Preliminary results of a surveyof neighboring galaxies reveals a higher number of young, massive stars thanwas expected.

New photos of some of the MilkyWay's closest neighbors are among the most comprehensive and detailed ever.Importantly, the photos use various filtering techniques to separate stars thatwere visually lumped together in previous images.

The newest image released fromthe survey, of galaxy NGC 6822, reveals myriad stars that are young, hot andmassive, shown in blue.

Phil Massey, an astronomer at theLowell Observatory, said there are probably about twice as many massive starsin NGC 6822 than had been known before. He and his colleagues found an evengreater abundance of these stars, called Wolf-Rayet stars, in a galaxy calledIC 10.

Wolf-Rayet stars are typically muchmore massive than our Sun. They burn intensely, and they burn out about athousand times more quickly than Sun-like stars, losing much of their mass inthe process. But there is much about them that is not known. Massey's team isworking to count how many of these stars there are in the local galaxiescompared to longer-lived stars called red supergiants.

"A comparison of this ratiofrom galaxy to galaxy in our sample will provide us with some key tests ofstellar evolutionary theory concerning how massive stars evolve," Masseysaid.

The survey, called the LocalGroup Galaxies Survey, involves only nearby galaxies that are known to includesignificant new star formation. Other photographs in the past have providedmore detail of select regions of these galaxies, but the new survey isproviding more detailed and filtered information of entire galaxies.

Massey expects the survey's finalobservations will be made in September, filling out an image of the Andromedagalaxy. All data will then be made public, probably by January 2003. Finalresults and scientific papers will take another year to produce.

The National Optical AstronomyObservatory is conducting the survey using the National Science Foundation'sBlanco 4-meter telescope in Chile. Massey's colleagues on the survey are KnutOlsen, Chris Smith, Paul Hodge, Shay Holmes, George Jacoby, Nichole King andAbi Saha.

Travis Rector of the NRAO put theimage of NGC 6822 together. The colors were generated in part to make thegalaxy look like what your eye would see if you could see color at very faintlight levels, Massey said.

In the image, red stars withinthe body of the galaxy are red supergiants, while bright red stars outside thegalaxy are foreground stars in our Milky Way Galaxy.

NGC 6822 is located about 1.6million light-years from Earth, in the constellation Sagittarius. A member ofthe Milky Way galaxy's Local Group, it was discovered by E.E. Barnard in theearly 1880s.

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