Fw: There's More to the North Star Than Meets the Eye
----- 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
> THERE'S MORE TO THE NORTH STAR THAN MEETS THE EYE
> 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,
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