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55 Cards in this Set
- Front
- Back
Zenith |
The point in the sky directly above the observer |
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Arc Second |
1/60th of an arc minute |
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Sidereal period |
The period of rotation or revolution of an astronomical body relative to the stars |
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Asterisms |
A named grouping of stars that is not one of the recognized constellations |
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Aphelion |
The orbital point of greatest distance from the sun |
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Flux |
A measure of the flow of energy through a surface, usually applied to light |
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North Celestial Pole |
The points on the celestial sphere directly above Earth's north and south poles |
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Angular Distance |
The angle formed by lines extending from the observer to two locations in the sky |
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Nadir |
The point on the celestial sphere directly below the observer. opposite of the zenith |
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Summer Solstice |
The point on the celestial sphere where the sun is at its most northerly point - also the beginning of summer |
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North Point |
The four cardinal directions, the points on the horizon in those exact directions |
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Precession |
The slow change in orientation of the Earths axis rotation. Once cycle takes nearly 26,000 years. |
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Autumnal Equanox |
The point on the celestial sphere where the sun crosses the celestial equator going southward - also the beginning of autumn |
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Solar Eclipse |
The event that occurs when the moon passes directly between Earth and the sun, blocking your point of view |
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Punumbra |
The portion of shadow that is only partially shaded. |
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Winter Soltice |
The point on the celestial Sphere where the Sun is the farthest south. |
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Saros Cycle |
An 18-year, 11⅓-day period after whichthe pattern of lunar and solar eclipses repeats. |
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Vernal Equanox |
The place on the celestial sphere where the sun crosses the celestial equator moving northward - also the beginning of spring |
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Horizon |
The circular boundary between the sky and Earth |
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Evening Star |
Any planet visible in the sky just after sunlight |
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Synodic Period |
The Period of rotations or revolutions of a celestial body with respect to the sun |
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Arc Minutes |
1/60th of a degree. |
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Magnitude Scale |
The astronomical brightness scale. Thelarger the number, the fainter the star. |
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Annular Eclipse |
A solar eclipse in which the polarphotosphere appears around the edgeof the moon in a right ring, or annulus.Features of the solar atmospherecannot be seen during an annulareclipse. |
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Circumpolar constellations |
Any of the constellations to close so thecelestial poles that they never set (ornever rise) from a given location. |
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Lunar Eclipse |
The darkening of the moon when itmoves through Earth’s shadow. |
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Scientific Model |
A scientific metaphor; a concept thatorganizes thought about an aspect ofnature without necessarily beingliterally true. |
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Revolution |
Orbital motion about a point located outside the orbiting body. |
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Apparent Visual Magnitude (Mv) |
A measure of the brightness of a star as seen by human eyes on earth |
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Umbra |
The region of a shadow that is totally shaded |
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Contellations |
One of the stellar patterns identified by name, usually of mythological gods, people, animals or objects. Also the region of the sky containing that star pattern |
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Celestial equator |
The imaginary line around the sky directly above the earth's equator |
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Morning Star |
Any planet visible in the sky just before sunrise |
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Perihelion |
The orbital point of closest approach to the sun |
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Zodiac |
A band centered on the ecliptic and encircling the sky |
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Rotation |
Motion around an axis passing the the rotating body |
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Celestial Sphere |
An imaginary sphere of very large radius surrounding Earth to which the planets, stars, sun, and moon seem to be attatched |
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Ecliptic |
The apparent path of the sun around the sky |
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Angular Diameter |
The angle formed by lines extending from the observer to opposite edges of an object |
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East Point |
The four cardinal directions; the point on the horizon in those exact directions |
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South Celestial Pole |
The points on the celestial sphere directly above earth's north and south poles |
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South Point |
The four cardinal directions; the points on the horizon in those exact direction |
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West Point |
The four cardinal directions; the points on the horizon in those exact directions
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Apparent Visual Magnitude |
A measure of brightness of a star as seen by human eyes on Earth
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Arc Minute |
1/60th of a degree
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Arc Second |
1/60 of an arc minute
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Asterism |
A named grouping of stars that is not one of the recognized constellations
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Circumpolar Constellation |
Any of the constellations so close to the celestial poles that the never set or never rise from a given location
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Constellation |
One of the stellar patterns identified by name of mythological gods, people, animals, or objects. Also the region of the sky containing that star pattern.
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North and South Celestial Poles |
The points on the celestial sphere directly above Earth's north and south poles |
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New Moon |
A solar eclipse can only be observed when the moon is in this position |
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Zenith |
The point on the celestial sphere directly above an observer who can be at any point on the Earth |
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Magnitude Scale |
Can be used to indicate the apparent intensity of a celestial object |
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The Big Dipper |
Is an asterism |
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Precession |
The apparent motion that the celestial poles and equator slowly move relative to the stars |