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140 Cards in this Set
- Front
- Back
You note that a particular star is directly overhead. It will be directly overhead again in |
23 hours 56 minutes. |
|
In general, what is true of the alpha star in a constellation? |
It is the brightest star in the constellation. |
|
What celestial line is a product of the Earth's orbit around the Sun? |
Ecliptic |
|
Modern scientific theories are NOT: |
perfect. |
|
If new Moon fell on March 2nd, what is the Moon's phase on March 14th? |
waxing gibbous |
|
Into how many constellations is the celestial sphere divided? |
88 |
|
Some type of solar eclipse will happen about: |
about every six months at new moon. |
|
Where would you be if the Sun sets for six continuous months, beginning on September 23rd? |
North Pole |
|
Which statement about the length of a day is FALSE? |
The sidereal day includes both the Earth's rotation and revolution around the Sun |
|
Which of the choices below correctly lists things in order from largest to smallest? |
Universe, Local Group, Milky Way, Solar System |
|
Which statement about the first quarter moon is FALSE? |
From the Earth, it appears 25% sunlit. |
|
The places where the Sun crosses the equator are called the: |
equinoxes |
|
From a location in the United States of America, a star is observed to be rising due East. Where will this star be located 6 hours later? |
High in the southern sky. |
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A lunar eclipse can only happen during a: |
full moon. |
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When the sun rises it is located in the constellation Gemini. When the sun sets later that same day it will be |
in the constellation Gemini. |
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Which statement about the ecliptic is FALSE? |
The Moon can never leave it, but moves twelve times faster than the Sun. |
|
What conditions are necessary for a partial solar eclipse? |
new moon on ecliptic, with us in the penumbral shadow |
|
Which of the following describes parallax? |
It is inversely proportional to the distance to the star. |
|
About how many stars are visible on a clear, dark night with the naked eye alone? |
a few thousand |
|
When the Moon is directly opposite the Sun in the sky, its phase is |
full. |
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The Law of Universal Gravitation was developed by: |
Newton |
|
A fatal flaw with Ptolemy's model is its inability to predict the observed phases of |
Mercury and Venus |
|
According to Kepler's third law, the square of the planet's period in years is: |
proportional to the cube of its semimajor axis in AU |
|
Given that the planet orbiting the nearby star 51 Pegasi is about 20X larger than the Earth, but 400X more massive, on that world you would weigh: |
the same as you do here |
|
The heliocentric model was actually first proposed by: |
Aristarchus |
|
Which of the following was NOT a contribution of Galileo to astronomy? |
The changing appearance of Saturn's rings corresponds to our seasons. |
|
Tycho Brahe's contribution to Kepler's Laws of Planetary Motion were |
his detailed and accurate observations of the planet's position. |
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Kepler's first law worked, where Copernicus' original heliocentric model failed, because Kepler described the orbits as |
elliptical, not circular |
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Which of these observations of Galileo refuted Ptolemy's epicycles? |
the complete cycle of Venus' phases |
|
The place in a planet's orbit that is closest to the Sun is called |
perihelion |
|
The greatest contribution of the Greeks to modern thought was: |
the development of scientific inquiry and model building. |
|
How much stronger is the gravitational pull of the Sun on Earth, at 1 AU, than it is on Saturn at 10 AU? |
100X |
|
Which of the statements below is part of both the Ptolemaic and Copernican models? |
The Moon orbits the Earth once a month |
|
Galileo found the rotation period of the Sun was approximately |
a month |
|
The Ptolemaic model of the universe: |
explained and predicted the motions of the planets with deferents and epicycles |
|
Scientists today do not accept the Ptolemaic model because: |
the work of Tycho and Kepler showed the heliocentric model was more accurate. |
|
A circular orbit would have an eccentricity of |
0
|
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Which of these was NOT a telescopic discovery of Galileo? |
the moons of Saturn |
|
Geosynchronous satellites orbit at about four earth radii, where the earth's gravitational pull is: |
1/16g |
|
Upon which point do Copernicus and Kepler disagree? |
The orbits of the planets are ellipses, with one focus at the Sun. |
|
What does the phenomenon of interference demonstrate? |
the wave nature of light |
|
Electromagnetic radiation |
can behave both as a wave and as a particle. |
|
Which type of radiation can be observed well from Earth's surface? |
visible |
|
Star A and star B have the same temperature, but star A is 5 times bigger than star B. Which statement below is correct? |
Star A and star B have the same color, but star A is brighter. |
|
The two forms of electromagnetic radiation that penetrate the atmosphere best are: |
visible and radio waves. |
|
There are no X-ray telescopes on Earth because |
X-rays don't penetrate Earth's atmosphere |
|
Hot objects with temperatures of 10 million Kelvin give off most of their radiation in which part of the electromagnetic spectrum? |
x-ray |
|
