The star Betelgeuse, the gleaming right shoulder of the constellation Orion, is nearing its end. One of the sky's brightest lights, Betelgeuse is losing its shine. Scientists have explained that the star is dimming due to the star pulsating. This phenomenon is quite common in red supergiants, and Betelguese has been known for decades into the group.
Betelgeuse is a “variable” star, known for wild fluctuations in its brightness. The star's brightness is observed dipping in the last hundred years, but scientists have never recorded it changing quite so fast. Such a strange behavior of the star has kept scientists pondering: Is this a sign that Betelgeuse might go supernova?
The star will likely meet its demise within the next 100 million years, which is practically a couple days in cosmic time. When the Betelgeuse goes supernova, it would explode into a bright, dazzling light that could be visible even during the daylight.
Betelgeuse is over 10 times more massive than the Sun and wide enough that, if we moved it to our solar system, it would extend past the orbit of Jupiter. “Supergiants” like this tend to live fast and die young, and Betelgeuse’s red colour indicates that it has already moved to one of the last stages of a star’s life: fusing helium atoms into ever-heavier elements.
The star loses the outward pressure that kept it from collapsing under its immense weight when a star runs out of material to fuse in its centre. The resultant core-collapse happens in half a second, far faster than it takes the star's surface.
Eventually, all the material in the core will become iron — an element too heavy for further fusion. These combine to form neutrons, and in the process release, high-energy particles called neutrinos. The star will succumb to the intense inward crush of its gravity. Betelgeuse will go supernova.
Supernova is among the most powerful phenomena in the universe. Even though only a tiny fraction collides with the stellar material; its numbers and energies produced are more than enough to launch a shockwave capable of exploding the star.
Physics graduate student Jared Goldberg along with other researchers has published a study on how a star's pulsation will affect the ensuing explosion when it does reach the end. He said, "We wanted to know what it looks like if a pulsating star explodes at different phases of pulsation".
For the simple pulsation case, the team's model yielded similar results to the models that didn't account for pulsation. Goldberg explained, "It just looks like a supernova from a bigger star or a smaller star at different points in the pulsation."
The researchers have discovered that as light leaks out fro progressively deeper layers of the explosion, the emissions would appear as though they were the result of supernova from different sized stars.
Goldberg clarified, "Light from the part of the star that is compressed is fainter just as we would expect from a more compact, non-pulsating star."
(with inputs from agencies)
Image Credits: NASA