Donald Savage Headquarters Washington May 9 2003 Phone 202/358-1547 Kathie Coil Kitt Peak National Observatory Tucson Ariz Phone 520/318-8214 Ray Villard Space Telescope Science Institute Baltimore Phone 410/338-4514 RELEASE 03-162 IRIDESCENT GLORY OF NEARBY PLANETARY NEBULA SHOWCASED In one of the largest and most detailed celestial images ever made the coil-shaped Helix Nebula is being unveiled today in celebration of Astronomy Day Saturday May 10 The composite picture is a seamless blend of ultra-sharp NASA Hubble Space Telescope HST images combined with the wide view of the Mosaic Camera on the National Science Foundation 0.9-meter telescope at Kitt Peak National Observatory part of the National Optical Astronomy Observatory near Tucson Ariz Astronomers at the Space Telescope Science Institute STScI assembled the images into a mosaic The mosaic was blended with a wider photograph taken by the Mosaic Camera The image shows a fine web of filamentary bicycle-spoke features embedded in the colorful red and blue gas ring which is one of the nearest planetary nebulae to Earth Because the nebula is nearby it appears as nearly one-half the diameter of the full moon This required HST astronomers to take several exposures with the Advanced Camera for Surveys to capture most of the Helix HST views were blended with a wider photo taken by the Mosaic Camera The portrait offers a dizzying look down what is actually a trillion mile-long tunnel of glowing gases The fluorescing tube is pointed nearly directly at Earth so it looks more like a bubble than a cylinder A forest of thousands of comet-like filaments embedded along the inner rim of the nebula points back toward the central star which is a small super-hot white dwarf The tentacles formed when a hot stellar wind of gas plowed into colder shells of dust and gas ejected previously by the doomed star Ground-based telescopes have seen these comet like filaments for decades but never before in so much detail The filaments may actually lie in a disk encircling the hot star like a collar The radiant tie-die colors correspond to glowing oxygen blue and hydrogen and nitrogen red Valuable Hubble observing time became available during the November 2002 Leonid meteor storm To protect the HST including its precise mirror controllers turned the aft end into the direction of the meteor stream for about half a day Fortunately the Helix Nebula was almost exactly in the opposite direction of the meteor stream so Hubble used nine orbits to photograph the nebula while it waited out the storm To capture the sprawling nebula Hubble had to take nine separate snapshots Planetary nebulae like the Helix are sculpted late in a star life by a torrential gush of gases escaping from the dying star They have nothing to do with planet formation but got their name because they look like planetary disks when viewed through a small telescope With higher magnification the classic donut-hole in the middle of a planetary nebula can be resolved Based on the nebula distance of 650 light-years its angular size corresponds to a huge ring with a diameter of nearly three light-years That approximately three-quarters of the distance between our sun and the nearest star The Helix Nebula is a popular target of amateur astronomers and can be seen with binoculars as a ghostly greenish cloud in the constellation Aquarius Larger amateur telescopes can resolve the ring-shaped nebula but only the largest ground based telescopes can resolve the radial streaks After careful analysis astronomers concluded the Nebula really isnt a bubble but is a cylinder that happens to be pointed toward Earth Information about the Helix Nebula and images are available on the Internet at http://hubblesite.org/newscenter/2003/11 The Space Telescope Science Institute STScI is operated by the Association of Universities for Research in Astronomy Inc AURA for NASA under contract with the Goddard Space Flight Center Greenbelt Md The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency ESA Kitt Peak National Observatory part of the National Optical Astronomy Observatory is operated by AURA under a cooperative agreement with the National Science Foundation For information about NASA HST or other Space Science projects on the Internet visit http://www.nasa.gov