A is a star which flares up to hundreds of millions

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A ______________ is a star which flares up to hundreds of millions of times its former brightness. Explanation: Supernova. In contrast to an ordinary nova which increases in luminosity a few thousands or tens of thousands of times, a supernova is much more spectacular. All supernovae rise to maximum light extremely quickly and then usually fade from telescopic visibility within a few months or years after their outburst. Vast clouds of gas and tiny solid particles can be found throughout regions of space and are referred to as "clouds" or interstellar ___________. Explanation: Dust. Tiny solid grains of this dust surrounded by gas are manifested in the following ways: dark nebulae; general obscuration; reddening of starlight; reflection of starlight; and polarization of starlight. The opaque clouds that are conspicuous on any photograph of the Milky Way consist of dense clouds of the solid grains of dust and produce the ________ _____________. Explanation: Dark Nebulae. These areas of gas and dust can extend over vast regions and absorb or scatter a considerable portion of the starlight passing through them. These dark nebulae greatly dim or completely obscure the light of stars behind them. Even where dark clouds are not apparent, some absorption of starlight occurs because of gas and dust causing a general ________________. : Obscuration. This occurs in areas where the distribution of the interstellar dust is spotty and is thinly scattered throughout. This kind of obscurance has interfered with the calculation of the distance of stars. The ______________ of starlight by interstellar dust not only shows that the stars are dimmed, but also provides a means of estimating the amount of obscuration they have suffered. Explanation: Reddening. It is possible to estimate the total amount by which a star is dimmed from the amount that it is reddened. The reddening of the light from a star increases its apparent color index and changes the calculation of the distance of the star. Interstellar dust has a very high ________________ power, much like that of snow. Explanation: Reflecting. Tiny interstellar grains actually absorb some of the starlight they intercept, but most of it is scattered. The scattered or reflected light illuminates the dust itself.
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Molecules of gas scatter light and ______________ it at the same time. Explanation: Polarize. Dust particles of interstellar space also polarize light, but not as much. To polarize light means to cause it to vibrate in a particular direction or path. A star ____________ is a congregation of stars that have a stronger gravitational attraction for each other than do stars of the general field. Explanation: Cluster. Clusters range from rich aggregates of many thousands of stars to loose associations of only a few stars. The mutual gravitation of the stars in the larger clusters may hold them together more or less permanently; the
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A is a star which flares up to hundreds of millions of...

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