Probing a dusty theory of star formation.Probing a dusty theory of star formation WUPPE's observations of stars in the Milky Way Milky Way, the galaxy of which the sun and solar system are a part, seen as a broad band of light arching across the night sky from horizon to horizon; if not blocked by the horizon, it would be seen as a circle around the entire sky. helped to verify a theory about stellar dust and star formation proposed 25 years ago by Theodore P. Stecher, an astronomer at NASA's Goddard Space Flight Center The Goddard Space Flight Center (GSFC) is a major NASA space research laboratory established on May 1, 1959 as NASA's first space flight center. GSFC employs approximately 10,000 civil servants and contractors, and is located approximately 6.5 miles northeast of Washington, D.C. in Greenbelt, Md., and principal investigator for Astro's Ultraviolet Imaging Telescope. Using ultraviolet radiation from the supergiant star Alpha Camelopardalis like a flashlight from afar, WUPPE WUPPE Wisconsin Ultraviolet Photopolarimeter Experiment (space) researchers found that certain wavelengths of ultraviolet light Ultraviolet light A portion of the light spectrum not visible to the eye. Two bands of the UV spectrum, UVA and UVB, are used to treat psoriasis and other skin diseases. that pass through interstellar in·ter·stel·lar adj. Between or among the stars: interstellar gases. interstellar Adjective between or among stars Adj. 1. dust have little or no polarization -- a strong indication that the dust absorbs light rather than scatters the radiation, says Arthur D. Code of the University of Wisconsin-Madison “University of Wisconsin” redirects here. For other uses, see University of Wisconsin (disambiguation). A public, land-grant institution, UW-Madison offers a wide spectrum of liberal arts studies, professional programs, and student activities. . Absorption leaves light unpolarized, while scattering creates polarization, he notes. The finding, he adds, indicates that some interstellar dust may act as a vital cooling agent, absorbing ultraviolet energy released when massive gas and dust clouds collapse -- a process believed to give birth to stars. If the interstellar dust could not absorb enough heat, the increase in temperature would halt the collapse before new stars formed, says Code, leader of the WUPPE team. The WUPPE observations support Stecher's 1965 suggestion that interstellar dust contains graphite -- a compound that absorbs ultraviolet light and could act as a cosmic coolant coolant (kōō´l  nt),n . Stecher had sought to explain the results of his sounding rocket experiments, which demonstrated ultraviolet light below a certain wavelength became extinct as it traveled through the interstellar medium. Laboratory experiments showed that graphite in the interstellar dust could explain the missing ultraviolet wavelengths. But some researchers argued that the interstellar medium reflects ultraviolet light and could not contain much of the carbon compound. WUPPE's results -- some of the first data on polarization in the ultraviolet -- provide evidence that the interstellar medium contains a significant amount of graphite, Stecher says. |
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