Test 4
A Type II Supernova is... A) The detonation of a massive star. B) The outward surge that results in a planetary nebula C) The explosion that results when a white dwarf exceeds a mass of 1.44 solar masses. D) The explosion that results when hydrogen fusion is triggered at the center of an accretion disc
A
Apparent magnitude measures the brightness of a star as seen from _____, whereas absolute magnitude measures the brightness of a star as seem from _____. A) Earth / 10 pc B) 10 pc / Earth C) the naked eye / a telescope D) a telescope / the naked eye
A
Binary star systems are very important because they allow A) Measurement of star masses B) Measurement of the speed of stars C) More precise measurement of the distance of stars D) More precise measurement of the temperature of stars E) More precise measurement of the spectral type of stars
A
For what type of stars does observing the parallax angle work well for determining the distance? A) Stars that are relatively close to Earth. B) Stars that are very distant from Earth. C) Only main-sequence stars. D) All stars except for Red Dwarf stars
A
For what type of stars does observing the parallax angle work well for determining the distance? A) Stars that are relatively close to Earth. B) Stars that are very distant from Earth. C) Only main-sequence stars. D) All stars except for Red Dwarf stars.
A
In what type of binary system is there no transfer of mass between the stars? A) Detached B) Semi-detached C) Contact D) Eclipsing
A
In which binary system can we observe both the stars separately and follow their orbits around each other? A) Visual binary system B) Spectroscopic binary system C) Eclipsing binary system
A
The Sun's core is generating energy in the form of ________. A) Gamma rays B) Ultraviolet C) X-rays D) Visible E) Radio
A
The proton-proton chain is... A) The hydrogen fusion process that occurs in lightweight stars like our Sun. B) The hydrogen fusion process that occurs in massive stars. C) The helium fusion process that occurs in lightweight stars like our Sun. D) The helium fusion process that occurs in massive stars
A
The temperature at the Sun's core is about _____. A) 15,000,000 K B) 1,500,000 K C) 150,000 K D) 15,000 K
A
What determines the radius of a star? A) The radius of a star is determined by the point where the gravitational pressure and the radiation pressure are in hydrostatic equilibrium. B) The radius of a star is determined by the point where the gravitational pressure and the gas pressure are in hydrostatic equilibrium. C) The radius of a star is determined by the point where the photosphere is in thermal equilibrium with the interstellar medium. D) Only the mass determines a star's radius.
A
What is the driving force behind the Babcock (sunspot) Cycle? A) The fact that the Sun rotates faster at its equator than at its poles causes the magnetic field to be wrapped around the Sun and distort. B) The increase of solar flares and CMEs cause the increase in sunspot number. C) The Earth's magnetic field interacts with the Sun's magnetic field to create complexities in the Sun's magnetic field. D) Variations in the rate at which nuclear reactions happen in the Sun's core alter the number of sunspots on the surface of the Sun
A
What type of object will be formed by a stellar core whose mass is 0.93 solar masses? A) White dwarf B) Neutron star C) Brown Dwarf D) Black hole
A
Where on the HR-Diagram are supergiants found? A) along the top of the chart B) in the right-center portion of the chart C) in the bottom left corner of the chart D) along a diagonal line from the upper left to the lower right corners
A
Which of the following objects produces an emission spectrum? A) Bright nebula B) Absorption nebula C) Planetary nebula D) Dark nebula
A
Why will a star far more massive than our Sun die? A) Iron fusion in the core absorbs energy and causes the star to collapse. B) The radiaion pressure from He-fusion is stronger than the gravitational pressure and forces the top layers of the star outward. C) The mass of the core of the star exceeds 1.44 solar masses. D) The star just runs out of fuel
A
A __________ happens when a white dwarf in a binary system accumulates more mass than Chandrasekhar limit. A) Nova B) Type Ia supernova C) Type II supernova D) Pulsar E) None of the above