The total energy radiated by a blackbody depends on |
the fourth power of its temperature. |
|
Increasing the temperature of a blackbody by a factor of 3 will increase its energy by a factor of |
81 |
|
If a light source is approaching you at a speed very close to the speed of light, it will appear |
bluer than it is |
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Which statement gives the relationship between the waves in the electric and magnetic fields in an electromagnetic wave? |
They are in phase but perpendicular to each other in space. |
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Star A has a temperature 1/2 that of star B, but star A is 5 times bigger than star B. Which statement below is correct? |
Star A is redder and brighter than star B. |
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If a wave's frequency doubles, its wavelength |
is halved |
|
The Earth's ionosphere partially blocks which form of electromagnetic radiation? |
radio |
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Star A and star B have the same temperature, but different luminosities. What can you infer about these two stars? |
Nothing can be inferred from the information given. |
|
Colors appear different to us because of their photons' different: |
frequencies |
|
To see the Sun's hot corona (a temperature of 1,000,000 K, which part of the electromagnetic spectrum should one observe? |
the x-ray |
|
The light from an object moving tangentially (to your left or right) will exhibit |
no shift |
|
There are no radio telescopes in space because |
radio waves penetrate Earth's atmosphere so there is no need to put one in space |
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What is true of a blackbody? |
Its energy peaks at the wavelength determined by its temperature. |
|
Which of these is the classic continuous spectrum? |
a rainbow |
|
A hydrogen atom consists of an electron and a(n) |
proton. |
|
The Orion Nebula, M-42, is a hot, thin cloud of glowing gas, so its spectrum is: |
a few bright lines against a dark background. |
|
An incandescent light (glowing tungsten filament) produces: |
a continuous spectrum, with the peak giving the temperature of the filament. |
|
If a source of light is approaching us at 3,000 km/sec, then all its waves are |
blue shifted by 1% |
|
The particles which enter into chemical reactions are the atom's: |
electrons |
|
For hydrogen, the transition from the second to the fourth energy level produces |
a blue green absorption line. |
|
Typical stellar spectra appear as: |
a rainbow, but with some dark lines mixed in. |
|
The Fraunhofer lines in the solar spectrum are actually: |
absorption lines due to the thin outer layer above the photosphere. |
|
The particle which adds mass but no charge to the atomic nucleus is the: |
neutron |
|
If the rest wavelength of a certain line is 600 nm., but we observe it at 594 nm, then |
the source is approaching us at 1 % of the speed of light. |
|
The energy required to move an electron in a hydrogen atom from energy level 2 to energy level 3 is |
1.9 eV |
|
In Bohr's model of the atom, electrons |
only make transitions between orbitals of specific energies |
|
Which of the following type of electromagnetic radiation has the lowest energy? |
radio |
|
The classical model of the hydrogen atom that explains its spectral line structure is due to: |
Bohr |
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In the atom, which particles gives the element its identify (atomic number)? |
protons |
|
Which of the following type of electromagnetic radiation has the highest energy? |
x-ray |
|
An emission spectrum can be used to identify a(n) |
atom
|
|
The three laws dealing with the creation of various spectra are due to: |
Kirchhoff. |
|
The observed spectral lines of a star are all shifted towards the red end of the spectrum. Which statement is true? |
This is an example of the Doppler effect |
|
What problem do refractor telescopes have that reflectors don't? |
chromatic aberration |
|
Compared to optical telescopes, radio telescopes are built large because |
radio photons don't carry much energy. |
|
Which of the following greatly improves the angular resolution of radio maps? |
use of interferometers |
|
It is diffraction that limits the ________ of a telescope of a given objective diameter. |
resolution |
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Which of these devices helps correct coma in fast reflectors? |
Schmidt corrector plate |
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Which of the following is currently supplying high resolution X-ray images from space? |
Chandra |
|
In astronomy, an interferometer can be used to |
improve the angular resolution of radio telescopes |
|
Which design has a convex primary mirror and flat secondary mirror, with the eyepiece located on the top side of the telescope tube? |
Newtonian reflector |
|
Radio dishes are large in order to: |
increase their angular resolution and collect the very weak radio photons. |
|
This design combines the radiation from two different telescopes to greatly enhance resolution via computer synthesis. |
interferometer |
|
What is "seeing"? |
a measurement of the image quality due to air stability |
|
Refractor telescopes suffer from this separation of light into its component colors. |
chromatic aberration |
|
A telescope with a 60 mm objective lens collects how many times as much light as does your eye's 6 mm exit pupil? |
100x |
|
One advantage of the Hubble Space telescope over ground based ones is that |
in orbit, it can operate close to its diffraction limit at visible wavelengths. |
