Exam 4

A  a planet atmosphere

B  an expelled shell of gas

C  a small black hole

D  an exploding white dwarf

A  silica & sulphur

B  carbon & oxygen

C  helium

D  iron

E  deuterium & tritium

A  gas & dust

B  ignition

C  supernova explosions

D  gravity

A  emission

B  reflection

C  dust

D  absorption

A  spiral arms

B  nuclear bulge

C  stellar halo

D  dark matter halo

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  the collision of two neutron stars or two black holes

B  Binary system with a white dwarf

C  Supergiant

D  Sun-like star

A  Sun-like star

B  Binary system with a white dwarf

C  Supergiant

D  the collision of two neutron stars or two black holes

A  the collision of two neutron stars or two black holes

B  Binary system with a white dwarf

C  Supergiant

D  Sun-like star

A  the collision of two neutron stars or two black holes

B  Binary system with a white dwarf

C  Supergiant

D  Sun-like star

A  Binary system with a white dwarf

B  Supergiant

C  Sun-like star

D  the collision of two neutron stars or two black holes

A  Supergiant

B  Binary system with a white dwarf

C  the collision of two neutron stars or two black holes

D  Sun-like star

A  TRUE

B  FALSE

A  Venus

B  Mars

C  Uranus

D  Earth

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

B  the speeds of the stars near the core.

C  the total mass of the galaxy.

D  the color of the 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 exponential fashion, accelerating faster and faster.

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

D  maintaining the same size.

A  TRUE

B  FALSE

A  FALSE

B  TRUE

A  11,700,000 years

B  11,700,000 light years

C  117,000,000 years

D  1,170,000 years

A  Each cluster of galaxies is the same size.

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  Super-clusters are uniform & homogeneous across the universe.

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

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

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

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

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

A  center of mass

B  gravitational funnel

C  Roche Limit

D  Roche Lobe

A  TRUE

B  FALSE

A  TRUE

B  FALSE

A  Venus

B  Triton

C  Io

D  Uranus

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  TRUE

B  FALSE

A  irregular

B  spiral

C  elliptical

D  lenticular

E  dwarf

A  nearby main sequence cluster stars

B  outer shells of gas

C  supernovae

D  neighboring giant

E  passing nebulae (cocoon)

A  1/4

B  1/16

C  4

D  1

E  16

A  TRUE

B  FALSE

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

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

C  Spiral arms consist mostly of dark matter.

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

E  Emission nebulae are mostly found in spiral arms.

A  HII regions

B  HIII regions

C  HI regions

D  Type Ia regions

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

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

C  It has one neutron and one proton.

D  It is an isotope of hydrogen.

A  the Galactic halo.

B  giant molecular clouds in spiral arms.

C  the central supermassive black hole.

D  the Galactic bulge.

E  globular star clusters.

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

B  the core expands and thus cools down.

C  the core contracts and thus cools down.

D  the core contracts and thus heats up.

E  the core expands and thus heats up.

A  TRUE

B  FALSE

A  5.6 x 108
1.2 x 10-1

B  5.6 x 108
1.2 x 101

C  5.6 x 107
1.2 x 101

D  5.6 x 107
1.2 x 10-1

A  a captured galaxy

B  dust and gas

C  one black hole

D  a Blue Supergiant

A  white dwarfs

B  Cepheid variables

C  sun-like stars

D  red supergiants

E  super massive black holes

A  FALSE

B  TRUE

A  Identify an accretion disk emitting x-rays.

B  All of these answers would work.

C  Find an astrometric binary with a massive companion.

D  Find star(s) orbiting a blank spot.

A  elliptical

B  irregular

C  lenticular

D  dwarf

E  spiral

A  carbon monoxide (CO) molecules.

B  dust grains in molecular clouds.

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

D  the atomic hydrogen spin-flip transition.

E  the rotation of hydrogen molecules.

A  dark matter

B  stars, protons, neutrons, electrons

C  dark energy

D  none of these

A  shine only while nuclear reactions continue 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  consist largely of carbon and oxygen.

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  TRUE

B  FALSE

A  New stars generally form in the spiral arms.

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

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

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  supernova

C  neutron star

D  white dwarf

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

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

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