Exam 4

A  an exploding white dwarf

B  a small black hole

C  a planet atmosphere

D  an expelled shell of gas

A  deuterium & tritium

B  helium

C  silica & sulphur

D  iron

E  carbon & oxygen

A  gravity

B  gas & dust

C  supernova explosions

D  ignition

A  emission

B  reflection

C  absorption

D  dust

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  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  the collision of two neutron stars or two black holes

B  Binary system with a white dwarf

C  Sun-like star

D  Supergiant

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  Binary system with a white dwarf

B  Sun-like star

C  Supergiant

D  the collision of two neutron stars or two black holes

A  Sun-like star

B  Supergiant

C  Binary system with a white dwarf

D  the collision of two neutron stars or two black holes

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  TRUE

B  FALSE

A  Venus

B  Uranus

C  Mars

D  Earth

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

B  the total mass of the galaxy.

C  the color of the galaxy.

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

E  the speeds of the stars near the core.

A  collapsing very slowly.

B  maintaining the same size.

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

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

A  FALSE

B  TRUE

A  TRUE

B  FALSE

A  117,000,000 years

B  11,700,000 years

C  1,170,000 years

D  11,700,000 light years

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

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

C  Each cluster of galaxies is the same size.

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

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

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

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

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

A  Roche Limit

B  gravitational funnel

C  center of mass

D  Roche Lobe

A  TRUE

B  FALSE

A  FALSE

B  TRUE

A  Triton

B  Uranus

C  Io

D  Venus

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  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  FALSE

B  TRUE

A  spiral

B  dwarf

C  irregular

D  elliptical

E  lenticular

A  supernovae

B  passing nebulae (cocoon)

C  nearby main sequence cluster stars

D  outer shells of gas

E  neighboring giant

A  1

B  4

C  16

D  1/4

E  1/16

A  TRUE

B  FALSE

A  Emission nebulae are mostly found in spiral arms.

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

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

D  Spiral arms consist mostly of dark matter.

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

A  HI regions

B  HIII regions

C  Type Ia regions

D  HII 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  giant molecular clouds in spiral arms.

B  the Galactic bulge.

C  globular star clusters.

D  the central supermassive black hole.

E  the Galactic halo.

A  the core contracts and thus cools down.

B  the core contracts and thus heats up.

C  the core expands and thus heats up.

D  the core expands and thus cools down.

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

A  TRUE

B  FALSE

A  5.6 x 107
1.2 x 10-1

B  5.6 x 107
1.2 x 101

C  5.6 x 108
1.2 x 101

D  5.6 x 108
1.2 x 10-1

A  one black hole

B  a captured galaxy

C  a Blue Supergiant

D  dust and gas

A  white dwarfs

B  sun-like stars

C  super massive black holes

D  Cepheid variables

E  red supergiants

A  TRUE

B  FALSE

A  Identify an accretion disk emitting x-rays.

B  Find an astrometric binary with a massive companion.

C  All of these answers would work.

D  Find star(s) orbiting a blank spot.

A  spiral

B  elliptical

C  dwarf

D  irregular

E  lenticular

A  dust grains in molecular clouds.

B  the rotation of hydrogen molecules.

C  the atomic hydrogen spin-flip transition.

D  carbon monoxide (CO) molecules.

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

A  stars, protons, neutrons, electrons

B  none of these

C  dark matter

D  dark energy

A  consist largely of carbon and oxygen.

B  shine only while nuclear reactions continue 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  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  It is difficult to see the central regions of our Galaxy in optical (visible) light because intervening dust absorbs and scatters light.

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  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  black hole

B  supernova

C  neutron star

D  white dwarf

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

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

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  a red-giant star ejects a planetary nebula.