Betelgeuse (alpha Orionis) is one of the most well known stars. It is the second brightest star in Orion and distinguished by it’s red color. Betelgeuse is approximately 1,000 times larger than the Sun and emits more light than 100,000 Suns combined. Scientists believe Betelgeuse will become a supernova within a relatively short time – maybe within 10,000 years.
Recently the ESO (European Organization for Astronomical Research in the Southern Hemisphere) released some images showing the sharpest views ever of Betelgeuse. One of the ESO images is included to the right. This image shows a large plume of gas extending from the surface of the star into space. This plume of gas extends for a distance equal to the distance from the Sun to Neptune. Interestingly, the gas is not being ejected from the star evenly in all directions.
Why is this happening? Astronomers weren’t sure at first. They had two theories. The first theory proposed the gas was being ejected from the poles of Betelgeuse possibly because of the stars rotation. The other theory was that convection was creating the gas motions in the star. (Convection is the process you see when water boils. Hot water – which is less dense – moves from the bottom of the pan upwards and cooler water – which is more dense – moves downward.)
Additional investigation showed that gas bubbles (as large as Betelgeuse itself) are moving up and down in the star’s atmosphere. The movement of these gas bubbles is believed to be responsible for the ejection of the large plume of gas from the star’s surface.
You can read more about this research and the use of the Very Large Telescope at this link to the ESO Press Release.