ASTR 101 FINAL :D

We win this one frfr :) <3

A disadvantage of the Equatorial Coordinate system is that a stars coordinates change regularly

True

Retrograde motion is caused by relative motion between Earth and the planets outside its orbit

True

Newton’s 2nd law can be used to derive Kepler’s 3rd law if a circular orbit is assumed

True

The seasons are driven by the proximity of Earth to the Sun due to its elliptical orbit

False

All planets have circular orbits

False

Kepler understood what drove the law’s he derived from the orbit of Mars

False

Kepler’s Second Law is a consequence of conservation of angular momentum

True

Adaptive optics allow the observer to correct the mirror in real time

True

An object moving toward you would have the blackbody peak shifted to shorter wavelengths

True

It is easier to make a mirror than a lens

True

As an object gets hotter and hotter it becomes more and more red and bright

False

A single atom produces only one spectral line

False

The terrestrial planets typically have no or small moons.

True

Jupiter radiates more energy than it receives from the Sun

True

Uranus has no indications of interactions with other bodies.

False

The Earth's Moon is a captured body with a different composition

False

The planets all rotate in the same direction due to conservation of angular momentum

False

Copernicus proposed and Galileo proved the _________ model

heliocentric

The ___________ coordinate system locates stars with a right ascension and declination

Equitorial

The location at the _________ of the Horizontal Coordinate system is the zenith

top

An eccentricity of 0 yields a ________

circle

By measuring the ___________________ we can use Wein’s Law to deduce the temperature of a star

spectral peak

Differentiation between the planets is driven by differences in the chemical composition due to the primordial solar system _______ from the outside in

cooling

________ and Earth are similar in elemental composition but different in the chemical combinations

Venus

We can use the difference in the doppler shift to measure the __________ rate of planets

rotation

One of the primary issues with sending probes to the outer planets is the amount of delta-v, fuel, or _______ required to reach them

time

The surface of the sun is homogenous except for sun spots

False

Sun spots are created by the differential rotation leading to areas isolated by distortions in the magnetic field

True

The sunlight that we see is directly generated by the fusion in the core of the Sun

False

The sun is made up of mostly Hydrogen

True

Fusion releases energy by creating elements with a higher binding energy per nucleon

True

Fusion is the process of combining protons into heavier nuclei, neutrinos, electrons, and

energy

The convection zone is an area where the ________ energy from fusion is absorbed by the inner most boundary and transferred to the outer most boundary by a difference in the temperature of the material

thermal

In the model of the Sun the inner most layer is a relatively inactive region where waste ________ collects displacing fusing hydrogen

helium

Variable stars are stars whose mass varies with time

False

After geometric arguments all means of measuring distances rely on finding the absolute brightness of the object and comparing to the observed brightness.

True

The classification of stars was originally done by temperature

False

If all stars are plotted based on color/temperature and brightness there are no patterns

False

The apparent magnitude of the sun is ~-30

True

A _______ is the distance associated with a parallax angle of 1 arc second and base line of 1 Astronomical Unit

Parsec

A __________ is distance light travels in one year

lightyear

The 21 cm line of hydrogen comes from the interaction between the magnetic fields of the proton and orbiting electron

True

An absorption nebula comes from cold matter emitting light at specific wavelengths

False

As mass increases the timescale of formation shortens

True

We detect many different molecules in gas clouds

True

Though thought of as empty space contains very thinly dispersed matter

True

We can detect exoplanets by the oscillations in the spectra of the stars they orbit or their _____________ in front of the star obscuring the light

Transit

As a star forms the formation ends at a line on the H-R Diagram called the _______ sequence

main

As the temperature of a star increases it will emit energy by forming ______ of material in the T Tauri Phase

jets

_______ are regions of gas and dust that can also contain stars

nebulas

A stellar cluster can be aged based on where the stars turn off of the main sequence

true

A Type I supernova is distinguished from a Type II supernova by the presence of hydrogen lines in the Type I supernova

False

Proton-proton fusion stops being able to support a star due to expansion of the Helium Core

True

A Type II supernova results in a neutron star

True

The fate of a star can be determined by the initial mass of the star

true

A white dwarf is an object made up of compressed matter supported by the _________ orbitals in the atoms it is made up of

electron

he Chandrasekhar mass is the mass at which the ____________ from the electron orbitals can no longer support the gravitational pressure and depends on the composition of the object

pressure

A type Ia supernova has an absolute magnitude of -19.5. The sun has an apparent magnitude of -26.74. How far away must an observer be from a type Ia supernova for it to have an apparent magnitude equal to the suns apparent magnitude in pc?

