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Fw: There's More to the North Star Than Meets the Eye

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  • Mobydoc
    ... Subject: There s More to the North Star Than Meets the Eye
    Message 1 of 1 , Jan 9, 2006
      ----- Original Message -----
      Subject: There's More to the North Star Than Meets the Eye

      > Jan. 9, 2006
      > Erica Hupp
      > Headquarters, Washington
      > (202) 358-1237
      > Donna Weaver
      > Space Telescope Science Institute, Baltimore
      > (410) 338-4493
      > David Aguilar
      > Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.
      > (617) 495-7462
      > RELEASE: 06-004
      > By stretching the capabilities of NASA's Hubble Space Telescope to the
      > limit, astronomers photographed the close companion to Polaris, known
      > also as the North Star, for the first time.
      > "Hubble's exceptional pointing capabilities combined with the
      > wonderful performance of its instruments allow scientists to see the
      > universe in finer detail than ever before," said Michael Moore,
      > NASA's Hubble program executive. "It is that clear vision that makes
      > these types of images possible," he added.
      > The North Star is thought to be a steady, solitary point of light that
      > guided sailors for ages, but there is more to this star than meets
      > the eye. The North Star is actually a triple star system. While one
      > companion is easily viewed with small telescopes, the other hugs
      > Polaris so tightly that it has never been seen until now.
      > "The star we observed is so close to Polaris that we needed every
      > available bit of Hubble's resolution to see it," said astronomer
      > Nancy Evans of the Harvard-Smithsonian Center for Astrophysics,
      > Cambridge, Mass. The companion proved to be less than two-tenths of
      > an arcsecond from Polaris. That is an incredibly tiny angle
      > equivalent to the apparent diameter of a quarter located 19 miles
      > away. At the system's distance of 430 light-years from Earth, that
      > translates into a separation of about 2 billion miles.
      > "The brightness difference between the two stars made it even more
      > difficult to resolve them," said astronomer Howard Bond of the Space
      > Telescope Science Institute, Baltimore. Polaris is a super-giant more
      > than two thousand times brighter than the sun, while its companion is
      > a dwarf star. "With Hubble, we've pulled the North Star's companion
      > out of the shadows and into the spotlight," he said.
      > "Our ultimate goal is to get the accurate mass for Polaris," Evans
      > said. "To do that, the next milestone is to measure the motion of the
      > companion in its orbit," she added. Astronomers want to determine the
      > mass of Polaris, because it is the nearest Cepheid variable star.
      > Cepheids' brightness variations are used to measure the distances of
      > galaxies and the expansion rate of the universe. It is essential to
      > understand their intrinsic physics makeup and evolution. Knowing
      > their mass is the most important ingredient in this understanding.
      > The researchers plan to continue observing the Polaris system for
      > several years. The movement of the small companion during its 30-year
      > orbit around the primary should be detectable. The researchers
      > presented their data today during the 207th meeting of the American
      > Astronomical Society in Washington.
      > The Hubble Space Telescope is a project of international cooperation
      > between NASA and the European Space Agency. The Space Telescope
      > Science Institute in Baltimore conducts Hubble science operations.
      > The Institute is operated for NASA by the Association of Universities
      > for Research in Astronomy, Inc., Washington.
      > For images and additional information about this research on the Web,
      > visit:
      > http://hubblesite.org/news/2006/02
      > For information about NASA and agency programs on the Web, visit:
      > http://www.nasa.gov/home
      > -end-
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