Hubble: first light with a second eye.Hubble: First light with a second eye Two stars in a cluster known as NGC 188 provided "first light" for an image (far right) taken June 17 by the Hubble Space Telescope's most sensitive eye. Astronomers expect the instrument, called the faint-object camera (FOC), to detect stars and other celestial objects as dim as 28th magnitude -- so faint that telescope on Earth cannot detect them at all. NGC 188 is 630 times brighter than that, says F. Duccio Macchetto of the European Space Agency European Space Agency (ESA), multinational agency dedicated to the promotion, for exclusively peaceful purposes, of cooperation among European states in space research and technology. in Paris and the Space Telescope Science Institute The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope (HST; in orbit since 1990) and for the James Webb Space Telescope (JWST; scheduled to be launched in 2013). at Johns Hopkins University Johns Hopkins University, mainly at Baltimore, Md. Johns Hopkins in 1867 had a group of his associates incorporated as the trustees of a university and a hospital, endowing each with $3.5 million. Daniel C. in Baltimore. To prevent an overexposure overexposure too long an exposure time or too high a milliamperage causing too black a picture, loss of detail and some anomalies of translucency. , engineers, had to use filters to cut the instrument's sensitivity by about seven magnitudes. The FOC has such a small field of view that "the whole team ... broke out the champagne when we saw the very stars we had expected to see in the FOC image," Macchetto says. The image on the left shows that far more distorted appearance of the same two stars as viewed from the ground through the turbulence of Earth's atmosphere. Astronomers took this photo using the 2.5-meter Nordic Optical Telescope The Nordic Optical Telescope (NOT) is an astronomical telescope located at Roque de los Muchachos Observatory, La Palma in the Canary Islands. First light came in 1988, with regular observing beginning in 1989. It is funded by Denmark, Sweden, Iceland, Norway and Finland. on the Canary Island of La Palma. The two stars -- imaged as engineers worked to sharpen the Hubble's focus and to reduce the vibrations affecting it -- were chosen because astronomers had accurate information on the positions and brightnesses of stars in their cluster. NGC 188, a part of the Milky Way galaxy Milky Way Galaxy Large spiral galaxy (roughly 150,000 light-years in diameter) that contains Earth's solar system. It includes the multitude of stars whose light is seen as the Milky Way, the irregular luminous band that encircles the sky defining the plane of the galactic , is about 5,000 light-years from Earth and located about 4[degrees] from the position of the North Star. Astronomers estimate its age at about 12 billion years, nearly that of the Milky Way galaxy. The space telescope's other imaging instrument, called the wide-field and planetary camera, saw its "first light" on May 20 (SN:5/26/90, p.325). |
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