Is Betelgeuse, the red supergiant star, about to go supernova? | Explained

Is this the final countdown?

The universe never ceases to amaze us with its wonders, and one of the most intriguing celestial objects captivating our attention is Betelgeuse, a red supergiant star located in the Orion constellation. Recently, scientists have been buzzing with excitement about its impending fate. Will Betelgeuse, the red giant star, blow up in our lifetime? Let’s explore the thrilling possibilities surrounding this stellar phenomenon.

The Life Cycle of a Red Giant

How the star dies depends on what type of star it is. Massive stars transform into supernovae, neutron stars, and black holes, while average stars like the Sun end their lives as a white dwarf surrounded by a disappearing planetary nebula. 

To understand the current state of Betelgeuse, let’s delve into the life cycle of a red giant star. These massive, aging stars have exhausted their hydrogen fuel and expanded, causing them to appear red in color. As they continue burning heavier elements like helium, they undergo various stages, gradually consuming the elements of the periodic table. 

Betelgeuse, the famous red giant star, has behaved oddly in recent years, and astronomers now believe the end is close. In late 2019, Betelgeuse caught the attention of astronomers worldwide when it experienced a phenomenon dubbed the “Great Dimming.” This event sparked speculation about the star’s imminent explosion. However, scientists concluded that the dimming was likely caused by a dust cloud, suggesting that Betelgeuse’s supernova was still tens or hundreds of thousands of years away.

But recent research on the massive red giant star Betelgeuse suggests that it is in its late carbon-burning stage (near the end of its life) and may explode as a supernova within a few decades.

How have astronomers found the stage of Betelgeuse?

Astronomers have suggested the stage of the red giant star by studying its pulsations. Betelgeuse undergoes periodic expansion and contraction (similar to a boiling pot releasing steam), causing variations in its brightness. By analyzing these pulsations, researchers can infer their current state.

The Predicted End: The Unveiling of a Star’s Fate

Like our sun, most stars combine hydrogen to make helium and some energy. The outer push of this energy balances the pull of gravity and keeps the star from collapsing.

Massive stars like Betelgeuse run out of hydrogen fuel in only a few crore years, at which point they switch to using helium to make carbon. Helium fusion gives off less energy than hydrogen fusion, so the star needs to burn more helium to stay solid and not fall apart. The helium runs out in about ten lakh years.

At this time, red giants like Betelgeuse burn carbon, then silicon, and quickly eat one by one of the elements on the periodic table until their cores are full of iron, whose fusion takes more energy than it gives off.

Each step is shorter than the one that came before it. Once the core has a lot of iron, the star’s temperature and pressure go down. If nothing stops it, gravity will squeeze the centre until it becomes a neutron star or a black hole. 

The Final Countdown

The exact timing of Betelgeuse’s supernova remains uncertain. Some experts believe it could happen sooner than previously thought, possibly within our lifetime, while others maintain that it might take several thousand years. Regardless, one thing is clear: Betelgeuse is destined to explode eventually, illuminating the night sky with an awe-inspiring celestial firework display.

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