Dying Star Betelgeuse Spews Fiery Nebula
Betelgeuse, some 640 light-years from Earth in the constellation Orion, may look pretty healthy when you see it shining in the night sky it is one of the brightest stars out there but as this infrared image from the European Southern Observatory ESO shows, Betelgeuse is falling apart… literally.
It’s been known for some time that Betelgeuse is belching huge clouds of stellar plasma into space — this is a symptom of the star’s age and size. Betelgeuse is a red supergiant star a fraction of the age of our sun, but because it is so massive (18 times the mass of the sun) it lives fast and dies young.
The 10 million year-old star has run out of hydrogen in its core — and is now fusing helium into carbon and oxygen — causing Betelgeuse to “puff up” to gargantuan proportions. If Betelgeuse was our sun, it would fill the entire inner solar system with its surface reaching the orbit of Jupiter! Earth would be toast.
The interior of the star is a violent bubbling mess, with huge plumes of searing hot plasma warping the shape of the star. Observations have previously shown Betelgeuse to be “lumpy,” rather than a neat, spherical star. There are also some indications that the star is also shrinking, potentially revealing it is close (in cosmic timescales) to collapsing and exploding as a supernova — but never fear, Betelgeuse poses no threat to life on Earth.
In the final stages of a red supergiant star’s life, huge quantities of material are blown into space. As this ESO image shows, Betelgeuse is creating a vast, previously unseen, dusty cool nebula, extending 60 billion kilometers from its surface.
In the center of the image, the small red disk is Betelgeuse and the surrounding cloud (inside the black disk) is previous observations of plasma being belched into space. The colorful cloud surrounding the black disk comprises the new ESO observations taken by the ESO’s Very Large Array (VLA).
The extended nebula has never been spotted before as Betelgeuse is so bright it swamps any light emitted from the nebula. By using the VLA’s VISIR instrument to block out the light coming directly from Betelgeuse (using an occulter), the nebula — most likely composed of silica and alumina dust — glows in infrared wavelengths as it is heated by the star. It is worth noting that despite the extended nebula’s “fiery” appearance, it is actually composed of cool material — hence why it can only be detected in infrared wavelengths. Short infrared wavelengths are represented with a blue glow and longer infrared wavelengths are represented with a red glow.
This is a wonderfully intimate view of a massive star’s death, and with the help of the VLA, we have a ringside seat.
– by Ian O’Neill
Credit/source: ESO/P. Kervella