Mas nebulosas planetárias representam uma fase muito breve da evolução estelar, Quando a estrela central da nebulosa encolhe suas camadas exteriores para transformar-se numa quente anã branca. Na verdade, nebulosas planetárias duram apenas entre 10 mil e 20 mil anos. Em consequência, a realmente antiga MWP1 oferece um belo desafio para astrônomos que estudam a evolução de sua estrela central.
The lovely, symmetric planetary nebula cataloged as MWP1 lies some 4,500 light-years away in the northern constellation Cygnus the Swan. One of the largest planetary nebulae known, it spans about 15 light-years. Based on its expansion rate the nebula has an age of 150 thousand years, a cosmic blink of an eye in the 10 billion year life of a sun-like star.
But planetary nebulae represent a very brief final phase in stellar evolution, as the nebula's central star shrugs off its outer layers to become a hot white dwarf. In fact, planetary nebulae ordinarily only last for 10 to 20 thousand years. As a result, truly ancient MWP1 offers a beautiful challenge to astronomers studying the evolution of its central star.
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