chapter 21 power point stars,galaxies, and the universe
TRANSCRIPT
Chapter 21 power point
• Stars,galaxies, and the universe.
constellation• A pattern of
stars in the sky.
Visible light• Electromagneti
c radiation that can be seen with the unaided eye.
Electromagnetic radiation
• Energy that travels through space in the form of waves.
Wavelength
• The horizontal distance between two wave crests.
Spectrum
• The range of wavelength of electromagnetic waves.
Refracting telescope
• A telescope that uses one or more mirrors to gather and focus light.
Convex lens
• A piece of transparent glass curved so that the middle is thicker than the edge
Reflecting telescope
• A telescope that uses one or more mirrors to gather light.
Radio telescope
• A device used to detect radio waves from objects in space.
Observatory
• A building that contains one or more telescopes.
Spectrographs
• An instrument that separates light into colors and photographs the resulting spectrum.
Galaxy
• A giant structure that contains hundreds of billions of stars.
Universe
• All of space and everything in it.
Light-year
• The distance that light travels in a year.
Parallax
• The apparent change in position of an object when seen from different places.
Giant star
• A very large star much larger than the sun.
Apparent magnitude
• The brightness of a star as seen from earth.
Absolute magnitude
• The brightness of a star as if it were a standard distance from earth.
Hertzsprung-Russell diagram
• A graph relating the temperature and brightness of a star.
Main sequence
• An area on the H-R diagram that runs from the upper left to the lower right and includes more than 90% of all stars.
Pulsar
• A neutron star that produces radio waves
Nebula
• A large amount of gas and dust in space spreaded out in an immense volume
Protostar
• A contracting cloud of gas and dust the earliest stage of a stars life.
White Dwarf
• The remaining hot core of a star after its outer layers have expanded and drifted out into space.
Supernova
• The explosion of a dying giant or supergiant star.
Neutron Star
A tiny star that remains after a supernova explosion.
Black Hole
• The remains of an extremely massive star pulled into a small volume by the force of gravity.
• A distant galaxy with a black hole at its center.
Quasar
Binary Star
• A star system that contains two stars.
Eclipsing Binary
• A star system in which one star periodically blocks light from another.
Spiral Galaxy
• A galaxy whose arms curve outward in a pinwheel pattern
Elliptical Galaxy
• A galaxy shaped like a flattened ball containing only old stars.
Irregular Galaxy
• A galaxy that does not have a regular shape.
Big Bang
• The initial explosion that resulted in the formation and expansion of the universe.
Bibliography
• The science book
• And ->
This power point is by Shanan Nathan Doug