News Release

Astronomers Take Unusual Ultraviolet Image Of Orion

Peer-Reviewed Publication

Johns Hopkins University

Astronomers at The Johns Hopkins University, using a revolutionary satellite, have taken an unusual image of the constellation Orion that may offer new insights about a bright region where new stars are forming.

Findings from the research will be detailed in a paper to be presented on June 9, during a meeting of the American Astronomical Society. The paper will be on display from 9:20 a.m. to 6:30 p.m. in the South Main Hall of the Benton Convention Center in Winston-Salem. N.C.

It is among the first scientific papers based on observations made with the Midcourse Space Experiment satellite built by the Johns Hopkins Applied Physics Laboratory and launched in April 1996.

MSX is the first satellite capable of taking wide-angle images across the entire spectrum of ultraviolet, infrared and visible light, giving astronomers a more complete view of the sky. By observing the same regions in different wavelengths of light, astronomers hope to learn more about properties of the Milky Way galaxy as well as objects outside the galaxy.

The Orion image is particularly significant because it shows a wide-angle ultraviolet view of dust surrounding a star-forming region known as M42, located about 1,500 light years from Earth.

The hotter an object is the more ultraviolet light it emits. Because hot stars are typically younger, studying the ultraviolet sky teaches scientists more about the properties in regions where stars are born. But the Earth's atmosphere filters out ultraviolet light, so space-borne instruments must be used to make observations in the ultraviolet spectrum.

The research team is led by astrophysicists Richard Henry, a professor in the Johns Hopkins Department of Physics and Astronomy, and Stephan Price, a scientist at the U.S. Air Force's Phillips Laboratory.

"Previous ultraviolet satellites have all had sort of tiny fields of view, so they haven't been able to look at big areas at the same time," said astrophysicist Marsha Allen, a research scientist involved in the work.

"Some of these fields have been observed before, but with MSX we hope to get a complete survey of the sky in both the ultraviolet and the visible," said Jayant Murthy, another research scientist involved in the work.

Also involved in the research were Johns Hopkins graduate students Andrew Dring and Ryan Newcomer and post-doctoral fellow Julian Daniels.

MSX may enable astronomers to learn more about the cycle of star birth, death and rebirth taking place within the same regions of space, Newcomer said. When stars explode, they release the raw materials for the formation of new stars and heavy elements essential for the creation of planets.

MSX also will enable astronomers to compare the way galaxies look today with how they looked billions of years ago, Dring said.

The research has been funded by the Ballistic Missile Defense Organization. MSX, operated by the Applied Physics Laboratory, is used by the military to test space technology designed to identify and track ballistic missiles during the "midcourse" phase of flight, or the portion of flight after the rocket booster burns out and before the missile reenters the atmosphere. But MSX's imaging capabilities are being used for many other non- military projects, including astronomy research.

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