from space
a radio telescope , tuned to a wavelength of about 21 cm
a large telescope observin visible light, but with a very sensitive detector attached
a neutrino detector, deep underground
Question 7 Multiple Choice 5 points
Astronomers have found large quantities of cold, neutral hydrogen gas in our galaxy. How is this gas distributed?
it is located only near stars, and not in the large empty spaces between them
it is found mostly in a flat layer extending throughout the disk of our galaxy
it is found in a spherical distribution about 100 LY in size, cenetered on the Sun
if is found only in the outer regions of the galaxy, where we are, and not in the central areas.
Question 8 Multiple Choice 5 points
Observations show that some gas in interstellar space has been heated to temperature of a million degrees or so. What mechanism do astronomers believe is reponsible for this heating?
Stars like the sun shine on the gas, heating it
Th eatoms in the gas collide, heating each other
new stars are forming in the regions of hot gas, heating it
exploding stars are responsible for heating the gas with the energy of their explosion.
Question 9 Multiple Choice 5 points
A star whose temperature is increasing but whose luminosity is roughly constant moves in what direction on the H-R diagram?
to the right
to the left
upwards
downwards
Question 10 Multiple Choice 5 points
Astronomers identify the "birth" of a real star (as opposed to the activities of a protostar) with what activity in the star?
when it starts to contract rapidly from a cloud of gas and dust
when it first becomes visible inside its dust cloud
when a wind is observed coming from its surface
when nuclear fusion reactions begin inside its core
Question 11 Multiple Choice 5 points
The big surprise about the first planet discovered around another (liing) star was that it
was smaller than Mercury or Pluto in our own solar system
orbited so close too its star it took only 4 days to go around
has a mass greater than that of most stars
had a spectrum which indicated it was made of elements we never find on Earth
Question 12 Multiple Choice 5 points
With the technique used to discover the first planets around other living stars, only some kinds of planets can be found. The kinds of planets we are able to find with this technique today are:
only terrestrial planets
only cold planets
only planets that have masses like Jupiter or Saturn
only planets with giant orbits (like Pluto or larger)
Question 13 Multiple Choice 5 points
Which of the following types of stars will spend the longest time (the greatest number of years) on the main sequence?
O
A
G
K
Question 14 Multiple Choice 5 points
How long a main sequence star remains on the main sequence in the H-R diagram depends most strongly on
its initial composition
the number of companion stars or planets orbiting it
its radial velocity
its mass
Question 15 Multiple Choice 5 points
When the outer layers of a star like the Sun expand, and it becomes a qiant, which way does it move on the H-R diagram?
toward the upper right
toward the upper left
toward the lower right
toward the lower left
Question 16 Multiple Choice 5 points
A star with a mass like the sun which will soon die is observed to be surrounded by a large amount of dust and gas - all material it has expelled in the late stages if uts life. if asrtonomers want to observe the radiation from such a giant star surrounded by its own debris, which of the following bands of the spectrum would be the best to use ot observe it?
gamma-rays
x-rays
unltraviolet
infrared
Question 17 Multiple Choice 5 points
The event in the life of a star that begins its expansion into a giant is
the core reaches a temperature of ten million degrees
as much as 90% of the star explodes violently
almost all the hydrogen in its core that was hot enough for fusion has been turned into helium the star's internal structure reaches equilibrium for the first time in its life
Question 18 Multiple Choice 5 points
A white dwarf, compared to a main sequence star with the same mass, would always be:
redder in color
smaller in diameter
the same size
younger in age
Question 19 Multiple Choice 5 points
A neutron star as as dence as
water
the center of the Earth
a white dwarf star
the nucleus of an atom
Question 20 Multiple Choice 5 points
Astronomers have concluded that pulsars are
rotating black holes
rotating neutron stars
rotating red giants
supernovae that are about to explode