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Galaxy is a complete star system composed of billions of stars. NGC 891 has a distinct S shape viewed through 8 inch or larger telescopes. Symbol: Hollow oval; solid oval for extremely bright galaxy; solid oval with arms for spiral galaxy |
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Planetary Nebula is a large luminous envelope of gas surrounding a hot star. |
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Open Star Cluster is a system of stars of common origin which are mutually bound by gravitational forces. Symbol: dotted circle. |
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Visual
binary are stars that can be resolved with a telescope so that two
separate stars can be seen. |
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Eclipsing
binary stars are situated so that one star passes in front ot its
companion thus blocking light from reaching our view at regular
intervals. |
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Optical
doubles is a pair of stars that appear to be close to each other. In
reality one star is more distant than the other and they are not
physically related to one another. |
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Nova
like stars are those who experience brilliant flaring on occasion. |
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Galactic
clusters are clusters of galaxies as viewed from earth and may contain
hundreds to thousands of galaxies. |
