Betelgeuse’s enigmatic environment

Composite colour image of the Herschel PACS 70, 100, 160 micron-wavelength images of Betelgeuse. North is to the top left, east is to the bottom left, and the image is about 25 arcminutes across.

The star (centre) is surrounded by a clumpy envelope of material in its immediate vicinity. A series of arcs 6–7 arcminutes to the left of the star is material ejected from Betelgeuse as it evolved into a red supergiant star, shaped by its bow shock interaction with the interstellar medium. A faint linear bar of dust is illuminated at a distance of 9 arcminutes and may represent a dusty filament connected to the local Galactic magnetic field or the edge of an interstellar cloud. If so, then Betelgeuse’s motion across the sky implies that the arcs will hit the wall in 5000 years time, with the star colliding with the wall 12 500 years later.