.3565

Once a star turns off of the ________________ it becomes a Red Giant and could creates elements up to iron

main sequence

Fusion is the process of combining protons into heavier nuclei, neutrons, electrons, and _________.

Energy

The convection zone is an area where the __________ energy from fusion is absorbed by the inner most boundary and transferred to the outer most boundary by a difference in the temperature of the material.

Thermal

In the model of the Sun the inner most layer is a relatively inactive region where waste ________ collects displacing fusing hydrogen.

Helium

A _______ is the distance associated with a parallax angle of 1 arc second and base line of 1 Astronomical Unit

Parsec

A _____________ is distance light travels in one year.

Lightyear

We can detect exoplanets by the oscillations in the spectra of the stars they orbit or their _______ in front of the star obscuring the light

Transit

As a star forms the formation ends at a line on the H-R Diagram called the ______ sequence.

Main

As the temperature of a star increases it will emit energy by forming _____ of material in the T Tauri Phase

Jets

______ are regions of gas and dust that can also contain stars

Nebulas

Once a star turns off the ________ it becomes a Red Giant and could create elements up to iron

Main sequence

A white dwarf is an object made up of compressed matter supported by the ____________ orbitals in the atoms it is made up of

Electron

The Chandrasekhar mass is the mass at which the ___________ from the electron orbitals can no longer support the gravitational pressure and depends on the composition of the object.

Pressure

The light from the East limb (edge) of the Sun is blue shifted and the light from the West limb is redshifted. This is because ____________.

The Sun is rotating. One edge is a “source moving towards” us and the other edge is a “source moving away” from us

Sunspots appear dark because they are _________________.

A bit cooler, this dimmer than the rest of the photosphere

Tremendous pressure is created at the Sun’s center due to its own gravity. The Sun is kept from collapsing by ____________.

Gas pressure created by the heat of nuclear fusion

The proton-proton cycle involves what kind of fusion process?

Hydrogen (H) into Helium (He) in the P-P cycle

For two stars of the same apparent brightness, the star closer to the Sun will generally have:

A lower luminosity (Luminosity-absolute brightness- is a property of the star. It is a measure of the total power radiated from the star.)

Which of the following do you need to calculate a star’s luminosity?

Apparent brightness and distance to the star

A binary star system:

Is composed by two stars, held together by gravity, is useful to find the mass of the component stars, and is not always visually detectable

What are the two most important intrinsic properties for classifying stars?

Luminosity and surface temperature

How many radians in 60 degrees

1.0472 radians

If the parallax of a star is measured to be 0.1 seconds of arc, its distance is:

10 parsecs

Interstellar gas is composed primarily by:

90% Hydrogen, 9% Helium, and 1% heavier elements

The reddish color of emission nebulae indicates that:

Hydrogen gas is present

If an interstellar cloud contracts to become a star, it is due to which force?

Gravitational

Objects more massive than the sun form into stars:

Much faster, over tens of thousands of years (more mass=faster collapse, more mass= faster start of fusion reactions, more mass= a hotter, more luminous main sequence star)

What is a T-Tauri star?

A protostar about to become a star (T-Tauri stars often show jets of gas emitted in two directions — “bipolar flow” — suggesting they are not yet stable)

During formation, the Sun evolved TOWARD the main sequence as shown in the figure. The Sun will evolve AWAY from the main sequence when:

Helium builds up in the core, while the hydrogen-burning shell expands (when the Sun’s core becomes unstable and contracts, additional H fusion generates extra pressure, and the star will swell into a RED GIANT)

Stars like our Sun will end their lives as:

White dwarfs

A white dwarf can explode when:

It’s mass exceeds the Chandrasekhar limit (if additional mass from a companion star pushes a white dwarf beyond 1.4 solar masses, it can explode in a Type I supernova

The further away a galaxy is the faster it seems to be moving

True

In addition to stellar evolution we can use the orbits of globular clusters to map the milky way

True

We have no evidence of what is at the center of the galaxy

False

Andromeda is on of the few galaxies with a blueshift

True

Nearly all of the galaxies in the universe seem to be moving toward us creating a blue shift

False

If we analogize our galaxy to a solar system the black hole at the center is the ______, the disk is the planets and the halo is the Oort and Kuiper Belt

Sun

Dark matter is called "dark" because it only interacts with the ____________ force

gravitational

The spiral arms of a spiral galaxy are _________ waves

density

Within 200 Mpc we can correlate the rotation rate of a galaxy to its __________

luminosity

The cosmological principle says that the universe is both homogenous and isotropic

true

We frequently get multiple images of the same galaxy

true