How can we help?

You can also find more resources in our Help Center.

32 terms

Astronomy

STUDY
PLAY
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.
elipse
on oval shaped path
rotation
the act of rotating as if on an axis
revolution
the movement of an object around another object
au
a unit of length used for distances within the solar system
orbit
the (usually elliptical) path described by one celestial body in its revolution about another
inertia
the tendency of an object to resist any change in its motion
aphelion
orbital point farthest from the sun
perihelion
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
luminosity
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
parsec
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
frequency
the number of occurrences within a given time period (usually 1 second)
wavelength
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
infrared
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
microwaves
Radio waves with the shortest wavelengths and the highest frequencies

Flickr Creative Commons Images

Some images used in this set are licensed under the Creative Commons through Flickr.com.
Click to see the original works with their full license.