B
A main-sequence star is any star that _____. A) Has the same mass as our Sun B) Is fusing hydrogen in its core C) Is fusing helium in its core D) Is a luminosity class Ia
B
Absolute magnitude measures the brightness of a star as seen from _____, whereas apparent magnitude measures the brightness of a star as seem from _____. A) Earth / 10 pc B) 10 pc / Earth C) the naked eye / a telescope D) a telescope / the naked eye
B
An eclipsing binary is a binary system that is detected in what way? A) By seeing one of the stars visibly move back and forth over time. B) By seeing the brightness of the star decrease periodically as its companion passes in front of it. C) By directly seeing the two stars of the system. D) By analysis of the absorption spectra of the stars and seeing the radial velocities vary over time
B
In the HR diagram on the x-axis the temperature increases _____. A) Toward right B) Toward left C) In both directions D) Arbitrarily
B
In the Sun, nuclear fusion occurs A) In the core and the radiative zone B) Only in the core C) Throughout the entire star
B
In which layer of the Sun is the continuous (blackbody) spectrum we see produced? A) Core B) Photosphere C) Chromosphere D) Solar Wind
B
Star A and Star B have same size, but Star A is more luminous than Star B. Based on this information, which of the following must be the case? A) Star A is cooler than Star B B) Star A is hotter than Star B C) Star A and Star B have same temperature D) Star A is more massive than Star B
B
The CNO cycle is... A) The hydrogen fusion process that occurs in lightweight stars like our Sun. B) The hydrogen fusion process that occurs in massive stars. C) The helium fusion process that occurs in lightweight stars like our Sun. D) The helium fusion process that occurs in massive stars
B
The energy in the Sun's core is produced by _____. A) Chemical reaction of hydrogen and helium B) Fusion of hydrogen to helium C) Radioactive decay
B
What causes sunspots to occur? A) Oils building up in the pores of the Sun's surface. B) The magnetic field of the Sun emerging from and entering into the Sun's photosphere. C) Convection within the Sun's interior. D) Temperature fluctuations across the Sun's surface
B
What causes the granulation seen in the Sun's photosphere? A) Magnetic loops moving out and back into the Sun. B) Hot material below the photosphere convecting upward and cool material convecting downward. C) Neutrinos interacting with sunspots. D) Magnetic waves.
B
What is a white dwarf composed of? A) just electrons, nothing else. B) mainly carbon nuclei and electrons compressed as tightly as possible. C) neutrons compressed as tightly as possible. D) its just a 'hole' in space-time, a singularity
B
What is interstellar extinction? A) The scattering of a star's red light by the interstellar medium. B) The scattering of a star's blue light by the interstellar medium. C) The red-shifting of a star's spectrum by the doppler effect. D) The dying off of stars in our galaxy until none remain
B
What type of object will be formed by a stellar core whose mass is 2.06 solar masses? A) White dwarf B) Neutron star C) Brown Dwarf D) Black hole
B
When the core temperature of a star reaches _____, hydrogen fusion via the proton-proton chain begins. A) 5800 K B) 10,000,000 K C) 15,000,000 K D) 100,000,000 K
B
Where are elements less massive than iron but more massive than carbon produced? A) In the cores of stars like our Sun. B) In the cores of stars far more massive than our Sun. C) In the cores of stars far less massive than our Sun. D) Along the shockwaves of supernovae
B
Where is the carbon, nitrogen and oxygen seen in stars produced? A) In the cores of stars like our Sun. B) In the cores of stars far more massive than our Sun. C) In the cores of black holes. D) Along the shockwaves of supernovae
B
Where on the HR-Diagram are red giant stars found? A) along the top of the chart B) in the right-center portion of the chart C) in the bottom left corner of the chart D) along a diagonal line from the upper left to the lower right corners
B
Where will stars that are very dim appear on the HR-Diagram? A) along the top B) along the bottom C) on the right side D) on the left side
B
Which of the following objects produces an absoption spectrum? A) Bright nebula B) Absorption nebula C) Planetary nebula D) Dark nebula
