Astronomers have discovered a fast aging, huge star which has been never seen before in the Milky Way galaxy. The star was discovered through the Hubble Space Telescope. Astronomers have named it Nasty 1, which is a play on its catalog name of NaSt 1.
Astronomers assume that the strange star may be representation of a brief transitory stage in the evolution of extremely massive stars.
Identified as Wolf Rayet star in the past, it got discovered decades ago and was conisdered as a rapidly evolving which is larger than the sun. The star loses its layers of hydrogen quickly and exposing its super hot and bright helium burning core.
But Nasty 1 doesn’t look like a typical Wolf Rayet star.
Jon Mauerhan of the University of California, Berkeley, and study leader said, “We were excited to see this disk-like structure because it may be evidence for a Wolf-Rayet star forming from a binary interaction, there are very few examples in the galaxy of this process in action because this phase is short-lived, perhaps lasting only a hundred thousand years, while the timescale over which a resulting disk is visible could be only ten thousand years or less.”
The star evolves rapidly but loses hydrogen in the process and starts swelling. According to researchers, this can take place much faster compared to the life of other stars and Nasty 1 is believed to be only few thousand years.
Nathan Smith of the University of Arizona in Tucson, and co-author of the study said, “We’re finding that it is hard to form all the Wolf-Rayet stars we observe by the traditional wind mechanism, because mass loss isn’t as strong as we used to think, 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.”
Observing Nasty 1 was no piece of cake, though. The star is covered heavily by gas dust, thus blocking the view of even an advanced telescope such as Hubble.
Mauerhan said, “What evolutionary path the star will take is uncertain, but it will definitely not be boring, Nasty 1 could evolve into another Eta Carinae-type system. To make that transformation, the mass-gaining companion star could experience a giant eruption because of some instability related to the acquiring of matter from the newly formed Wolf-Rayet. Or, the Wolf-Rayet could explode as a supernova. A stellar merger is another potential outcome, depending on the orbital evolution of the system. The future could be full of all kinds of exotic possibilities depending on whether it blows up or how long the mass transfer occurs, and how long it lives after the mass transfer ceases.”