|
What is the resolving power of the telescope? |
the ability to distinguish adjacent objects in the sky |
|
Which type of telescope has the simplest light path? |
prime focus reflector |
|
What are two advantages of large scopes over smaller ones? |
Large telescope have more light grasp and better resolution. |
|
Which method of astronomical measurement is the precise measurement of brightness? |
photometry |
|
Green light has a shorter wavelength than orange light. In a 5 inch telescope, green light will |
provide better angular resolution than orange light. |
|
It is diffraction that limits the ________ of a telescope's objective. |
resolution |
|
What is the absolute magnitude of our Sun? |
+4.8 |
|
On the H-R diagram, red supergiants like Betelguese lie |
at the top right. |
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In general, the narrower the spectral line of a star: |
the bigger the star is. |
|
The Hertzsprung-Russell Diagram plots ________ against the spectral type or temperature. |
luminosity or absolute magnitude |
|
What is proper motion? |
It is the annual apparent motion of a star across the sky. |
|
Upon what data do measurements of sizes of eclipsing binaries depend? |
their Doppler shifts and durations of stages of their eclipses |
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If a star has a parallax of 0.05", then its distance in light years is about: |
65 light years |
|
For a star of 10 solar masses, its main sequence life span will be: |
only 1/1000th of the Sun. |
|
Star A and star B both have an apparent magnitude of 7.0, but star A is at a distance of 15 pc and star B is at a distance of 30 pc. Which statement below is correct? |
Star A and star B appear to have the same brightness, but actually star B is brighter than star A. |
|
Which of the following is the most common type of star? |
low mass main sequence |
|
Star A and star B both have an apparent magnitude of 4.0, but star A has an absolute magnitude of 1.0 and star B has an absolute magnitude of 7.0. Which statement below is correct? |
Star A and star B appear to have the same brightness, but actually star A is brighter than star B. |
|
At the distance of Jupiter (6 times further away from the Sun than Earth) the amount of sunlight received per square centimeter different by what factor? |
36 times less |
|
Which type of binary can have their sizes measured directly by photometry? |
eclipsing |
|
If a star appears to move back and forth relative to other stars over a six-month period, this motion is due to the star's |
parallax shift |
|
Stars that have masses similar to the Sun's, and sizes similar to the Earth are |
white dwarfs |
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In a visual binary system with circular orbits, if in 20 years the two stars' position angles have shifted by 30 degrees, the pair's period must be: |
240 years. |
|
About how many stars has Hipparcos given us accurate distance data on? |
a million, those with parallaxes of .005" or larger |
|
Star A and star B both have an absolute magnitude of 2.0, but star A has an apparent magnitude of 5.0 and star B has an apparent magnitude of 7.0. Which statement below is correct? |
Star A appears brighter than star B, but actually star B and star A are the same brightness. |
|
What are the two most important intrinsic properties used to classify stars? |
luminosity and surface temperature |
|
On the H-R diagram, the Sun lies |
about the middle of the main sequence. |
|
What do "forbidden" lines reveal about interstellar space? |
The density or pressure of this gas is much lower than can be produced in a laboratory. |
|
The ________ of light passing through thin dust clouds lets us map the Galaxy's magnetic field. |
polarization |
|
in the Milky Way galaxy, gas and dust are found |
everywhere |
|
What effect does even thin clouds of dust have on light passing through them? |
It dims and reddens the light of all more distant stars. |
|
The most common molecule in a molecular cloud is: |
molecular hydrogen, H2. |
|
What feature of interstellar dust is inferred by the polarization of starlight? |
its shape |
|
Which of the following have not yet been observed in space? |
DNA |
|
What color is a H I region? |
colorless; it emits in the radio region |
|
The relative density of dust to gas is least in which place? |
the atmosphere of Earth |
|
Charles Messier mapped the night sky and identified many objects now known to be emission nebulae in his search for objects that might be confused with |
COMETS |
|
A large gas cloud in the interstellar medium that contains several type O and B stars would appear to us as |
an emission nebula. |
|
Due to absorption of shorter wavelengths by interstellar dust clouds, distant stars appear |
redder. |
|
The overall dimming of starlight by interstellar matter is called |
extinction. |
|
Which statement about the dark nebulae is true? |
They can be penetrated only with longer wavelengths such as radio and infrared. |
|
Why is 21-cm radiation so important to the study of interstellar matter and the Galaxy? |
Emitted by hydrogen, it passes through interstellar dust and lets us to map the entire Galaxy. |
|
A reflection nebula is caused by |
starlight scattered by dust particles. |
|
Interstellar dust clouds are best observed at what wavelength? |
Radio and infrared |
|
Which is the least dense? |
interstellar dust |
|
The average temperature of the typical dark dust cloud is about |
100k |
|
Emission nebulae like M42 occur only near stars that emit large amounts of |
ultraviolet radiation. |