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50 Cards in this Set

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The average distance from Earth to the sun

1 AU

If the distance to the nearest star is 4.2 light-years, then

the light we see left the star 4.2 years ago

If light takes 8 minutes to travel from the sun to Earth and over 4 hours to travel from the sun to the planet Neptune, what is the distance from the sun to Neptune?

30 AU

The apparent visual magnitude of a star is 7.3. This tells us that the star is

not visible with the unaided eye

A totally eclipsed moon glows coppery red because

only red light is able to pass completely through Earth's atmosphere and reach the moon

If the north celestial pole appears on your horizon, what is your latitude?

The ______ is 18 years and 11 1/3 days long.

saros cycle

Northern Hemisphere winters are colder than Northern Hemisphere summers because

c and d

A waxing crescent moon is visible

near the western horizon just after sunset.

The diagram below shows three approximate locations of the sun along the western horizon. Which number indicates the location of the sun at sunset on June 21 for an observer at a latitude of 37º N?

3

Parallax is

the apparent motion of an object due to the motion of the observer

Newton concluded that a force from the Earth had to act on the moon because

a force is needed to accelerate the moon toward Earth away from straight-line motion.

Kepler's second law implies that

a planet should move at its greatest speed when it is closest to the sun.

The purpose of using epicycles to explain the motion of the planets in the night sky was to account for

retrograde motion

The greatest inaccuracy in Copernicus' model of the solar system was that the planets

travel in circular orbits with uniform motion.

Ultraviolet radiation from a star

will not penetrate Earth's atmosphere and reach the ground.

The energy of a photon

is inversely proportional to the wavelength of the light.

Which of the following types of electromagnetic radiation has the highest frequency

gamma-rays

The technique of connecting multiple telescopes together to combine the images from each telescope is known as

interferometry.

Which of the following types of electromagnetic radiation has the smallest frequency?

radio

Radio telescopes are _____ telescopes.

Reflecting

Which has the larger light-gathering power?

A telescope of 6 cm diameter and focal length of 100 cm.

The resolving power of a telescope is ____.

a measure of the minimum angular separation that can be seen with the telescope.

In the diagram, which of the transitions would absorb a photon with the smallest energy (longest wavelength)?

Transition 5

The diagram illustrates a light source, a gas cloud, and three different lines of sight. Along which line of sight would an observer see an absorption spectrum?

3

____ has a negative charge and a mass about 1800 times small than a proton.

An electron

Which of the following can be determined by using the Doppler Effect?


I. The speed at which a star is moving away from an observer.


II. The traverse velocity of a star.


III. The radical velocity of a star.


IV. The speed at which a car is traveling toward an observer.

I, III, & IV

Which of the following cannot be determined from the spectrum of a star?

Tangential (perpendicular to line of sight) velocity?

The sunspot cycle affects ____.


I. the latitude at which most sunspots occur


II. the number of sunspots that are visible.


II. The rotation rate of the sun's equator.


IV. the magnetic polarity of the sunspot pair members in a hemisphere.

I, II, & IV [5th one]

The sun's magnetic field is evident in the looped shapes of

prominences

A star's luminosity depends on

temperature and diameter

Interstellar gas clouds may collapse to from stars if they

encounter a shock wave.

The lowest mass object that can initiate thermonuclear fusion of hydrogen has a mass of about

0.08 solar masses

What characteristic of a star primarily its location on the main sequence

mass

____ is a form electromagnetic radiation produced by rapidly moving spiraling through magnetic fields.

Synchroton radiation

Stars in a star cluster

a and b above. (all have the same age and all have the same chemical composition)

After what evolutionary stage does a star become a white dwarf?

Giant

The _____ of a black hole is the radius from a black hole at which the escape velocity is approximately equal to the speed of light.

event horizon

A neutron star is expected to spin rapidly because

they conserved angular momentum when they collapsed.

The absorption lines in the visible portion of the spectrum of a star that are produced by hydrogen are from the

Balmer series

If you move an electron in an atom from a low energy level to a higher energy level within the atom, we say that the atom is

an excited atom.

Each element has its own set of characteristic absorption lines because

electron energy levels differ for each element

Granulation is caused by

rising and sink gases below the photosphere.

The ___ coincides with the period known as the "little ice age" of Europe and North America. This provides one piece of evidence that suggests a link between solar activity and the amount of solar energy Earth receives.

Maunder sunspot minimum.

___ is (are) produced by atomic transitions in the presence of a strong field.

The Zeeman effect

What causes the outward gas pressure that balances the inward pull of gravity in a main sequence star?

c and d (the high temperature of the gas & the high density of the gas)

In the proton-proton chain

energy is produced in the form of gamma rays and the velocity of the created nuclei.

Why do higher mass stars live shorter lives on the main sequence than lower mass stars?

Higher mass stars burn through than nuclear fuel faster.

The Chandrasekhar limit tells us that

white dwarfs more massive than 1.4 solar masses are not stable.

A type-II supernova

c and d (is characterized by a spectrum that shows hydrogen lines & occurs when the iron core of a massive star collapses)