Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Astronomy Part 2
| Term | Definition |
|---|---|
| Photosphere | a sphere of light or radiance |
| Chromospere | a scarlet, gaseous envelope surrounding the sun outside the photosphere, from which enormous quantities of hydrogen and other gases are erupted |
| Corona | a white or colored circle or set of concentric circles of light seen around a luminous body, especially around the sun or moon |
| Solar Wind | an emanation from the sun's corona consisting of a flow of charged particles, mainly electrons and protons, that interacts with the magnetic field of the earth and other planetary bodies |
| Sunspot | one of the relatively dark patches that appear periodically on the surface of the sun and affect terrestrial magnetism and certain other terrestrial phenomena |
| Prominence | an eruption of a flamelike tongue of relatively cool, high-density gas from the solar chromosphere into the corona where it can be seen during a solar eclipse or by observing strong spectral lines in its emission spectrum |
| Solar Flare | to burn with an unsteady, swaying flame, as a torch or candle in the wind |
| Aurora | a radiant emission from the upper atmosphere that occurs sporadically over the middle and high latitudes of both hemispheres in the form of luminous bands |
| Nuclear Fusion | a thermonuclear reaction in which nuclei of light atoms join to form nuclei of heavier atoms, as the combination of deuterium atoms to form helium atoms |
| Constellation | any of various groups of stars to which definite names have been given, as Ursa Major, Ursa Minor, Boötes, Cancer, Orion |
| Binary Star | a system of two stars that revolve about their common center of mass |
| Light-Year | the distance traversed by light in one mean solar year |
| Apparant Magnitude | the magnitude of a star as it appears to an observer on the earth |
| Absolute Magnitude | the magnitude of a star as it would appear to a hypothetical observer at a distance |
| Main-Sequence Star | any star lying on a diagonal band that extends from hot stars of high luminosity to cool stars of low luminosity |
| Red Giant | a star in an intermediate stage of evolution, characterized by a large volume, low surface temperature, and reddish hue |
| Supergiant | an exceptionally luminous star whose diameter is more than 100 times that of the sun, as Betelgeuse or Antares |
| Cepheid Variable | a variable star in which changes in brightness are due to alternate contractions and expansions in volume |
| Nova | a star that suddenly becomes thousands of times brighter and then gradually fades to its original intensity |
| Nebulae | a cloud of interstellar gas and dust |
| Hertzsprung-Russell Diagram | the graph showing the absolute magnitude plotted against the surface temperature for a group of stars |
| Protostar | an early stage in the evolution of a star |
| Supernova | the explosion of a star |
| White Dwarf | a star that has undergone gravitational collapse and is in the final stage of evolution for low-mass stars |
| Neutron Star | an extremely dense, compact star composed primarily of neutrons, especially the collapsed core of a supernova |
| Pulsar | one of several hundred known celestial objects that emit pulses of radiation |
| Black Hole | a theoretical massive object whose gravitational field is so intense that no electromagnetic radiation can escape |
| Galaxy | a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space |
| Hubble's Law | the law that the velocity of recession of distant galaxies from our own is proportional to their distance from us |
| Big Bang Theory | a theory that deduces a cataclysmic birth of the universe (big bang) from the observed expansion of the universe, cosmic background radiation, abundance of the elements, and the laws of physics |
Created by:
3161979
Popular Earth Science sets