Betelgeuse set to impact unknown barrier
New measurements from the joint ESA-NASA Herschel mission has revealed that Betelgeuse is set to impact a mysterious barrier of material in around 17,500 years time.
Betelgeuse is a red supergiant in everyone’s (or at least my) favourite constellation Orion, a star definitely past its mid life crisis and looking up its options in terms of which retirement home to go into. It is a thoroughly massive star at about 30 times the mass of our own Sun and has a diameter equivalent roughly to the outer diameter of our asteroid belt.
Astrophysicists are eagerly awaiting Betelgeuse to collapse on itself in a stunning supernova soon in astronomical terms, although this might in reality be anything in the next million years or so.
As part of this headlong dive towards its hari-kari supernova death, Betelgeuse has formed itself as a red supergiant, expanding from its previous size and sloughing off the outer layers of its photosphere as it changes from fusing Hydrogen atoms to Helium.
In this far infrared image from the Herschel observatory we can see Betelgeuse itself (right) and a couple of concentric rings on the left before a linear barrier on the extreme left. Now, I know what you’re thinking. Those rings are the blown off part of the photosphere.
Betelgeuse actually moves with such speed (around 30km/s) that it generates a phenomenon known as “bow shock” as the particles it produces (its own solar winds) crashes against the static particles of the interstellar medium as it passes through, producing the concentric rings that we see.
The mysterious barrier on the left (which the bow shock rings will impact in about 5000 years, with Betelgeuse itself impacting the barrier about 12.5 thousand years after that) is something of a mystery. Astronomers dont know what causes the barrier, but current theory is that it is either the outer edge of a faint dust cloud illuminated by Betelgeuse or a filament of dust lying along a galactic magnetic field line.
Image Credit: ESA/Herschel/PACS/L. Decin et al