Space Telescope Science
Astronomers have spent decades trying to determine the oddball behavior of an aging star nicknamed "Nasty 1" residing in our Milky Way galaxy. Nasty 1 was identified as a Wolf-Rayet star, a rapidly evolving star that is much more massive than our sun. The star loses its hydrogen-filled outer layers quickly, exposing its super-hot and extremely bright helium-burning core.
But Nasty 1 doesn't look like a typical Wolf-Rayet star. Astronomers using NASA's Hubble Space Telescope had expected to see a bipolar outflow of twin lobes of gas from the star, perhaps similar to those emanating from the massive star Eta Carinae. The astronomers were surprised, however, to find a pancake-shaped disk of gas encircling the star. The vast disk is nearly 1,000 times the diameter of our solar system. It may have formed from the interaction between Nasty 1 and an unseen companion star. The star may represent a brief transitory stage in the evolution of extremely massive stars. Nasty 1's nickname was derived from its catalog name of NaSt1.