AST1002 Chapter 13 Test With
Complete Solution
Consider a group of stars with masses up to eight times the mass of the Sun.
Stars of which masses will end up as pure helium - ANSWER less than 0.4 Mυ
Consider a group of stars with masses up to eight times the mass of the Sun.
Stars of which masses undergo a helium flash - ANSWER 0.4 Mυ to 2 Mυ
only
Consider a group of stars with masses up to eight times the mass of the Sun.
Stars of which masses will pass along the horizontal branch - ANSWER all
stars 0.4 Mυ to 8 Mυ
Consider a group of stars with masses up to eight times the mass of the Sun.
Stars of which masses will pass along the asymptotic giant branch - ANSWER
all stars 0.4 Mυ to 8 Mυ
Low-mass stars can ascend the H-R diagram in two evolutionary phases
called giant phases. What is the difference between them - ANSWER In the
first, the primary production of energy is from hydrogen burning in a shell
around the core. In the second, the primary production of energy is from
helium burning in a shell around the core
What are the main products of helium nuclear fusion in red giant stars -
ANSWER carbon and oxygen nuclei
A star on the asymptotic giant branch (AGB) is a - ANSWER red supergiant
In a star's evolutionary life, the asymptotic giant branch (AGB) is the -
,ANSWER helium shell fusion phase
How much brighter than its main-sequence luminosity will a Sun-like star
become at the asymptotic giant branch (AGB) phase of its life - ANSWER
10^4 times brighter
The characteristics of a red supergiant star are the brightness of _____ and a
diameter of _____ - ANSWER 10,000 Suns; about Mars's orbit
In the process of helium shell fusion in a low-mass star near the end of its
life, the star moves upward and to the right on the asymptotic giant branch
of the Hertzsprung-Russell diagram. In this process, the star is - ANSWER
expanding, cooling, and becoming more luminous
In astronomical terms, planetary nebulae are - ANSWER very short-lived, with
lifetimes of about 50,000 years
Which of the following important components does a planetary nebula
contribute to the interstellar medium - ANSWER nuclei of moderately heavy
elements, major components of planets such as our own
A planetary nebula is a(n) - ANSWER expanding gas shell surrounding a hot,
burned-out stellar core
The light from the expanding shell of gas in a planetary nebula consists of -
ANSWER bright emission lines of hydrogen, carbon, nitrogen, and other
elements
What is the difference between a helium flash and a helium shell flash -
ANSWER A helium flash occurs just once; a helium shell flash can repeat
many times
The fraction of the mass of a low-mass star that is ejected in its evolutionary
, phases, up to and including the planetary nebula phase, is - ANSWER
significant, up to 80%
The shell of a planetary nebula is measured by the Doppler shift of emission
lines to be expanding outward at a speed of 104 m/s, while its radius is
measured to be 1 ly, or about 1016 m. Roughly how long has the shell been
expanding? (Hint: 1 year = 3.15 × 107 sec.) - ANSWER 30,000 years
How much mass are planetary nebulae estimated to return to the interstellar
medium each year over the Galaxy as a whole - ANSWER about 5 solar
masses
What percentage of all matter ejected into the interstellar medium in the
Milky Way Galaxy each year by stars is contributed by planetary nebulae -
ANSWER between 10 and 20%
Planetary nebulae are so named because - ANSWER they were extended
objects, often green-colored, that looked like planets when first seen by
nineteenth-century observers through their telescopes
The two longest stages in the lifetime of a solar-mass star, each lasting
billions of years, are - ANSWER Main sequence and white dwarf
Usually, ideal gases increase their pressure and volume when heated and
decrease their pressure and volume when cooled. Do these rules apply to
stars - ANSWER No. White dwarfs are essentially degenerate matter in which
the pressure is independent of the temperature
White dwarfs radiate most strongly in the ultraviolet, with a peak wavelength
of perhaps 300 nm. What would be the surface temperature of a white dwarf
- ANSWER 9700 K
Complete Solution
Consider a group of stars with masses up to eight times the mass of the Sun.
