Stellar heavyweights may be born in similar manner as lightweights like our Sun

Washington, January 28 (ANI): Observations at the Gemini Observatory are providing convincing new evidence that the most massive stars may be born in much the same manner as lightweights like our Sun.

Ben Davies, of the University of Leeds (UK) and the Rochester Institute of Technology, led an international team of researchers who brought infrared sensitivity and the extreme resolution of adaptive optics to bear on the problem.

This allowed the team to penetrate the obscuring gas and dust clouds surrounding the massive proto-star W33A.

Davies' team calculated that the prenatal star is at least 10 times more massive than our Sun, and is still rapidly growing.

According to Davies, this is the first time they have been able to unravel the dynamics deep inside a heavyweight stellar nursery at this level of detail.

"We've caught a massive star in the act of formation, and found signatures of an accretion disk embedded within a torus of gas and dust. We also see material being blasted away from the poles at speeds of up to 300 kilometers per second," he said.

"These features are all common to the formation process found in much smaller stars," he added.

The massive star forming inside of W33A is completely obscured in optical light, but, according to Davies, "While the optical light is attenuated by about a factor of 10,000, much of the infrared light can pass through the intervening material. This affords us a glimpse of what is happening deep inside W33A's natal cloud."

Observations with adaptive optics and infrared spectroscopy are catching massive stars 'in the act' of forming.

Davies' team utilized the power of adaptive optics to remove atmospheric blurring and then dissected the light using the Near-Infrared Integral Field Spectrograph (NIFS) on the Frederick C. Gillett Gemini North telescope on Hawaii's Mauna Kea.

NIFS creates what is sometimes called a spectral image consisting of about 2,000 individual spectra in a square array that covered the heart of W33A.

These data are assembled into a "datacube" which allow the scientists to look at individual features of the spectra at each point and assemble a multi-dimensional image of the environment around the birthing star.

"We were not only able to resolve the inner nebula on small spatial scales, but also probe its dynamics by measuring the Doppler-shift of light from the glowing gas to determine its velocity and how it flows around the forming star," said Davies.

"This is an amazingly powerful tool for understanding the inner workings of how stars actually form," he added. (ANI)