Taylor Campbell
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Test sobre ASTR 2020 Quiz 5, creado por Taylor Campbell el 14/04/2015.

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ASTR 2020 Quiz 5

Pregunta 1 de 55

1

The best-known example of a ring galaxy is the Cartwheel galaxy. This was likely formed by:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 2 de 55

1

A galaxy with a large bulge relative to the disk and tightly wrapped spiral arms is most likely a/an:

Selecciona una de las siguientes respuestas posibles:

  • Sc galaxy.

  • E0 galaxy.

  • S0 galaxy.

  • Sd galaxy.

  • Sa galaxy.

Explicación

Pregunta 3 de 55

1

Who was the first person to classify spiral and elliptical galaxies into sub-types according to their appearance?

Selecciona una de las siguientes respuestas posibles:

  • Henrietta Leavitt.

  • Harlow Shapley.

  • Edwin Hubble.

  • William Herschel.

  • Robert Trumpler.

Explicación

Pregunta 4 de 55

1

The long tails seen in visible light photographs of the Antennae galaxies were produced from:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 5 de 55

1

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:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 6 de 55

1

The Hubble Tuning Fork diagram is:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 7 de 55

1

Rotation curves of galaxies are plots of:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 8 de 55

1

The massive black hole in the center of our galaxy is called:

Selecciona una de las siguientes respuestas posibles:

  • Cygnus X-1.

  • The Schwarzchild object.

  • L.G.M.

  • RR Lyrae.

  • Sagittarius A*.

Explicación

Pregunta 9 de 55

1

Collisions between galaxies:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 10 de 55

1

An Sb galaxy is:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 11 de 55

1

Evidence for dark matter in the Universe includes:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 12 de 55

1

The ring-like structure of the Cartwheel galaxy was probably formed by:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 13 de 55

1

The instability strip is:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 14 de 55

1

In the Milky Way, almost all interstellar gas clouds are found:

Selecciona una de las siguientes respuestas posibles:

  • Only in the halo.

  • In the bulge, disk, and halo.

  • Only in the disk.

  • Only in the bulge.

  • Only in the spiral arms.

Explicación

Pregunta 15 de 55

1

What observations did Harlow Shapley make that indicated that the Sun was not the center of the Milky Way?

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 16 de 55

1

What produces the 21 cm radio line used to map the rotation curve of the Milky Way?

Selecciona una de las siguientes respuestas posibles:

  • atomic hydrogen.

  • ionized hydrogen.

  • molecular hydrogen.

  • carbon monoxide.

  • interstellar dust.

Explicación

Pregunta 17 de 55

1

Compared with the Sun, most stars in the halo of the Milky Way are:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 18 de 55

1

What is the evidence for dark matter in the Milky Way Galaxy?

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 19 de 55

1

The mass of the Milky Way Galaxy is about:

Selecciona una de las siguientes respuestas posibles:

  • 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

Explicación

Pregunta 20 de 55

1

Which of the following are generally only found in the disk and spiral arms of the Milky Way?

Selecciona una de las siguientes respuestas posibles:

  • O and B stars.

  • globular clusters.

  • 0.3 solar mass main sequence stars.

  • white dwarf stars.

  • KV and MV stars.

Explicación

Pregunta 21 de 55

1

Cepheid variable stars are:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 22 de 55

1

Approximately how long does it take the Sun to orbit the Milky Way?

Selecciona una de las siguientes respuestas posibles:

  • 4.6 billion years.

  • 225 million years.

  • 1 million years.

  • 1000 years.

  • 10 years.

Explicación

Pregunta 23 de 55

1

In the Milky Way, globular clusters are found:

Selecciona una de las siguientes respuestas posibles:

  • In the bulge, halo, and disk.

  • Only in the disk.

  • Only in the halo.

  • Only in the spiral arms.

  • Only in dense molecular clouds.

Explicación

Pregunta 24 de 55

1

The Sun's location in the Milky Way is:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 25 de 55

1

If all the stars in the bulge of the Milky Way were replaced by a black hole with the same mass, then:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 26 de 55

1

In the Milky Way, HII regions are found:

Selecciona una de las siguientes respuestas posibles:

  • Only in the halo.

  • In the bulge, disk, and halo.

  • Only in the disk.

  • Only in the bulge.

  • In the bulge and disk, but not in the halo.

Explicación

Pregunta 27 de 55

1

What astronomical accomplishment is Henrietta Leavitt best remembered for?

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 28 de 55

1

Approximately how many times has the Sun orbited the Milky Way?

