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Central star is no dim bulb

Runner-up in the brilliance competition

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5:24pm, July 15, 2008
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And the silver medal goes to … the Peony nebula star. Observing the dusty center of the Milky Way, astronomers have found a hidden treasure: the second-brightest star known in the galaxy. Researchers had already known of the star’s existence, named for the flowery shape of its surrounding cloud of gas and dust. But the blanket of dust at the galaxy’s center had obscured the star’s true brilliance.

Examining infrared radiation from the star, which penetrates the blanket of dust, Lidia Oskinova of the University of Potsdam in Germany and her colleagues found that the star blazes with the light of 3.2 million suns. The team describes the findings, which rely on observations from NASA’s infrared Spitzer Space Telescope and the European Southern Observatory’s New Technology Telescope in Chile, in an upcoming Astronomy & Astrophysics.

The Peony nebula star began its life as a heavyweight, with an initial mass of about 150 to 200 times that of the sun. It’s evolved into a type of giant blue star called a Wolf-Rayet, known for its fierce winds of up to 1.6 million kilometers per hour. The star is also huge, with a radius roughly equal to the distance between Mercury and the sun. The star will eventually blow up in a supernova explosion, as will the brightest known star in the galaxy — another heavyweight called Eta Carina, which has an estimated luminosity equivalent to 4.7 million suns.

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