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71 Cards in this Set
- Front
- Back
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Constellation |
Patterns of groupings of stars that may resemble objects or animals. |
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Stars of a Constellation |
only appear to be close to one another from our viewpoint |
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Star Lore |
Not a science Stories about constellations |
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88 Modern Constellations |
division of the sky into 88 unequal pieces that make it easier to identify regions in the sky -the Greek alphabet is used to names stars by brightness |
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Celestial Coordinates |
grid system using declination and right ascension |
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Declination |
(like latitude) gives the angle north or south of the celestial equator in degrees |
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Right Ascension |
(like longitude) gives the angle east or west of the prime meridian in hours or minutes. |
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Star Charts |
Example: Planisphere |
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Things to see with the unaided eye |
Positions of the Sun, Phases of the Moon, Constellations, The Milky Way, Meteors and Meteor Showers, Locations of the bright planets: Venus, Jupiter, Mars, Saturn, Mercury, Star clusters: Pleiades, etc., Lunar and Solar eclipses, Comets, Bright galaxies: Andromeda, LMC.... |
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Telescope Functions |
collect more light than your eye due to its large diameter. Magnify the image, record data onto film or imager |
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Types of Telescopes |
Refracting telescope, Reflecting telescope, Cassegrain |
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Refracting Telescope |
uses a large-diameter lens to collect light |
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Reflecting Telescope |
uses a large-diameter mirror to collect light, but requires a second mirror to view the image |
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Cassegrain Design |
uses sophisticated optics to produce a ling focal-length telescope in a compact size |
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Telescope parts |
objective, eyepiece, focus-er, mount, finder scope, stand, optical tube, |
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Objective |
collects light and focuses it to a small image |
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Eyepiece |
magnifies the image for the eye to see |
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Focus er |
changes the position of the eyepiece |
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Mount |
allows the telescope to move |
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Finder Scope |
helps you locate objects |
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Stand |
keeps telescope steady |
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Optical Tube |
holds parts together, blocks straight light, keeps objects clean |
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Light Gathering Power |
how much light the telescope can collect |
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Limiting Magnitude |
the dimmest star observable with telescopes |
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Magnification |
how many times larger the telescope makes an object look *resolution is more important |
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Resolving Power |
measure of the finest detail that can be observed |
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Observatories |
limited by: Transparency, Seeing, Darkness, Cloud Cover |
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Transparency |
how clear the air is |
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Seeing |
how still the air is |
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Darkness |
how much background light there is |
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Cloud Cover |
blocks visible light |
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Non-Visible Electromagnetic Observations |
Radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays |
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Radio Astronomy |
useful for studying black holes, pulsars, quasars, galactic centers, etc. |
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Gold-stone Apple Valley Radio Telescope |
remote access radio telescope |
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Non-visible Observations at other wavelengths |
observation of celestial radiation using infrared, ultraviolet, and x-ray wavelengths |
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Telescopes in Space |
avoids atmospheric effects but extremely expensive |
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Adaptive Optics |
straightens reflection of light to overcome "seeing" |
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Kepler's First Law of Planetary Motion |
each planet moves in an elliptical orbit with the sun at one focus. |
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Kepler's Second Law of Planetary Motion |
Planets move fastest when close to the sun and slowest when furthest from the sun |
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Kepler's Third Law of Planetary Motion |
there's a mathematical relationship between orbital distance and orbital period p2=a3 p=period (given in years) a=distance (given in astronomical units) |
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Physics |
the study of forces and energy |
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mass |
the quantity of matter |
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velocity |
how fast and in what direction something is moving |
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acceleration |
the rate of change of velocity |
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force |
push or pull |
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weight |
downward force due to gravity (different depending where you are) |
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Newton's First Law of Motion |
Inertia: objects continue to move or not move until a force changes that |
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Newton's Second Law |
the relationship between force, mass, and accelaration. F=ma Force=mass x accelaration without air everything falls |
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Newton's Third Law of Motion |
forces can't occur in isolation |
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Newton's Law of Gravitation |
relationship between mass, force, and distance gravity is never zero fg=gm1 x gm2/r2 |
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Centripetal Force |
the force needed to make an object turn in a circle |
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Getting into orbit |
you have to go so fast that the curve of falling matches the curve of the Earth for Earth=17,000 mph 20 times faster than sound |
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Surface Gravity |
determines how much things weigh on the surface of a planet. depends on the mass of a planet and its radius. |
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Escape Velocity |
to completely get away from a planet, it has to travel at the escape velocity Earth=25,000 mph moon= 5400 mph Venus= 23,000 mph Mars= 11,000 mph black hole= speed of light |
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Measuring the mass of a planet |
observe the orbit of the moon of the planet |
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The Earth is Spherical |
because of this the sun, moon, planets, and stars are at different angles depending on viewers latitude. |
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The Earth Spins (rotates on the axis) |
sun, moon, stars, planets appear to rise in the east and set in the west |
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Diurnal Motion |
the apparent motion of the celestial sphere due to the earth's rotation |
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Sidereal Day |
time for the Earth to spin once relative to the stars 23 hours 56 minutes every sidereal day the stars are back in the same spot |
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Solar Day |
time for the sun to move from noon to noon average of 24 hours |
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The Earth Orbits around the Sun |
the earth moves 2au from one side of its orbit to the other allowing us to use parallax to measure the distance to the nearby stars |
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the Earth's spin axis is tipped 23.4 degrees |
seasons |
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The Moon Orbits the Earth |
-lunar phases moon rises and sets 49 minutes later each day |
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the moons orbit is tipped to the ecliptic |
makes eclipses rare |
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Lunar Eclipse |
moon passes through the Earth's shadow takes several hours seen by everyone on the dark side of earth occurs only during a full moon |
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Solar Eclipse |
Moon's shadow passes across the earth's surface seen only a few minutes by ppl in the shadows path only during a new moon |
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The planets all orbit in the same direction |
counterclockwise as seen from the north and in the same plane |
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Retrograde Motion of Mars |
caused by earth passing mars on the inside orbit |
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Mercury and Venus orbit closer to the Earth than the other planets |
can only be seen in the morning and in the evening the rest can be seen anytime on the ecliptic |
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Precession |
star positions slowly rotate in 23 degree circle over 26,000 years direction of the north axis |
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Stars are very far away |
they appear smaller than they are |
