Surprising Cocoons Found Enveloping Giant Stars

From Space.com:

Scientists looking at three rare and radiant pulsating stars have found they each are surrounded by a fairly bright layer of matter, a “cocoon,” that has never before been detected around stars of this kind.

The astronomers think the cocoons form as the stars shed huge amounts of mass at a tremendously faster rate than normal stars like the Sun.

The cocoons are about two to three times larger than the stars and about 4 percent as bright, very bright considering that these pulsating stars themselves are incredibly radiant. One of the enveloped stars is 400 times brighter than the Sun.