Irish astronomers snap most detailed image ever of another star

26 Jun 2017

The ALMA telescope used to capture the image of Betelgeuse. Image: ESO/B. Tafreshi (

A team of Irish astronomers have managed to capture an image of unprecedented detail of another star – that isn’t the sun – called Betelgeuse.

NASA recently announced a new mission to launch the Parker Solar Probe to ‘touch the sun’ in order to better understand its complex and peculiar outer atmosphere, but when it comes to other stars in the universe it gets a lot trickier.

However, a team of Irish astronomers from the Dublin Institute of Advanced Studies (DIAS) led by Eamon O’Gorman has now given us our best glimpse yet of a stellar body outside of our own solar system.

Using the world’s largest radio telescope – the Atacama Large Millimetre/submillimetre Array (ALMA) in Chile – the DIAS team has managed to make the most detailed image of the surface of the red supergiant, Betelgeuse.

Located in the constellation of Orion approximately 650 light years away, Betelgeuse is absolutely enormous, being about 1,400 times larger than the sun and more than 1bn times larger in terms of volume.

Typically, stars of a similar size to Betelgeuse tend to expel an enormous amount of energy back into the interstellar medium via stellar winds that can help seed the next generation of stars and planets.


The image captured by ALMA of Betelgeuse. Image: ESO/ALMA/P Kervella

According to O’Gorman, the new image of Betelgeuse reveals a star that is tumultuous and unpredictable in nature.

“We have known for decades that the visible surface of Betelgeuse is not uniform, but ALMA has now shown in beautiful detail that the temperature in its inner atmosphere is also not uniform,” he said.

“It looks like these temperature fluctuations could be caused by magnetic fields, similar to what we see on the sun, our nearest star.”

Consisting of 66 gigantic 12-metre and seven-metre antennas, ALMA’s new found star photography means that it can now provide astronomers with the capabilities to image surface features on nearby stars while also directly measuring the temperature of these features.

The team’s research has now been published in the journal Astronomy & Astrophysics.

Betelgeuse size comparison

A size comparison of Betelgeuse with other bodies in our solar system. Image: Clem & Adri Bacri-Normier (

Colm Gorey was a senior journalist with Silicon Republic