B
A Type I Supernova (carbon detonation) is... A) The detonation of a massive star. B) The outward surge that results in a planetary nebula C) The explosion that results when a white dwarf exceeds a mass of 1.44 solar masses. D) The explosion that results when hydrogen fusion is triggered at the center of an accretion disc
C
A method for identifying a black hole is to A) Observe them directly through the space-based telescopes B) Look for voids (holes) in the star fields C) Look for its effect on nearby companions D) Search for radio waves from the accretion disk
C
A red giant star _____. A) Has 100x more mass as our Sun B) Is fusing hydrogen in its core C) Is fusing helium in its core D) Is a luminosity class Ia
C
A visual binary is a binary system that is detected in what way? A) By seeing one of the stars visibly move back and forth over time. B) By seeing the brightness of the star decrease periodically as its companion passes in front of it. C) By directly seeing the two stars of the system. D) By analysis of the absorption spectra of the stars and seeing the radial velocities vary over time
C
In what type of binary system is the transfer of mass between the stars in both directions? A) Detached B) Semi-detached C) Contact D) Eclipsing
C
In which layer of the Sun are the absorption lines seen in the Sun's spectrum produced? A) Core B) Photosphere C) Chromosphere D) Solar Wind
C
Since nuclear fusion in the Sun creates energy from matter, why doesn't it violate the law of conservation of energy? A) Conservation of energy only applies to mechanical and electrical systems, not to nuclear physics. B) The energy actually comes from the motion of the four separate hydrogen atoms, which move less bound together as one helium atom. C) Matter and energy are equivalent, as expressed by Einstein's equation E = mc2. D) It does, but conservation of energy is only a law in Newtonian physics, which does not work under the conditions at the center of the Sun
C
The parallax method for determining distances is ____ that uses the ____ as the baseline. A) An angle; radius of the Earth B) An angle; radius of the Earth's orbit C) A triangulation; astronomical unit D) A triangulation; radius of the Earth
C
The solar cycle is a result of the A) Nuclear fusion at the core of the Sun. B) Loss of energy in the Sun's magnetic field through flares, sunspots, and prominences. C) Differential rotation of the Sun. D) Motion in the convection zone cycling material into the Sun's core.
C
What determines whether a binary star system will be a detached, semi-detached, or a contact binary? A) The total mass of the two stars B) The ratio of the mass of the two stars C) The size of the two stars relative to their Roche Lobes D) The relative brightness of the two stars
C
What is parallax? A) The distance to an object, measured in parsecs B) The difference between the apparent and absolute magnitude C) The apparent shift in position of an object caused by a change in the observer's position D) The shift in angular position of an object as the object actually moves in space
C
What is the escape velocity at the event horizon of a black hole? A) Speed of sound B) Supersonic speed C) Speed of light D) Half the speed of light
C
When do we say that a star is born? A) When the interstellar cloud collapses B) When the interstellar matter achieves the Jeans instability C) When fusion of hydrogen atoms into helium atoms start D) When star leaves the main sequence
C
Which of the following statements are true about multiple-star systems? A) Multiple-star systems are extremely rare. B) Multiple-star systems and single-star systems are equally abundant. C) Multiple-star systems are far more abundant than single-star systems. D) The abundance of multiple-star systems in our galaxy is completely unknown
C
Which part of the Sun is covered with granules and supergranules? A) Corona B) Chromosphere C) Photosphere D) Core
C
_______ are remnants of low mass stars. A) Neutron stars B) Pulsars C) White dwarfs D) Black holes
C
A spectroscopic binary is a binary system that is detected in what way? A) By seeing one of the stars visibly move back and forth over time. B) By seeing the brightness of the star decrease periodically as its companion passes in front of it. C) By directly seeing the two stars of the system. D) By analysis of the absorption spectra of the stars and seeing the radial velocities vary over time
