Our massive star
Anna McLeod’s discovery provides clue on one of biggest questions in astronomy
ANew Zealand scientist has discovered a young, massive star in a neighbouring galaxy that appears to be 12 times bigger than the sun. Marsden Fellow Anna McLeod, of University of Canterbury’s School of Physical and Chemical Sciences, says the major astronomical discovery will drive significant advancement in the field of star formation.
“It also gives a further clue on one of the biggest questions in modern astronomy: how do massive stars form?” Dr McLeod said.
“Massive stars [. . .] regulate the formation of new generations of stars as well as the evolution of entire galaxies. Our discovery captures a massive star as it is forming, and it sheds light on to the formation mechanism.”
Dr McLeod is the lead author of the new article about the discovery, “A parsec-scale optical jet from a massive young star in the Large Magellanic Cloud”, co-authored with researchers in Germany, the UK and the US, published today in top scientific journal Nature.
The researchers say the star’s jet spans about 36 light years, making it among the largest jets of its kind to be found. The star powering the jet also appears to be about 12 times more massive than our sun.
The data came from the Very Large Telescope (VLT) in Chile, one of the largest optical telescopes. It is one of the most competitive telescopes on which to obtain precious observing time.
“The discovery . . . opens new doors in the field. As an added bonus, it also comes with a very rich data set and stunning images of a starforming region in our neighbour galaxy, the Large Magellanic Cloud,” Dr McLeod said.
While we understood how stars similar to our sun formed, that was not the case for stars with masses eight times that of our sun and above, “that are so important in regulating star formation in entire galaxies”.
In the paper, Dr McLeod presents evidence that high-mass stars form in a similar way to sun-like stars.
“We have detected a very young and still-forming massive star — a socalled young stellar object — which is launching a bipolar jet. The jet is direct evidence for what we call an accretion disk — a disk around the equator of the star through which the star is gathering matter and thus growing, which is what we see in lowmass stars.”