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 29 de 55

1

An RR Lyrae star is:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 30 de 55

1

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,

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 31 de 55

1

The "point of no return" around a black hole, inside which one cannot escape from, is called the:

Selecciona una de las siguientes respuestas posibles:

  • The Chandrasekhar limit.

  • The Lagrange point.

  • The gravitational lens.

  • The event horizon.

  • The Pauli Exclusion limit.

Explicación

Pregunta 32 de 55

1

Imagine you are in a rocketship, about 10 Schwarzchild radii away from a black hole. Which of the following would you NEVER observe?

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 33 de 55

1

Which of the following has the smallest radius?

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 34 de 55

1

The Schwarzchild radius of a black hole is:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 35 de 55

1

Harlow Shapley:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 36 de 55

1

Henrietta Leavitt:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 37 de 55

1

The diameter of the disk of the Milky Way is approximately:

Selecciona una de las siguientes respuestas posibles:

  • 300 A.U.

  • 10 light years.

  • 100 thousand light years.

  • a billion light years.

  • a billion billion light years.

Explicación

Pregunta 38 de 55

1

Where in the Milky Way are Type II supernovae usually located?

Selecciona una de las siguientes respuestas posibles:

  • only in the disk.

  • only in the halo.

  • only at the very center.

  • only in the bulge.

  • in the disk, halo, and bulge.

Explicación

Pregunta 39 de 55

1

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:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 40 de 55

1

Synchrotron radiation is produced by:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 41 de 55

1

Who discovered the period-luminosity relationship for Cepheid variable stars?

Selecciona una de las siguientes respuestas posibles:

  • Harlow Shapley.

  • Edwin Hubble.

  • Adriaan van Maanen.

  • William Herschel.

  • Henrietta Leavitt.

Explicación

Pregunta 42 de 55

1

Who first measured the distances to globular clusters, and concluded that the Sun was NOT in the center of the Milky Way?

Selecciona una de las siguientes respuestas posibles:

  • Harlow Shapley.

  • Edwin Hubble.

  • Adriaan van Manaan.

  • William Herschel.

  • Henrietta Leavitt.

Explicación

Pregunta 43 de 55

1

Which of the following objects are NOT generally found in the bulge of the Milky Way, but only in the disk?

Selecciona una de las siguientes respuestas posibles:

  • planetary nebulae.

  • open clusters.

  • white dwarfs.

  • Supernovae Type I.

  • globular clusters.

Explicación

Pregunta 44 de 55

1

Sagittarius A* is:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 45 de 55

1

A black hole is:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 46 de 55

1

When a charged particle is accelerated, it produces light. This kind of light is called:

Selecciona una de las siguientes respuestas posibles:

  • Heat radiation.

  • Thermal radiation.

  • Synchrotron radiation.

  • Magnetic radiation.

  • RR radiation.

Explicación

Pregunta 47 de 55

1

What provided the first evidence of the existence of large quantities of dark matter in the Universe?

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 48 de 55

1

An RR Lyrae star is:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 49 de 55

1

The radius of the event horizon of a black hole is called the:

Selecciona una de las siguientes respuestas posibles:

  • Shapley radius.

  • Synchrotron radius.

  • Pauli radius.

  • Schwarzchild radius.

  • Wormhole radius.

Explicación

Pregunta 50 de 55

1

What phenomenon was observed during the 1919 total solar eclipse?

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 51 de 55

1

How far is the Sun from the center of the Milky Way?

Selecciona una de las siguientes respuestas posibles:

  • 8 light years.

  • 8 parsecs.

  • 8 kiloparsecs.

  • 8 A.U.

  • the Sun is at the center of the Milky Way.

Explicación

Pregunta 52 de 55

1

Who made the first map of the Milky Way by using his telescope to count the stars towards many directions in the sky?

Selecciona una de las siguientes respuestas posibles:

  • Harlow Shapley.

  • Edwin Hubble.

  • Adriaan van Maanen.

  • William Herschel.

  • Henrietta Leavitt.

Explicación

Pregunta 53 de 55

1

On the H-R diagram, Cepheids variables lie:

Selecciona una de las siguientes respuestas posibles:

  • 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.

Explicación

Pregunta 54 de 55

1

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?

Selecciona una de las siguientes respuestas posibles:

  • HII regions.

  • Molecular clouds.

  • Open clusters.

  • Globular clusters.

  • O and B stars.

Explicación

Pregunta 55 de 55

1

The first person to find evidence that the Sun is not in the center of the Milky Way was:

Selecciona una de las siguientes respuestas posibles:

  • Henrietta Leavitt.

  • Harlow Shapley.

  • Edwin Hubble.

  • William Herschel.

  • Robert Trumpler.

Explicación