D
Luminosity (absolute brightness) of a star depends on its ___________. A) Temperature B) Radius C) Distance from us D) Both A and B E) Both A and C
D
The layers of our Sun from innermost to outermost are... A) Core, radiative zone, convective zone, corona, chromosphere, photosphere. B) Core, convective zone, radiative zone, corona, chromosphere, photosphere. C) Corona, core, chromosphere, radiative zone, convective zone, photosphere. D) Core, radiative zone, convective zone, photosphere, chromosphere, corona
D
The mass of a black hole can be determined by _____. A) Measuring its volume and density B) Measuring its Schwarzschild radius C) Measuring its Doppler shift D) Applying the modified version of Kepler's 3rd law, if the blackhole is in a binary system
D
The solar wind is basically the same as which layer of the Sun? A) Core B) Photosphere C) Chromosphere D) Corona
D
The space between the stars is known to contain A) A large quantity of dust but no gas at all B) A variable amount of gas but no dust at all C) A perfect vacuum D) Both gas (atomic or molecular) and dust
D
What is a black hole composed of? A) just electrons, nothing else. B) mainly carbon nuclei and electrons compressed as tightly as possible. C) neutrons compressed as tightly as possible. D) its just a 'hole' in space-time, a singularity
D
What is the temperature of our Sun's core? A) 3000 K B) 5800 K C) 10,000,000 K D) 15,000,000 K
D
What particle produced in the core of the Sun allows astronomers to determine details about the types of reactions happening within the core of the Sun? A) Positrons B) Photons (particles of light) C) Neutrons D) Neutrinos
D
What type of object will be formed by a stellar core whose mass is 4.38 solar masses? A) White dwarf B) Neutron star C) Brown Dwarf D) Black hole
D
When a star is in hydrostatic balance, the _____ is equal to the _____. A) Outward pressure of gravity / Inward gas pressure B) Inward pressure of gravity / Outward gas pressure C) Outward pressure of gravity / Inward radiation pressure D) Inward pressure of gravity / Outward radiation pressure
D
When a star like our Sun dies, what will happen to it? A) It will explode in a Type I Supernova. B) It will explode in a Type II Supernova. C) It will become a planetary nebula with a brown dwarf at the center. D) It will become a planetary nebula with a white dwarf at the center
D
When the core temperature of a star reaches _____, helium fusion begins. A) 5800 K B) 10,000,000 K C) 15,000,000 K D) 100,000,000 K
D
Where are elements more massive than iron produced? A) In the cores of stars like our Sun. B) In the cores of stars far more massive than our Sun. C) In the cores of stars far less massive than our Sun. D) Along the shockwaves of supernovae
D
Where on the HR-Diagram are main sequence stars found? A) along the top of the chart B) in the right-center portion of the chart C) in the bottom left corner of the chart D) along a diagonal line from the upper left to the lower right corners
D
Where will stars that have high surface temperatures appear on the HR-Diagram? A) along the top B) along the bottom C) on the right side D) on the left side
D
Which layer of the Sun is also known as the corona? A) Core B) Photosphere C) Chromosphere D) Solar Wind
D
Which of the following is a main sequence star hotter than the Sun? (Note: the Sun is a G2V star) A) B2II B) G2II C) G2III D) G1V E) O2II
D
Which of the following objects appear as a black obscuring cloud? A) Bright nebula B) Absorption nebula C) Planetary nebula D) Dark nebula
D
If a star is in hydrostatic equilibrium A) It is in a stable binary orbit B) It is generating energy at the same rate everywhere C) It is near the end of its life D) It must be losing mass E) Its radiation pressure outwards and gravitational forces inwards are in balance
E
The escape velocity inside a black hole is A) Zero B) Infinity C) Unknown D) Half the speed of light E) Greater than the speed of light
E
Which of the following can actually escape a black hole? A) Electrons B) Very high energy gamma-rays C) Visible light D) Very low energy radio waves E) None of the above
E
