The best-known example of a ring galaxy is the Cartwheel galaxy. This was likely formed by:
the merger of two spiral galaxies of equal mass.
an elliptical galaxy evolving into a spiral galaxy.
the head-on collision between a small galaxy and a disk galaxy.
a central black hole eating away at the center of the galaxy, producing a ring.
two equal-mass spiral galaxies interacting, producing tidal tails that resemble a ring.
A galaxy with a large bulge relative to the disk and tightly wrapped spiral arms is most likely a/an:
Sc galaxy.
E0 galaxy.
S0 galaxy.
Sd galaxy.
Sa galaxy.
Who was the first person to classify spiral and elliptical galaxies into sub-types according to their appearance?
Henrietta Leavitt.
Harlow Shapley.
Edwin Hubble.
William Herschel.
Robert Trumpler.
The long tails seen in visible light photographs of the Antennae galaxies were produced from:
tidal forces during the collision of two spiral galaxies.
tidal forces during the collision of two elliptical galaxies.
jets of charged particles from a massive black hole.
the head-on collision of a dwarf elliptical galaxy and a disk galaxy.
the galaxy probably originally formed in that shape, for unknown reasons.
When a small galaxy passes through the center of the disk of a large spiral galaxy, traveling in a direction perpendicular to the plane of the disk:
a ring galaxy is formed.
many of the stars in the two galaxies collide, causing numerous supernova.
all of the stars from the small galaxy fall into the central black hole of the larger galaxy.
an elliptical galaxy is formed.
the small galaxy hits the large galaxy, and bounces back in the direction it came from.
The Hubble Tuning Fork diagram is:
a plot of velocity vs. distance.
a diagram showing the different types of galaxies, in order from ellipticals to irregulars.
a map of the Local Group.
a plot of velocity vs. Right Ascension.
a `slice of the Universe' plot.
Rotation curves of galaxies are plots of:
Orbital period vs. Hubble type.
Number of stars vs. distance from center.
Circular orbital velocity vs. distance from center.
Hubble type vs. roundness of shape.
Hubble type vs. circular orbital velocity.
The massive black hole in the center of our galaxy is called:
Cygnus X-1.
The Schwarzchild object.
L.G.M.
RR Lyrae.
Sagittarius A*.
Collisions between galaxies:
cause large numbers of stars to collide, and therefore explode.
turn ellipticals into spirals.
may trigger the formation of many new stars.
almost never occur.
may occur, but there is no evidence for them.
An Sb galaxy is:
a giant elliptical galaxy with huge megaparsec-long jets shooting out of the center.
a galaxy similar to the Milky Way.
a spiral galaxy with an extremely luminous nucleus.
a spiral galaxy with a pulsar in the center.
a pair of galaxies connected by a stellar bridge, with long stellar tails extending out into space.
Evidence for dark matter in the Universe includes:
lots of gamma rays coming from random directions in the sky.
the fast orbital velocities of the planets around the Sun.
the fast orbital velocities of gas and stars in the outer part of the Milky Way.
there is no observational evidence for dark matter; it is just a theoretical idea.
the existence of pulsars.
The ring-like structure of the Cartwheel galaxy was probably formed by:
a massive black hole in the center of the galaxy devoured the stars in the inner part of the galaxy, leaving only an outer ring remaining.
a smaller galaxy passed through the center, creating a ring.
it probably collided with another galaxy more massive than itself.
the stars in the inner regions exploded as supernovae, leaving a large hole in the center.
scientists have no idea why this galaxy has a ring-like structure.
The instability strip is:
a spiral wave pattern in a galaxy.
the boundary around a black hole: the point of no return.
the part of the H-R diagram where Cepheid variables and RR Lyrae stars lie.
in a binary pair, the position where the gravitational pull of the two stars is equal.
the upper mass limit to a white dwarf.
In the Milky Way, almost all interstellar gas clouds are found:
Only in the halo.
In the bulge, disk, and halo.
Only in the disk.
Only in the bulge.
Only in the spiral arms.
What observations did Harlow Shapley make that indicated that the Sun was not the center of the Milky Way?
observations of the angular sizes of open clusters.
observations of variable stars in nearby galaxies.
observations of variable stars in globular clusters.
observations of interstellar dust clouds.
he counted up the number of individual stars in many directions in the sky.
What produces the 21 cm radio line used to map the rotation curve of the Milky Way?
atomic hydrogen.
ionized hydrogen.
molecular hydrogen.
carbon monoxide.
interstellar dust.
