Astronomy 3

What law causes stars to spin more rapidly as they contract?

Conservation of Angular Momentum

When astronomers carefully examine the planets found by Kepler and draw conclusions from the Kepler sample, what do they conclude about planets the size of Earth?

Earth-sized planets are common, but so are planets somewhat bigger than Earth

Which of the following statements about the mass of the Sun during its lifetime is correct?

The Sun will lose a significant amount of mass during and after its red giant phase

The larger the star, the shorter its lifetime.

True

The Orion Nebula is

a large cloud of gas and dust illuminated by the light of newly formed stars within it

Elements heavier than iron can be created during:

a supernova explosion

The event in the life of a star that begins its expansion into a giant is

almost all the hydrogen in its core that was hot enough for fusion has been turned into helium

Planets in the habitable zone of their stars:

are at a temperature where water can exist as a liquid

Which of the following statements about the life of a star with a mass like the Sun is correct?

as the star is dying, a considerable part of its mass will be lost into space

Why can a star with a mass like our Sun not fuse (produce) further elements beyond carbon and oxygen?

because they just cannot get hot enough for the fusion of heavier nuclei

Really massive stars differ from stars with masses like the Sun in that they

can fuse elements beyond carbon and oxygen in their hot central regions

After the core of a massive star becomes a neutron star, the rest of the star's material

explodes outward as a supernova

If stars with masses like our Sun's cannot make elements heavier than oxygen, where are heavier elements like silicon produced in the universe?

heavier elements are made in the cores of significantly more massive stars than the Sun, which can get hotter in the middle

The most stable (tightly bound) atomic nucleus in the universe is:

iron

If you trace back the history of a carbon atom in your body through all of cosmic history, where did this atom most likely originate?

it was fused from 3 helium nuclei in the core of a red giant star long before the Sun existed

In a collapsing star of high mass, when electrons and protons are squeezed together with enormous force, they turn into a neutron and a:

neutrino

Which of the following is NOT one of the reasons planets around other stars are so difficult to detect?

planets only form very late in the life of a star, just when it is ready to die, and thus last only a very short fraction of the star's life

Why is it easier for red giants to lose mass than main sequence stars?

red giants are so big, the gravity at their surface (that holds material to the star) is less

Astronomer have concluded that pulsars are

rotating neutron stars

What observations about disks of dusty material around young stars suggest that planets may be forming in such disks?

the disks are making the stars "wiggle" -- move back and forth across the sky -- in a way that can be observed even with small telescopes

Which of the following is a characteristic of degenerate matter in a white dwarf star?

the electrons get as close to each other as possible and resist further compression

Which of the following is NOT a result of supernova explosions?

the neutron star is disrupted and tears apart into many pieces

How were the gold atoms found on the Earth formed?

they were built up from smaller nuclei during a supernova explosion

When a single star with a mass equal to the Sun dies, it will become a

white dwarf