The famous Betelgeuse is a star in serious trouble. Not only is it rapidly approaching the end of its life, it’s also speeding toward a honking huge interstellar wall! Fortunately, this wall is made of dust, so it probably rates quite low on the red supergiant’s list of concerns.
This spectacular observation was captured by the European space telescope Herschel, which is sensitive to infrared light. Betelgeuse was the target, but as can be seen to the left of the image, an apparently vertical glowing structure can be seen (a high-resolution image can be downloaded here). Astronomers have calculated that the star’s bow shock will “impact” the wall in about 5,000 years time — the star itself will hit around 12,500 years later.
It was originally believed that the structure may be material that was flung from the dying star earlier, but analysis has shown that it is in fact stationary and did not originate from Betelgeuse. The structure may therefore be dust trapped in the interstellar magnetic field of our galaxy or the outer edge of a nearby stellar cloud illuminated by Betelgeuse’s light.
In addition to the glowing dusty wall is the incredible bow shock generated by Betelgeuse’s stellar winds, buffeting against the interstellar medium as the star powers through space at 30 km/s (19 miles per second). Our sun also has a bow shock that curves around the sun in its direction of travel, but Betelgeuse’s bow shock is inevitably more dramatic as its stellar winds are ferocious.
Betelgeuse is a massive star — around 1,000 times bigger and 100,000 times brighter than the sun — and is therefore predicted to end its life as a supernova. The red supergiant phase is violent; strong winds strip the outermost layers of the star, blasting them into space. Observations have even shown that the star’s shape is irregular, a sure sign that Betelgeuse is, quite literally, falling apart.
This observation was a part of research published in Astronomy & Astrophysics in December 2012.
Image credit: ESA/NASA