March 9, 2000: From ground-based telescopes, the glowing gaseous debris surrounding dying, sun-like stars in a nearby galaxy, called the Large Magellanic Cloud, appear as small, shapeless dots of light. But through the "eyes" of NASA's Hubble Space Telescope, these bright dots take on a variety of shapes, from round- to pinwheel-shaped clouds of gas.See the rest:
The six objects in the picture illustrate the assortment of planetary nebulae identified in the galaxy. SMP 16, 30, and 93 are examples of a bipolar nebula, twin lobes of gas projecting away from a dying star. SMP 10 has a pinwheel shape and is known as a "point-symmetric" nebula. SMP 4 has an elliptical appearance, and SMP 27, consisting of four lobes of gas, is called a "quadrupolar" nebula. The lines point to the objects' locations in the Large Magellanic Cloud. A ground-based observatory snapped the picture of this galaxy.
Scientists are probing these illuminated stellar relics in our neighboring galaxy because they are at relatively the same distance - about 168,000 light-years — from Earth. Knowing the distance to these objects allows scientists to compare their shapes and sizes, and precisely determine the brightness of their central stars. For this reason, even though these glowing remains of dying stars are about 50 times farther away than the stunning planetary nebulae photographed in the Milky Way, they are of invaluable importance.
By sampling this population, scientists noticed that the bipolar nebulae are richer in some heavier elements, such as neon, than those with a more spherical shape. At the dawn of the universe, only the lighter elements, such as hydrogen, filled the heavens. The heavier elements were produced later as stars died. Neon, in particular, is produced only when massive stars die in supernova explosions. Thus, a higher abundance of neon in "bipolar" planetary nebulae indicates that the stars that sculpted these objects were born more recently (i.e., in an environment that had suffered more supernova explosions) than those that created the more symmetrically shaped clouds of gas.
Credits for the copyrighted image of the Large Magellanic Cloud: D. Malin, Anglo-Australian Observatory/Royal Observatory, Edinburgh, Scotland