A flare for pondering Halley's outburst.Two astronomers Famous astronomers and astrophysicists include: Directory: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A
Sudden intense brightening of a small part of the Sun's surface, often near a sunspot group. Flares develop in a few minutes and may last several hours, releasing intense X rays and streams of energetic particles. may have triggered Comet Halley's brief and unexpected outburst, first observed last February (SN: 3/2/91, p.133). The comet, normally a quiescent quiescent at rest; latent; the G0 stage of the cell cycle. body of ice and dust as it exists the solar spotlight, suddenly appeared 300 times as bright as predicted some 2 million kilometers from the sun. The researchers suggest that heightened solar activity just before and during the outburst may account fo Halley's brightening. A shock wave generated by a solar flare may have damaged the comet's fluffy ice crust, and the kick from a second may have cracked open part of the crust, releasing a pocket of gas from within the comet. The expelled gas could have dragged out enough dust -- which reflects sunlight well -- to account for the brightening. Devrie S. Intriligator of the Carmel Research Center in Santa Monica Santa Monica (săn`tə mŏn`ĭkə), city (1990 pop. 86,905), Los Angeles co., S Calif., on Santa Monica Bay; inc. 1886. Tourism and retailing are important, and the city has motion-picture, biotechnology, and software industries. , Calif., and Murray Dryer of the National Oceanic and Atmospheric Administration Noun 1. National Oceanic and Atmospheric Administration - an agency in the Department of Commerce that maps the oceans and conserves their living resources; predicts changes to the earth's environment; provides weather reports and forecasts floods and hurricanes and in Boulder, Colo., present their proposal in the Oct. 3 NATURE. |
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