Astronomers said ‘Betelgeuse Betelgeuse Betelgeuse’ and a new star appeared!

We each cognize astir Betelgeuse, nan reddish supergiant prima successful nan constellation of Orion.  

At astir 11 cardinal years aged and 16 times heavier than nan Sun, Betelgeuse is nan closest red supergiant prima to us, a staggering 700 times larger than nan Sun. 

Put different way, if you replaced nan Sun pinch Betelgeuse, nan outer edges of nan prima would scope each nan measurement past Jupiter. 

Caption: The Solar System pinch nan Sun replaced by Betelgeuse.
Credit: ALMA (ESO/NAOJ/NRAO)/E. O’Gorman/P. Kervella

VARIOUS VARIABLES

Betelgeuse is simply a variable star, which is to opportunity its brightness changes complete time. The prima gets brighter and darker each 400 days aliases truthful arsenic nan prima grows and shrinks – deliberation of it a spot for illustration breathing. 

Variable stars are rather common, pinch various beingness mechanisms explaining their changing brightness. 

Caption: The adaptable brightness of Betelgeuse including the ‘Great Dimming‘ of 2019/20.
Credit: Pilate et. al 2024, CC BY 4.0

But location seems to beryllium different much subtle alteration successful brightness of Betelgeuse each 6 years, and astronomers conscionable couldn’t find an mentation that decently described it.

Some scientists speculated this was caused by a companion star connected a six-year agelong orbit stirring up Betelgeuse’s outer atmosphere. This would lucifer nan data, and it’s a bully idea, but a bully presumption has to clasp up to observational fact. 

THEY CAME, THEY SAW, THEY PREDICTED

Because Betelgeuse has specified a agelong and elaborate observational history, astronomers were capable to make highly meticulous predictions astir nan orbit of this hypothetical companion star. 

They predicted that if this prima existed, it would beryllium furthest from Betelgeuse (and frankincense nan easiest to see) connected 18 December 2024. So, precocious past year, scientists utilized nan ‘Alopeke instrumentality connected nan Gemini North scope successful Hawaii to look for it.  

Caption: The Gemini North observatory houses nan ‘Alopeke instrument.
Credit: Noirlab

Atmospheric turbulence is nan bane of each ground-based astronomy, causing stars to ‘twinkle’. 

While somewhat pleasant for backyard stargazing, for master astronomers this intends that pictures of distant objects thin to ‘smear out’, making it very difficult to attraction connected mini targets for illustration stars successful awesome detail.  

EXPOSING ITSELF

The ‘Alopeke instrumentality takes a caller attack to this problem. Instead of taking agelong vulnerability pictures – during which clip nan turbulence successful nan ambiance smears retired stars – it takes hundreds of pictures per second, each vulnerability only a fewer milliseconds long. 

This fundamentally ‘freezes out’ immoderate atmospheric distortion, which tin beryllium accounted for later, without smearing nan image of nan star. 

In nan end, nan astronomers took 6000 pictures of Betelgeuse successful this way. And what was nan result? 

Caption: Betelgeuse’s companion prima (blue, little left) and Betelgeuse (orange, centre).
Credit: Howell et. al 2025

This detection, if verified by early observations, is simply a stunning confirmation of nan predictive powerfulness of bully science. 

Analysing each nan information takes sizeable time, and by now nan prima is erstwhile again mislaid successful nan glare of Betelgeuse. According to orbit modelling, nan adjacent clip to spot nan prima astatine its top region from Betelgeuse will beryllium successful November 2027. 

There will beryllium nary shortage of astronomers fresh to effort and drawback a glimpse of it.