Compared with the Sun, most stars in the halo of the Milky Way are:
younger, redder, and have less heavy chemical elements.
younger, bluer, and have more heavy chemical elements.
older, redder, and have less heavy chemical elements.
older, bluer, and have more heavy chemical elements.
older, redder, and have more heavy chemical elements.
What is the evidence for dark matter in the Milky Way Galaxy?
There is much more infrared radiation coming from the Milky Way than can be accounted for by the known normal stars and interstellar clouds.
There is much more visible light coming from the Milky Way than can be accounted for by the known normal stars and interstellar clouds.
There is much more radio waves coming from the Milky Way than can be accounted for by the known normal stars and interstellar clouds.
The circular velocities of gas and stars in the outer part of the Milky Way are higher than can be accounted for by the known stars and interstellar clouds.
The circular velocities of gas and stars in the outer part of the Milky Way are less than can be accounted for by the known stars and interstellar clouds.
The mass of the Milky Way Galaxy is about:
2 X 10^8 solar masses
2 X 10^6 solar masses
6 X 10^11 solar masses
6000 solar masses
2 X 10^4 solar masses
Which of the following are generally only found in the disk and spiral arms of the Milky Way?
O and B stars.
globular clusters.
0.3 solar mass main sequence stars.
white dwarf stars.
KV and MV stars.
Cepheid variable stars are:
are used to determine the distances to other galaxies.
are less luminous than RR Lyrae stars.
are main sequence O stars.
vary with periods of about 1-10 seconds.
all of the above.
Approximately how long does it take the Sun to orbit the Milky Way?
4.6 billion years.
225 million years.
1 million years.
1000 years.
10 years.
In the Milky Way, globular clusters are found:
In the bulge, halo, and disk.
Only in dense molecular clouds.
The Sun's location in the Milky Way is:
near the center.
in the halo.
in the disk, about two-thirds of the way out from the center.
in the bulge.
in a globular cluster.
If all the stars in the bulge of the Milky Way were replaced by a black hole with the same mass, then:
The Sun would be drawn into this black hole.
The velocity at which the Sun orbits the Galactic Center would decrease.
The velocity at which the Sun orbits the Galactic Center would increase.
The velocity at which the Sun orbits the Galactic Center would stay the same.
The Sun would fly off in a straight line into intergalactic space.
In the Milky Way, HII regions are found:
In the bulge and disk, but not in the halo.
What astronomical accomplishment is Henrietta Leavitt best remembered for?
She mapped the distribution of globular clusters in the Milky Way using RR Lyrae stars, and showed that the Sun was NOT in the center of the Milky Way.
She estimated the distance to the Andromeda galaxy using Cepheid variable stars, and found it was OUTSIDE the Milky Way.
She discovered the period-luminosity relationship for Cepheid variable stars.
She was the first person to look at the Milky Way with a telescope, and showed that it is made up of many stars.
She discovered the four biggest moons of Jupiter.
Approximately how many times has the Sun orbited the Milky Way?
a billion times.
a million times.
20 times.
1 time.
it has never orbited the Milky Way; during the entire life of the Sun, it has only moved a tiny fraction of the full circumference of the Milky Way.
An RR Lyrae star is:
An eclipsing binary star.
A white dwarf in a mass-transfer binary system.
A neutron star in a mass-transfer binary system.
A variable star which can be used for distance determination.
A post-AGB star.
Jupiter has a mass about 300 times the mass of the Earth. If Jupiter turned into a black hole with the same mass, but nothing else changed,
its moon Europa would be pulled into the black hole.
its moon would orbit around Jupiter at a distance equal to the Schwarzchild radius of the black hole.
Europa would continue in its same orbit.
the entire solar system would be pulled into this black hole.
the Schwarzchild radius of this black hole would be about 3000 km.
The "point of no return" around a black hole, inside which one cannot escape from, is called the:
The Chandrasekhar limit.
The Lagrange point.
The gravitational lens.
The event horizon.
The Pauli Exclusion limit.
Imagine you are in a rocketship, about 10 Schwarzchild radii away from a black hole. Which of the following would you NEVER observe?
X-ray radiation coming out from within the Schwarzchild radius of the black hole.
A shift in the apparent position of nearby stars, due to the gravitational effect of the black hole.
Very strong tidal forces from the black hole.
A shift in the wavelength of light from stars in the direction opposite that of the black hole.
Your clocks will run slower than clocks back home on Earth.
Which of the following has the smallest radius?
a 1 solar mass white dwarf.
a 2 solar mass neutron star.
a 1 solar mass black hole.
a 100 solar mass black hole.
a million solar mass black hole.
The Schwarzchild radius of a black hole is:
The radius of the singularity.
The distance between the black hole and its associated white hole.
