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Intro to the Universe
Test 1
57
Astronomy
Undergraduate 1
09/24/2012

Additional Astronomy Flashcards

 


 

Cards

Term
Universe
Definition
Anything that can be detected with a telescope
Term
Conjunction
Definition
Two planets side by side
Term
Circumstellar Stars
Definition
Simple time exposure reveals earth's rotation about the northern celestial pole
Term
Distance between the earth and the sun:
Definition
93 million miles
Term
A light year is defined as:
Definition
The distance light travels in one year
Term
A light year equals   ?   miles
Definition
Six Trillion
Term
Classes of Objects in Universe:
Definition
Planets→Brown Dwarfs→Stars→Star Clusters→ Galaxies→Clusters of Galaxies
Term
The overhead point is called...
Definition
Zenith
Term
The imaginary line from due south to due north is the...
Definition
Meridian
Term
Magnitude:
Definition
  • Measures Brightness
  • 1st mag=brightest, 6th mag=dimmest
Term
Apparent Magnitude:
Definition
The way we see stars from earth
Term
Absolute Magnitude:
Definition
The way a star would look if it were at 10 parsecs (3 light yrs)
Term
What factors is brightness determined by?
Definition
Size, Distance, and Temperature
Term
What property of earth gives us the seasons?
Definition
Earth's Tilt
Term
T/F: The Sun is lower in the sky during winter
Definition
True
Term
T/F: The Sun is lower in the sky during Summer
Definition
False, the Sun is higher in the sky during Summer
Term
Rotational Motion:
Definition

(Diurnal)

Rising and setting of the Sun and Moon.

Earth spinning on its axis

Term
Orbital Motion:
Definition

(Annual)

365.25 days

 

Earth's motion around the sun

Term
Precession:
Definition

Planet wobbles on its axis

NCP points to different spots

Term
Copernican Principle:
Definition

 We are not unique or at any special advantage with our position in the universe.

 
Term
Retrograde Motion:
Definition
As Earth passes Mars faster, it looks like Mars is going backward
Term
Galileo's Observations:
Definition
  • Surface topography of the moon
  • Phases of Venus
  • Satellites of Jupiter
  • Composition of the Milky Way
  • "Ears" on Saturn
  • Sunspots
Term
Tycho Brahe
Definition
  • Established government funded observatory
  • Collected extensive data on positions of planets
  • Invented the Tychonic System
  • Discovered comets are extraterrestrial
Term
Kepler's Laws:
Definition
  • 1st: Planets orbits ellipses with the sun at one focus
  • 2nd: Planet-Sun line sweeps out equal areas in equal time.
  • 3rd Law: There is a relationship between a planets orbital period(P) and its average distance from the sun (a), P2=a3
Term
Eccentricity:
Definition

A measure of the ellipse

 

Greater the ellipse=more eccentric

Term
Newton's Laws:
Definition
  1.  An object in motion will stay in motion unless acted upon by an external force
  2. F=ma
  3. For every force there is an equal and oppositely directed reactionary force
Term
Newton's Law of Gravitation
Definition
F=Gm1m2/r2
Term
Wavelength+Frequency Definitions:
Definition

λ=the distance between crests of a wave

f= the # of crests/troughs that pass by each second

 

v=fλ

Term
Order of Electromagnetic Spectrum
Definition
Gamma→X-Ray→UV→Visible Light→Infrared→Microwaves→Radiowaves
Term
What is Brightness directly proportional to?
Definition
1/d2
Term
Spectroscopy:
Definition
Learn: Temperature, Composition, Magnetic Field, or whether stars are coming or going
Term
Doppler Effect:
Definition
  1. Redshift: Wavelengths stretched
  2. Blue Shift: Wavelengths compressed(coming towards)
Term
What is the advantage of having a telescope in space?
Definition
Avoid Atmospheric Disruption
Term
Interferometry:
Definition
Take a bunch of telescopes to produce one image
Term
Major types of telescopes:
Definition
Reflector or Refractor
Term
Ancient astronomers divided the sky into regions containing distinct groups of stars called
Definition
Constellations
Term
The Earth’s atmosphere shields us from most kinds of electromagnetic radiation. The exceptions are
Definition
Infrared Radiation+Visible Light
Term
The type of electromagnetic radiation with a wavelength just longer than that of red light is 
Definition
Infrared Radiation
Term
A curved lens or mirror can form an image by bringing light to a
Definition
Focus
Term
The annual path of the Sun through the sky, with respect to the stars is the 
Definition
Ecliptic
Term
When the Moon is lying on a line directly between the Earth and the Sun, close enough to cast a full shadow on the Earth, we have a
Definition
A total solar eclipse
Term
A star that appears brighter to an observer on Earth has a low 
Definition
Apparent Magnitude
Term

                  ?  is given credit for the idea that the Earth is not the center of the solar system

 
Definition
Copernicus
Term
Kepler was the first to show that planets move
Definition
In eliptical orbits around the sun
Term
A discovery Galileo made with his telescope that contradicted Polemy’s ideas was
Definition
The phases of Venus
Term
An object is moving through space. If all forces are removed from the object, then it will
Definition

Continue in a straight line at constant speed

 

Term
The standard means of methodically investigating nature is the
Definition
The scientific method
Term
To explain a set of facts we start with an educated guess called a
Definition
Hypothesis
Term
All kinds of electromagnetic radiation taken together make up the
Definition
Electromagnetic Spectrum
Term
It is often useful to think of light as particles of energy called
Definition
Photons instead of as waves
Term
What is ecliptic? 
Definition
The annual path of the Sun through the sky with respect to the stars
Term
What is the North Celestial Pole? 
Definition

     Looking at the celestial sphere, it is the northern most axis, straight up from Earth, and is encapsulated by the northern meridian

 
Term

    Why did Ptolemy include epicycles in his geocentric theory of the Universe?


Definition
He included epicycles because each planet orbited the circumference of their own epicycle, while still orbiting earth.
Term
List and explain three uses of spectroscopy in astronomy.
Definition

Three uses of spectroscopy are being able to look at the moon and learn more about its phases and topography, to try and get a greater understanding of our galaxy and universe, and to examine different planets such as Venus

  •  Temperature, Spectroscopy, Stars coming or going
Term
Describe the characteristics of science, and give an example of a scientific theory.
Definition
Science is something you have to research, spend time on, and most importantly be able to test and perform experiments on what you’re trying to prove. An example of a scientific theory is the Big Bang Theory. Scientists are still performing tests and experiments to try and understand more about the Big Bang Theory
Term
List Earth’s three primary motions through space. 
Definition
Rotational, Orbital, Precession
Term
Draw the Heliocentric and Geocentric models of the universe.
Definition
Heliocentric: “My very easy method just set up nine planets” (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Plato)
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