Exam 4

A  an expelled shell of gas

B  an exploding white dwarf

C  a planet atmosphere

D  a small black hole

A  silica & sulphur

B  helium

C  carbon & oxygen

D  deuterium & tritium

E  iron

A  ignition

B  gas & dust

C  gravity

D  supernova explosions

A  dust

B  emission

C  reflection

D  absorption

A  nuclear bulge

B  spiral arms

C  dark matter halo

D  stellar halo

A  the collision of two neutron stars or two black holes

B  Supergiant

C  Binary system with a white dwarf

D  Sun-like star

A  Supergiant

B  Binary system with a white dwarf

C  Sun-like star

D  the collision of two neutron stars or two black holes

A  Supergiant

B  the collision of two neutron stars or two black holes

C  Binary system with a white dwarf

D  Sun-like star

A  Supergiant

B  Sun-like star

C  the collision of two neutron stars or two black holes

D  Binary system with a white dwarf

A  Binary system with a white dwarf

B  Sun-like star

C  the collision of two neutron stars or two black holes

D  Supergiant

A  Binary system with a white dwarf

B  the collision of two neutron stars or two black holes

C  Supergiant

D  Sun-like star

A  Sun-like star

B  the collision of two neutron stars or two black holes

C  Binary system with a white dwarf

D  Supergiant

A  TRUE

B  FALSE

A  Uranus

B  Earth

C  Venus

D  Mars

A  the diminished brightness of starlight in the galaxy core, relative to surrounding areas.

B  the distance of the galaxy from the Milky Way Galaxy.

C  the color of the galaxy.

D  the total mass of the galaxy.

E  the speeds of the stars near the core.

A  the Universe is expanding in a linear fashion with constant speed.

B  the Universe is expanding in a exponential fashion, accelerating faster and faster.

C  collapsing very slowly.

D  maintaining the same size.

A  FALSE

B  TRUE

A  FALSE

B  TRUE

A  11,700,000 light years

B  11,700,000 years

C  1,170,000 years

D  117,000,000 years

A  Super-clusters are uniform & homogeneous across the universe.

B  Each cluster of galaxies is the same size.

C  Filaments of galaxies surround voids that have no or very few galaxies inside.

D  Super-clusters expand outward from a Big Bang source.

A  At least some galaxies formed from the joining together (merging) of small groups of stars.

B  Our Milky Way Galaxy and the Andromeda Galaxy are likely to form an elliptical galaxy at some time in the future.

C  Most elliptical galaxies formed within the first few billion years after the big bang.

D  Astronomers can learn about the evolution of galaxies with images of the same galaxies taken by Edwin Hubble in the early 20th century.

E  In the past, there existed a population of small, blue, irregular galaxies that have either merged together or faded from view.

A  center of mass

B  Roche Lobe

C  Roche Limit

D  gravitational funnel

A  TRUE

B  FALSE

A  TRUE

B  FALSE

A  Triton

B  Venus

C  Io

D  Uranus

A  TRUE

B  FALSE

A  If Galaxies Luke and Yoda both satisfy Hubble’s law, and Galaxy Luke’s distance is three times Galaxy Yoda’s distance, then Galaxy Luke is moving away from us three times faster than Galaxy Yoda.

B  Hubble’s law alone implies that as the distance of a particular galaxy increases with time, it moves away from us progressively faster; in other words, it’s accelerating away from us.

C  Despite the expansion of the Universe, pairs of galaxies can still sometimes move toward each other and even merge together.

D  Hubble’s law can be used to determine the lookback times of distant galaxies – that is, how far back in time we are seeing them.

A  FALSE

B  TRUE

A  dwarf

B  irregular

C  elliptical

D  spiral

E  lenticular

A  outer shells of gas

B  nearby main sequence cluster stars

C  supernovae

D  neighboring giant

E  passing nebulae (cocoon)

A  1

B  1/16

C  1/4

D  4

E  16

A  TRUE

B  FALSE

A  Spiral arms consist mostly of dark matter.

B  Clouds of gas and dust are mostly found in spiral arms.

C  Emission nebulae are mostly found in spiral arms.

D  Spiral arms are usually the most prominent features in the disk.

E  Spiral arms contain most of the hot, young, massive stars.

A  HI regions

B  HII regions

C  HIII regions

D  Type Ia regions

A  It has one electron, so it is not an ion.

B  It has one neutron and one proton.

C  It has one more proton than an average hydrogen atom.

D  It is an isotope of hydrogen.

A  the Galactic halo.

B  giant molecular clouds in spiral arms.

C  the Galactic bulge.

D  globular star clusters.

E  the central supermassive black hole.

A  the core expands and thus cools down.

B  the core contracts and thus heats up.

C  the core remains about the same size, but heats up as fusion of helium to carbon begins immediately after the hydrogen fuel is gone.

D  the core expands and thus heats up.

E  the core contracts and thus cools down.

A  TRUE

B  FALSE

A  5.6 x 107
1.2 x 101

B  5.6 x 108
1.2 x 101

C  5.6 x 108
1.2 x 10-1

D  5.6 x 107
1.2 x 10-1

A  a captured galaxy

B  one black hole

C  dust and gas

D  a Blue Supergiant

A  sun-like stars

B  red supergiants

C  super massive black holes

D  Cepheid variables

E  white dwarfs

A  TRUE

B  FALSE

A  Find star(s) orbiting a blank spot.

B  Find an astrometric binary with a massive companion.

C  Identify an accretion disk emitting x-rays.

D  All of these answers would work.

A  irregular

B  lenticular

C  spiral

D  elliptical

E  dwarf

A  dust grains in molecular clouds.

B  carbon monoxide (CO) molecules.

C  the atomic hydrogen spin-flip transition.

D  electrons in hydrogen atoms jumping from the third to the second energy levels.

E  the rotation of hydrogen molecules.

A  none of these

B  dark matter

C  dark energy

D  stars, protons, neutrons, electrons

A  shine only while nuclear reactions continue within them.

B  consist largely of carbon and oxygen.

C  consist largely of uranium and other very heavy elements.

D  are the end states only of stars whose initial mass if much greater than that of the Sun.

E  support themselves against the pull of gravity in the same way as normal stars link the Sun, using the pressure exerted by hot gases within them.

A  FALSE

B  TRUE

A  Rapid motions of stars near the center suggest that it harbors a black hole, millions of times the mass of our Sun.

B  Globular star clusters reside in the halo and contain main-sequence stars spanning all spectral types, from O through M.

C  New stars generally form in the spiral arms.

D  It is difficult to see the central regions of our Galaxy in optical (visible) light because intervening dust absorbs and scatters light.

E  Nebulae such as the Orion Nebula are stellar nurseries – regions where new stars are forming, or recently formed.

A  black hole

B  neutron star

C  white dwarf

D  supernova

A  a red-giant star ejects a planetary nebula.

B  an extremely massive star collapses, and also ejects its outer atmosphere.

C  a neutron star’s magnetic field becomes strong enough to produce two oppositely directed jets of rapidly moving particles.

D  two neutron stars merge, forming a more massive neutron star.

E  matter accreted from a companion star unstably ignites on the surface of a white dwarf