Exam 4

A  an exploding white dwarf

B  a planet atmosphere

C  an expelled shell of gas

D  a small black hole

A  iron

B  silica & sulphur

C  deuterium & tritium

D  carbon & oxygen

E  helium

A  gravity

B  supernova explosions

C  ignition

D  gas & dust

A  emission

B  dust

C  reflection

D  absorption

A  stellar halo

B  spiral arms

C  dark matter halo

D  nuclear bulge

A  Sun-like star

B  Binary system with a white dwarf

C  the collision of two neutron stars or two black holes

D  Supergiant

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  the collision of two neutron stars or two black holes

B  Sun-like star

C  Supergiant

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  the collision of two neutron stars or two black holes

B  Sun-like star

C  Supergiant

D  Binary system with a white dwarf

A  Binary system with a white dwarf

B  the collision of two neutron stars or two black holes

C  Sun-like star

D  Supergiant

A  Sun-like star

B  Binary system with a white dwarf

C  the collision of two neutron stars or two black holes

D  Supergiant

A  TRUE

B  FALSE

A  Mars

B  Uranus

C  Earth

D  Venus

A  the color of the galaxy.

B  the speeds of the stars near the core.

C  the total mass of the galaxy.

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

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

A  collapsing very slowly.

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

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

D  maintaining the same size.

A  TRUE

B  FALSE

A  TRUE

B  FALSE

A  11,700,000 years

B  11,700,000 light years

C  117,000,000 years

D  1,170,000 years

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

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

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

D  Each cluster of galaxies is the same size.

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

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

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

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

A  gravitational funnel

B  Roche Limit

C  center of mass

D  Roche Lobe

A  FALSE

B  TRUE

A  TRUE

B  FALSE

A  Triton

B  Uranus

C  Io

D  Venus

A  FALSE

B  TRUE

A  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.

B  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.

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

D  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.

A  TRUE

B  FALSE

A  dwarf

B  lenticular

C  elliptical

D  irregular

E  spiral

A  passing nebulae (cocoon)

B  outer shells of gas

C  nearby main sequence cluster stars

D  neighboring giant

E  supernovae

A  1

B  1/4

C  4

D  1/16

E  16

A  FALSE

B  TRUE

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

B  Emission nebulae are mostly found in spiral arms.

C  Spiral arms consist mostly of dark matter.

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

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

A  HIII regions

B  Type Ia regions

C  HII regions

D  HI regions

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

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

C  It is an isotope of hydrogen.

D  It has one neutron and one proton.

A  the Galactic halo.

B  globular star clusters.

C  the Galactic bulge.

D  the central supermassive black hole.

E  giant molecular clouds in spiral arms.

A  the core contracts and thus cools down.

B  the core contracts and thus heats up.

C  the core expands and thus cools down.

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

E  the core expands and thus heats up.

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 107
1.2 x 10-1

D  5.6 x 108
1.2 x 10-1

A  a Blue Supergiant

B  a captured galaxy

C  one black hole

D  dust and gas

A  red supergiants

B  super massive black holes

C  white dwarfs

D  sun-like stars

E  Cepheid variables

A  FALSE

B  TRUE

A  All of these answers would work.

B  Find an astrometric binary with a massive companion.

C  Find star(s) orbiting a blank spot.

D  Identify an accretion disk emitting x-rays.

A  dwarf

B  irregular

C  lenticular

D  elliptical

E  spiral

A  the rotation of hydrogen molecules.

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

C  the atomic hydrogen spin-flip transition.

D  dust grains in molecular clouds.

E  carbon monoxide (CO) molecules.

A  dark energy

B  stars, protons, neutrons, electrons

C  dark matter

D  none of these

A  shine only while nuclear reactions continue within them.

B  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.

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

D  consist largely of uranium and other very heavy elements.

E  consist largely of carbon and oxygen.

A  TRUE

B  FALSE

A  New stars generally form in the spiral arms.

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

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

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

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

A  black hole

B  white dwarf

C  supernova

D  neutron star

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

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

C  a red-giant star ejects a planetary nebula.

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

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