lecture 18, november 2, 2010 astr 101, section 2 instructor, jack brandt jcbrandt@unm.edu 1astr...

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LECTURE 18, NOVEMBER 2, 2010

ASTR 101, SECTION 2INSTRUCTOR, JACK BRANDT

jcbrandt@unm.edu

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a) its core begins fusing iron.b) its supply of hydrogen is used up.c) the carbon core detonates, and it explodes as

a Type I supernova.d) helium builds up in the core, while the

hydrogen-burning shell expands.e) the core loses all of its neutrinos, so all fusion

ceases.

Question 3

The Sun will evolve away from the main sequence when

a) its core begins fusing iron.b) its supply of hydrogen is used up.c) the carbon core detonates, and it explodes as

a Type I supernova.d) helium builds up in the core, while the

hydrogen-burning shell expands.e) the core loses all of its neutrinos, so all fusion

ceases.

Question 3

The Sun will evolve away from the main sequence when

When the Sun’s core becomes unstable and contracts, additional H fusion generates extra pressure, and the star will swell into a red

giant.

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a) red giants.b) pulsars.c) black holes.d) white dwarfs.e) red dwarfs.

Question 1

Stars like our Sun will end their lives as

a) red giants.b) pulsars.c) black holes.d) white dwarfs.e) red dwarfs.

Question 1

Stars like our Sun will end their lives as

Low-mass stars eventually swell into red giants, and their cores

later contract into white dwarfs.

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a) an asteroid.b) a planet the size of Earth.c) a planet the size of Jupiter.d) an object the size of the Moon.e) an object the size of a sugar cube.

Question 8

In a white dwarf, the mass of the Sun is packed into the volume of

a) an asteroid.b) a planet the size of Earth.c) a planet the size of Jupiter.d) an object the size of the Moon.e) an object the size of a sugar cube.

Question 8

In a white dwarf, the mass of the Sun is packed into the volume of

The density of a white dwarf is about a million times greater

than normal solid matter.

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a) mass transfer onto a white dwarf in a binary star system.

b) repeated helium fusion flashes in red giants.c) rapid collapse of a protostar into a massive O star.d) the explosion of a low-mass star.e) the birth of a massive star in a new cluster.

Question 11

A nova involves

a) mass transfer onto a white dwarf in a binary star system.

b) repeated helium fusion flashes in red giants.c) rapid collapse of a protostar into a massive O star.d) the explosion of a low-mass star.e) the birth of a massive star in a new cluster.

Question 11

A nova involves

Sudden, rapid fusion of new fuel dumped onto a white dwarf

causes the star to flare up, and for a short time become much

brighter.

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a) the number of main sequence stars.b) the ratio of giants to supergiants.c) the luminosity of stars at the turnoff point.d) the number of white dwarfs.e) supernova explosions.

Question 6

Astronomers determine the age of star clusters by observing

a) the number of main sequence stars.b) the ratio of giants to supergiants.c) the luminosity of stars at the turnoff point.d) the number of white dwarfs.e) supernova explosions.

Question 6

Astronomers determine the age of star clusters by observing

The H–R diagram of a cluster can indicate its approximate age.

Turnoff point from the main sequence

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a) as a protostar.b) as a red giant.c) as a main-sequence star.d) as a white dwarf.e) evolving from type O to type M.

Question 10

A star will spend most of its “shining” lifetime

a) as a protostar.b) as a red giant.c) as a main-sequence star.d) as a white dwarf.e) evolving from type O to type M.

Question 10

A star will spend most of its “shining” lifetime

In the main-sequence stage, hydrogen fuses to helium.

Pressure from light and heat pushing out balances

gravitational pressure pushing inward.

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