Betelgeuse, the red supergiant familiar from Orion's shoulder, keeps surprising us. After the mysterious Great Dimming of 2019–2020, when the star suddenly dimmed, it didn't just recover; it changed its ways. New radio observations at seven frequencies (from 22 to 485 GHz, corresponding to wavelengths from 1.36 cm to 0.62 mm) using the VLA and ALMA telescopes in 2021–2026 have let us peer into its bloated atmosphere.

It turns out that at 22 and 44 GHz, the brightness temperature (a measure of emission) has increased compared to historical minima before the dimming. But the most intriguing part: the temperature peaks not at the star's surface but at a distance of about 2.7 times its radius. That's farther out than previously thought, hinting at how the atmospheric density changes with height. Meanwhile, from the outer layers inward, the temperature drops from 3500 K to 2220 K — confirming the existence of a cool layer between the photosphere (visible surface) and the chromosphere (outer shell).

But the real surprise is the link to a possible companion. Recently, Betelgeuse was suspected of having a close companion on an orbit with a radius of about 2.3 times the star's radius. And now the radio data show that the ellipticity (elongation) of Betelgeuse's atmosphere changes in step with the orbital phase of this companion. It's as if an invisible dance partner periodically tugs at the gas envelope, distorting its shape. This isn't just coincidence — the correlation points to real gravitational or tidal influence.

So old Betelgeuse might be sharing its system with a dark neighbor that conducts its pulsations. This discovery not only explains the oddities in the star's shape but also gives us a new way to hunt for hidden objects around other supergiants.