sciencesourceimages:Celestial Headstones A Planetary Nebula marks the end of a star’s life.
sciencesourceimages: Celestial Headstones A Planetary Nebula marks the end of a star’s life. They form when a star uses up all of the hydrogen in its core, an event our Sun will go through in about five billion years. See More Images Of Celestial Nebulae As it’s life draws to a close, the star begins to cool and expand, increasing its radius by tens to hundreds of times its original size. Eventually, the outer layers of the star are carried away by a 50,000 kilometer per hour wind, leaving behind a hot core. This hot core has a surface temperature of about 50,000 degrees Celsius, and is ejecting its outer layers in a much faster wind traveling six million kilometers per hour. The radiation from the hot star and the interaction of its fast wind with the slower wind creates the complex and filamentary shell of a planetary nebula. Eventually the remnant star will collapse to form a white dwarf star, which are found at the center of these nebulae. Planetary nebulae may play a crucial role in the chemical evolution of the Milky Way, returning material to the interstellar medium from stars where elements, such as carbon, nitrogen, oxygen and neon, have been created. Planetary nebulae are also observed in more distant galaxies, yielding useful information about their chemical abundances. Images above courtesy of NASA & ESA Visit our website: www.ScienceSource.com -- source link