The Great Betelgeuse dimming event in high resolution


ESO/J. Drevon et al.

it happened. Some people believe that a star nearing the end of its life will explode and become a supernova. In this week’s vivid photo, astronomers shed light on how Betelgeuse became fainter, confirming that GDE is not the precursor to a spectacular supernova after all – sorry ! Here we see what Betelgeuse looked like in December 2018, February 2020 and December 2020, attracting famous stars before, during and after GDE. A team led by Julien Drevon, Florentin Millour and Pierre Cruzalèbes from the University of the Côte d’Azur (France) used the MATISSE infrared instrument on ESO’s Very Large Telescope Interferometer (VLTI) to obtain the images Has high resolution of stars. The top images here show its “surface” or photosphere, while the bottom images show silicon monoxide, a molecule that can act as a seed to form dust particles.

A keen eye can see that Betelgeuse’s photosphere became brighter during what is known as a dimming event. We now know that dust is created in GDE, causing the star to appear dimmer to us in visible light, but brighter to MATISSE when the dust glows in infrared light. Additionally, changes in the structure of the photosphere and silicon monoxide are consistent with both cold spot formation on the star’s surface and dust cloud ejection. The size of Betelgeuse in the sky is equivalent to a 1 euro coin seen from a distance of 100 km. VLTI combines light from multiple telescopes to create a much larger “virtual” telescope, capable of observing small structures on Betelgeuse. Thanks to that, we can observe in detail how this giant star ages and develops.