Stars of which masses will end up as pure helium - ANSWER less than 0.4 Mυ
Consider a group of stars with masses up to eight times the mass of the Sun.
Stars of which masses undergo a helium flash - ANSWER 0.4 Mυ to 2 Mυ
only
Consider a group of stars with masses up to eight times the mass of the Sun.
Stars of which masses will pass along the horizontal branch - ANSWER all
stars 0.4 Mυ to 8 Mυ
Consider a group of stars with masses up to eight times the mass of the Sun.
Stars of which masses will pass along the asymptotic giant branch - ANSWER
all stars 0.4 Mυ to 8 Mυ
Low-mass stars can ascend the H-R diagram in two evolutionary phases
called giant phases. What is the difference between them - ANSWER In the
first, the primary production of energy is from hydrogen burning in a shell
around the core. In the second, the primary production of energy is from
helium burning in a shell around the core
What are the main products of helium nuclear fusion in red giant stars -
ANSWER carbon and oxygen nuclei
A star on the asymptotic giant branch (AGB) is a - ANSWER red supergiant
In a star's evolutionary life, the asymptotic giant branch (AGB) is the -
,ANSWER helium shell fusion phase
How much brighter than its main-sequence luminosity will a Sun-like star
become at the asymptotic giant branch (AGB) phase of its life - ANSWER
10^4 times brighter
The characteristics of a red supergiant star are the brightness of _____ and a
diameter of _____ - ANSWER 10,000 Suns; about Mars's orbit
In the process of helium shell fusion in a low-mass star near the end of its
life, the star moves upward and to the right on the asymptotic giant branch
of the Hertzsprung-Russell diagram. In this process, the star is - ANSWER
expanding, cooling, and becoming more luminous
In astronomical terms, planetary nebulae are - ANSWER very short-lived, with
lifetimes of about 50,000 years
Which of the following important components does a planetary nebula
contribute to the interstellar medium - ANSWER nuclei of moderately heavy
elements, major components of planets such as our own
A planetary nebula is a(n) - ANSWER expanding gas shell surrounding a hot,
burned-out stellar core
The light from the expanding shell of gas in a planetary nebula consists of -
ANSWER bright emission lines of hydrogen, carbon, nitrogen, and other
elements
What is the difference between a helium flash and a helium shell flash -
ANSWER A helium flash occurs just once; a helium shell flash can repeat
many times
The fraction of the mass of a low-mass star that is ejected in its evolutionary
, phases, up to and including the planetary nebula phase, is - ANSWER
significant, up to 80%
The shell of a planetary nebula is measured by the Doppler shift of emission
lines to be expanding outward at a speed of 104 m/s, while its radius is
measured to be 1 ly, or about 1016 m. Roughly how long has the shell been
expanding? (Hint: 1 year = 3.15 × 107 sec.) - ANSWER 30,000 years
How much mass are planetary nebulae estimated to return to the interstellar
medium each year over the Galaxy as a whole - ANSWER about 5 solar
masses
What percentage of all matter ejected into the interstellar medium in the
Milky Way Galaxy each year by stars is contributed by planetary nebulae -
ANSWER between 10 and 20%
Planetary nebulae are so named because - ANSWER they were extended
objects, often green-colored, that looked like planets when first seen by
nineteenth-century observers through their telescopes
The two longest stages in the lifetime of a solar-mass star, each lasting
billions of years, are - ANSWER Main sequence and white dwarf
Usually, ideal gases increase their pressure and volume when heated and
decrease their pressure and volume when cooled. Do these rules apply to
stars - ANSWER No. White dwarfs are essentially degenerate matter in which
the pressure is independent of the temperature
White dwarfs radiate most strongly in the ultraviolet, with a peak wavelength
of perhaps 300 nm. What would be the surface temperature of a white dwarf
- ANSWER 9700 K
