Science

Astronomers nickname one-of-a-kind Wolf-Rayet star ‘Nasty 1’

The Hubble Space Telescope recently spotted a star never-before-seen in the Milky Way, or anywhere else in the entire universe. The massive star lies approximately 3,000 light-years from Earth and has been tentatively marked a Wolf-Rayet.

But while most Wolf-Rayet stars are noted by their twin polar lobes of burning gasoline, the star is surrounded by a heavy, flat disk of gas, measuring about 2 trillion miles wide. Scientists think they’re observing a Wolf-Rayet in a never-before-experienced (and likely short-lived) transition phase.

The star’s catalog name, NaSt1, is inspired from the two astronomers who discovered it in 1963, Jason Nassau and Charles Stephenson.

Wolf-Rayet stars are defined by their large size and exposed insides. They swell in size and their super-hot helium-burning cores are brought out, as these massive stars are stripped of their hydrogen-filled outer layers.

Lately, the main explanation for Wolf-Rayet hydrogen depletion was eroded. Scientists believe strong stellar winds from companion stars below the outer layers of gas away. However, Nasty 1 suggests theft is likely also involved. Astronomers dub the theft ‘mass-exchange.’

Nathan Smith, an astronomer at the University of Arizona in Tucson and co-author of a new paper on the star, expanded, “Mass exchange in binary systems seems to be vital to account for Wolf-Rayet stars and the supernovae they make, and catching binary stars in this short-lived phase will help us understand this process.”

Sometimes, gas is lost in the gravitational tug-of-war between the two stars, which may explain the giant gas disk surrounding Nasty 1.

“That’s what we think is happening in Nasty 1. We think there is a Wolf-Rayet star buried inside the nebula, and we think the nebula is being created by this mass-transfer process. So this type of sloppy stellar cannibalism actually makes Nasty 1 a rather fitting nickname,” said Jon Mauerhan, a researcher at the University of California, Berkeley.

When the Wolf-Rayet star runs out of material, this mass-transfer movement will end. Sooner, the gas in the disc will dissolve, providing a clear view of the binary system.

This is issued in the Monthly Notices of the Royal Astronomical Society.

Source: http://www.upi.com/Science_News/2015/05/22/Astronomers-nickname-one-of-a-kind-Wolf-Rayet-star-Nasty-1/2331432295554/