An Irish PhD student has been reflecting on the "incredible" experience of helping to solve the mystery of the dimming Betelgeuse star.

The red supergiant in the constellation of Orion became visibly darker in late 2019 and early 2020, puzzling the astronomy community.

Some speculated that it might be about to die in a supernova explosion.

Wide-field view of the constellation of Orion where Betelgeuse is located. (Credit: ESO/N. Risinger)

Betelgeuse's dip in brightness - a change noticeable even to the naked eye - led a team of astronomers to point the European Southern Observatory’s Very Large Telescope (ESO’s VLT) towards it in late 2019.

Dubliner Emily Cannon, an Astrophysics PhD student at KU Leuven in Belgium, is a member of that team.

Ms Cannon said: "Betelgeuse regularly changes in brightness, every 400 days. But over this period, it was dipping in brightness a lot more than usual.

"So, we wanted to investigate what could be causing this dimming of the star. Using the VLT in Chile’s Atacama Desert, we were able to image the actual surface of the star, so we could see exactly what was happening."

Never-before-seen images released by the research team earlier this week clearly show how the star's brightness changed.

Images, taken with the ESO's Very Large Telescope, show the surface of Betelgeuse during its unprecedented dimming, which happened in late 2019 and early 2020. (Credit: ESO/M. Montargès et al.)

In a study, published in Nature, the astronomers revealed that the changes were caused by a giant dust cloud shading the star, which in turn was the result of a drop in temperature on Betelgeuse’s stellar surface.

Ms Cannon said: "People have monitored Betelgeuse for 150 years and this has never happened before. We have never witnessed an event like it. So, for this to occur at the time when I'm studying red supergiants for my PhD was pretty incredible!"

The new research also confirmed that Betelgeuse's 'Great Dimming' was not an early sign that the star was heading towards its imminent death in a spectacular supernova explosion.

A supernova has not been observed in our galaxy since the 17th century.

Ms Cannon said: "As much as I would have liked to have witnessed a supernova, it is nice that Betelgeuse is still there, and we can continue to study it.

"It's been amazing to see just how interested people are in what's happening - professional and amateur astronomers alike. The story has made headlines around the world. If you look on Twitter, people have been sharing it ever since the research came out.

"Looking up at the stars at night, these tiny, twinkling dots of light seem perpetual. The dimming of Betelgeuse breaks this illusion."