Protostar provides glimpse into stellar formation

Scientists from Cambridge University have discovered a young star which could help researchers understand how the largest stars in the Universe are formed.

The protostar is more than 30 times the mass of the Sun and is almost 11,000 light years away. The star is still gathering material from its parent molecular cloud — an interstellar cloud where molecules form. Scientists believe this young star could increase in size.

Dr John Ilee, lead author from the Cambridge Institute of Astronomy, said: “An average star like our Sun is formed over a few million years, whereas massive stars are formed orders of magnitude faster — around 100,000 years. These massive stars also burn through their fuel much more quickly, so they have shorter overall lifespans, making them harder to catch when they are infants."

The young star is located in an infrared dark cloud, which means conventional telescopes are unable to observe the region. Scientists had to use the Submillimeter Array in Hawaii and the Very Large Array in Mexico which use long wavelengths of light to see through the cloud and observe the star.

The scientists calculated the amount of radiation emitted by cold dust near the star and identified the molecular footprint of different products in the gas. From their measurements, they were able to identify a Kleperian disc — one which rotates more quickly at its centre instead of its edge. This disk is between two and three times the mass of the Sun.

Ilee said: “This type of rotation is also seen in the Solar System - the inner planets rotate around the Sun more quickly than the outer planets. It's exciting to find such a disc around a massive young star, because it suggests massive stars form in a similar way to lower mass stars, like our Sun."

The researchers will now observe the same region with the Atacama Large Millimetre Array in Chile to find out more information about the protostar. The study was published in Monthly Notices of the Royal Astronomical Society.