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keplers 1st law of planetary motion

gives the idea that a planet goes around the sun on an ellipse with the sun at one focus of the ellipse

Keplers 2nd law of planetary motion

states that the closer a planet gets to the sun the faster it will go and the line connecting the planet to the sun sweeps out in equal areas in equal intervals of time.

Keplers 3rd law of planetary motion

further a planet is from the sun, the longer it takes for the planet to revolve around the sun.


on oval shaped path


the act of rotating as if on an axis


the movement of an object around another object


a unit of length used for distances within the solar system


the (usually elliptical) path described by one celestial body in its revolution about another


the tendency of an object to resist any change in its motion


orbital point farthest from the sun


orbital point nearest the sun

apparent magnitude

the brightness of a star when viewed from Earth

absolute magnitude

The actual brightness of a star when viewed from earth


how bright a star will be in relation to the sun if all of the stars were the same distance from the person watching

white dwarf

a small, hot, dim star that is the leftover center of an old star

main sequence

a diagonal area on an H-R diagram that includes more than 90 percent of all stars in the solar system

red giant

A star that expands and cools once it runs out of hydrogen fuel

parallax angle

apparently angular shift of a star's position as Earth orbits the sun

doppler shift

change in the apparent frequency of a wave as the observer and source move toward or away from each other


a unit used in astronomy to describe large distances (1=3.26 light years)

light year

the distance that light travels in 1 year

electromagnetic radiation

a form of energy that exhibits wavelike behavior as it travels through space


the number of occurrences within a given time period (usually 1 second)


The distance between crests of waves, such as those of the electromagnetic spectrum.

visible light

Electromagnetic radiation that can be seen with the unaided eye

x rays

wavelengths shorter than ultraviolet rays, but longer than gamma rays

gamma rays

the shortest wavelengths and highest frequencies

radio waves

longest wavelengths and lowest frequencies

ultra violet rays

frequenceies higher than visible light, but lower than x-rays


electromagnetic radiation with wavelengths longer than visible light but shorter than radio waves

cosmic rays

electromagnetic waves, that have particles shot out by a supernova very fast


Radio waves with the shortest wavelengths and the highest frequencies

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