Artist’s impression of the disc surrounding the massive young star as it grows. Credit: A. Smith, Institute of Astronomy, Cambridge
Astronomers have discovered a young star about 30 times the mass of the Sun in our Galaxy, giving rare insight into how massive stars form.
The young star is about 11,000 lightyears away and is still gathering material from its surrounding molecular cloud, meaning it is still growing.
A team led by the University of Cambridge studied the star and found that it is growing from a rotating disc of gas and dust, just like the Sun.
Massive stars are those with a mass at least eight times greater than the Sun, and they do exist in the Milky Way.
However, they are difficult to study because they do not live very long.
They also form in the blink of an astronomical eye, meaning it is very unlikely to spot one still in the formation process.
“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,” says lead author Dr John Ilee from Cambridge’s Institute of Astronomy.
“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 team were able to use the Submillimeter Array in Hawaii and the Karl G Jansky Very Large Array in New Mexico to observe the star in long wavelengths and peer through the gas and dust surrounding it.
They were able to measure how much radiation was being emitted by cold dust near the star and analyse the molecules in the surrounding gas to discover a Keplerian disc.
This is a kind of accretion disc that from which young stars grow, but in a Keplerian disc, the centre is rotating more quickly than the outer section.
“This type of rotation is also seen in the Solar System - the inner planets rotate around the Sun more quickly than the outer planets,” says Ilee.
“It’s exciting to find such a disc around a massive young star, because it suggests that massive stars form in a similar way to lower mass stars, like our Sun.”