The radius of the event horizon.
The distance from the black hole where the gravitational field from the black hole is zero.
The distance from the black hole at which you would be pulled apart by tidal forces.
Harlow Shapley:
Provided the first conclusive evidence that `spiral nebulae' are outside the Milky Way.
Identified the emission lines from pulsars.
Discovered the Period-Luminosity relation for Cepheid variables.
Measured the distances to globular clusters, and concluded the Sun was NOT in the center of the Milky Way.
Made a 3-dimensional map of the Milky Way by counted stars and estimating brightnesses, and concluded that the Sun WAS in the center of the Milky Way.
Henrietta Leavitt:
The diameter of the disk of the Milky Way is approximately:
300 A.U.
10 light years.
100 thousand light years.
a billion light years.
a billion billion light years.
Where in the Milky Way are Type II supernovae usually located?
only in the disk.
only in the halo.
only at the very center.
only in the bulge.
in the disk, halo, and bulge.
From the orbital velocity of the Sun around the Milky Way, 220 km/s, and the distance from the Sun to the center of the Galaxy, using the relationship V2 = GM/R, one can calculate a mass. This is the mass of:
the Sun.
Sgr A*.
the entire Milky Way.
the part of the Milky Way that is outside of the Sun's orbit.
the part of the Milky Way galaxy that is inside of the Sun's orbit.
Synchrotron radiation is produced by:
a hot solid object, like the filament in a light bulb.
electrons in atoms jumping from lower energy levels to higher energy levels.
electrons in atoms jumping from higher energy levels to lower energy levels.
nuclear fusion only.
accelerated charged particles.
Who discovered the period-luminosity relationship for Cepheid variable stars?
Adriaan van Maanen.
Who first measured the distances to globular clusters, and concluded that the Sun was NOT in the center of the Milky Way?
Adriaan van Manaan.
Which of the following objects are NOT generally found in the bulge of the Milky Way, but only in the disk?
planetary nebulae.
open clusters.
white dwarfs.
Supernovae Type I.
Sagittarius A* is:
the brightest supernovae seen in the last 300 years.
a small irregular galaxy in orbit around the Milky Way.
a 10 solar mass black hole in a mass-transfer binary system with a giant star.
a 2 million solar mass black hole in the center of the Milky Way.
the first pulsar ever discovered.
A black hole is:
the end stage of stellar evolution for an isolated 1 solar mass star.
produced during a nova.
produced by an explosion of a white dwarf in a mass transfer system.
a really massive object (greater than 106 solar masses).
an object with an escape velocity greater than the speed of light.
When a charged particle is accelerated, it produces light. This kind of light is called:
Heat radiation.
Thermal radiation.
Synchrotron radiation.
Magnetic radiation.
RR radiation.
What provided the first evidence of the existence of large quantities of dark matter in the Universe?
The light curves of galaxies.
The rotation curves of galaxies.
Mapping the distribution of globular clusters in the Milky Way.
The discovery of the period-luminosity relationship for Cepheids.
The discovery of pulsars.
a white dwarf star undergoing mass transfer from a companion.
a neutron star undergoing mass transfer from a companion.
a star that lies above the main sequence on an HR diagram, in the instability strip.
a white dwarf that has cooled to become very dim.
a neutron star with a beam of light that regularly sweeps across the Earth.
The radius of the event horizon of a black hole is called the:
Shapley radius.
Synchrotron radius.
Pauli radius.
Schwarzchild radius.
Wormhole radius.
What phenomenon was observed during the 1919 total solar eclipse?
The positions of stars behind the Sun appeared shifted.
The velocity of the light from stars near the Sun appeared faster than normal.
The velocity of the light from stars near the Sun appeared slower than normal.
Light from the Sun was observed to be gravitationally blueshifted.
All of the above.
How far is the Sun from the center of the Milky Way?
8 light years.
8 parsecs.
8 kiloparsecs.
8 A.U.
the Sun is at the center of the Milky Way.
Who made the first map of the Milky Way by using his telescope to count the stars towards many directions in the sky?
On the H-R diagram, Cepheids variables lie:
below and to the left of the main sequence.
below and to the right of the main sequence.
on the far right above the main sequence, in the MIII star region.
on the main sequence, in the upper left of the diagram.
above the main sequence in the instability strip.
Most of the following objects are mainly found in the plane of the disk of the Milky Way, but usually not in the bulge or the halo. Which is the exception, being commonly found in the bulge and halo as well as the disk?
HII regions.
Molecular clouds.
Open clusters.
Globular clusters.
The first person to find evidence that the Sun is not in the center of the Milky Way was:
