Exam 4

A  a small black hole

B  an exploding white dwarf

C  a planet atmosphere

D  an expelled shell of gas

A  helium

B  silica & sulphur

C  carbon & oxygen

D  deuterium & tritium

E  iron

A  supernova explosions

B  gravity

C  ignition

D  gas & dust

A  emission

B  absorption

C  reflection

D  dust

A  nuclear bulge

B  spiral arms

C  stellar halo

D  dark matter halo

A  Sun-like star

B  Supergiant

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  the collision of two neutron stars or two black holes

C  Sun-like star

D  Supergiant

A  the collision of two neutron stars or two black holes

B  Supergiant

C  Sun-like star

D  Binary system with a white dwarf

A  Sun-like star

B  the collision of two neutron stars or two black holes

C  Supergiant

D  Binary system with a white dwarf

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  Sun-like star

B  the collision of two neutron stars or two black holes

C  Supergiant

D  Binary system with a white dwarf

A  FALSE

B  TRUE

A  Uranus

B  Venus

C  Earth

D  Mars

A  the total mass of the galaxy.

B  the speeds of the stars near the core.

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

D  the color of the galaxy.

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

A  maintaining the same size.

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

C  collapsing very slowly.

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

A  TRUE

B  FALSE

A  FALSE

B  TRUE

A  1,170,000 years

B  11,700,000 years

C  11,700,000 light years

D  117,000,000 years

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

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

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

D  Each cluster of galaxies is the same size.

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

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

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

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

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

A  Roche Lobe

B  Roche Limit

C  gravitational funnel

D  center of mass

A  TRUE

B  FALSE

A  FALSE

B  TRUE

A  Triton

B  Uranus

C  Venus

D  Io

A  TRUE

B  FALSE

A  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.

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  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.

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

A  FALSE

B  TRUE

A  elliptical

B  dwarf

C  lenticular

D  spiral

E  irregular

A  outer shells of gas

B  nearby main sequence cluster stars

C  supernovae

D  passing nebulae (cocoon)

E  neighboring giant

A  4

B  1/4

C  16

D  1

E  1/16

A  TRUE

B  FALSE

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

B  Spiral arms consist mostly of dark matter.

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

D  Emission nebulae are mostly found in spiral arms.

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

A  HI regions

B  Type Ia regions

C  HIII regions

D  HII regions

A  It has one neutron and one proton.

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

C  It is an isotope of hydrogen.

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

A  the Galactic halo.

B  globular star clusters.

C  giant molecular clouds in spiral arms.

D  the central supermassive black hole.

E  the Galactic bulge.

A  the core expands and thus cools down.

B  the core contracts and thus cools down.

C  the core contracts and thus heats up.

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  dust and gas

B  a Blue Supergiant

C  a captured galaxy

D  one black hole

A  Cepheid variables

B  white dwarfs

C  super massive black holes

D  sun-like stars

E  red supergiants

A  TRUE

B  FALSE

A  Find an astrometric binary with a massive companion.

B  Find star(s) orbiting a blank spot.

C  Identify an accretion disk emitting x-rays.

D  All of these answers would work.

A  elliptical

B  irregular

C  spiral

D  dwarf

E  lenticular

A  dust grains in molecular clouds.

B  the atomic hydrogen spin-flip transition.

C  carbon monoxide (CO) molecules.

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

E  the rotation of hydrogen molecules.

A  stars, protons, neutrons, electrons

B  dark matter

C  dark energy

D  none of these

A  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.

B  consist largely of uranium and other very heavy elements.

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

D  shine only while nuclear reactions continue within them.

E  consist largely of carbon and oxygen.

A  TRUE

B  FALSE

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

D  New stars generally form in the spiral arms.

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

A  supernova

B  neutron star

C  black hole

D  white dwarf

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

B  a red-giant star ejects a planetary nebula.

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

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

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