So Betelgeuse is Back to Normal?

A few months ago, well actually almost a year ago, astronomers studying Betelgeuse noticed some major dimming in the star, and the news spread like wildfire!

The issue arised when in 2019 astronomers observed dramatic dimming in the Southern part of the star, making it about 3 x fainter! With Betelgeuse being an enormous red supergiant we know its days left are few, so many thought extreme dimming meant the star is about to go supernova!

This comparison image shows the star Betelgeuse before and after its unprecedented dimming. The observations, taken with the SPHERE instrument on ESO’s Very Large Telescope in January and December 2019, show how much the star has faded and how its apparent shape has changed. Credit: ESO/Montargès et al.

So what caused the dimming?

A large group of astronomers lead by Andrea Dupree from multiple observatories have gathered evidence to suggest that the reason behind the dimming is an ejection of material from the star itself!

Just before the dimming, the team observed a large pulse of plasma propagating outwards in the Southern part of Betelgeuse. This super hot plasma created a great increase in UV ray emission from Betelgeuse, and would naturally lead to material being ejected from the star once the pulse reached the surface.

A Coronal Mass Ejection from our Sun!

This creates a mass ejection event, similar to ones we see on our Sun…just much much larger!

As the ejected material moves through space, it cools and becomes a dust cloud surrounding Betelgeuse. Dust (being dust) blocked the light emitted from the star and caused the dimming.

We’re not sure why there was a pulse of material in the first place, but the top idea suggests a mix of the material getting a boost from convection cells in the photosphere, PLUS the movement of material being in phase with Betelgeuse’s natural pulsation period.

As of today, Betelgeuse is back to normal and its brightness has also returned to what it was before!

Featured Image: Rogelio Bernal Andreo


    • A supernova would be fantastic, but it still could happen soon! I’m quite interested to hear more about the event; the data might help teach us about the core of stars, something which we don’t know a lot about!

      Liked by 1 person

    • I know! Amazingly enough, our ancestors actually witnessed the Crab Nebula’s birth just under 1’000 years ago! It might be a stretch, but there is a chance we could see some kind of explosion within our lifetime.

      Liked by 1 person

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