When Will Betelgeuse Explode?

There are stars in our sky that we recognize on sight either because they are the brightest or because they are part of a constellation. One such star is known as Betelgeuse and there is one big question often asked about this star. The big question is “When will Betelgeuse explode?”

In this article we are going to learn more about this star which we can all see in the clear night sky but which most of us do not know that much about. We will learn about what type of star this is, where it can be seen and of course the mystery of when it may be due to explode.

What Is Betelgeuse?

The star dubbed Betelgeuse (or Alpha Orionis) is what is referred to as a red supergiant star or spectral type M1-2. It is one of the largest and the 10th brightest star in the night sky. Obviously to the naked eye measuring a star’s brightness compared to the millions of others we can see is not really possible. However Betelgeuse is also further distinct.

Betelgeuse is the second brightest star after Rigel found in the constellation known as Orion. Upon inspection you might spot it as the star of the constellation that has a distinct reddish hue in comparison to the others in Orion.

What if Betelgeuse Was Our Sun?

Our own sun is also a star but it is classified as a yellow dwarf star. If our solar system had Betelgeuse at its center in place of the sun it would be a very different system. Being much larger than our own sun, Betelgeuse’s surface would extend beyond the orbits of Mercury, Venus, Earth, Mars and Jupiter. This essentially means our planet would not exist.

Calculations suggest that Betelgeuse is between 10 – 20 times the size of our own sun although this has been hard to confirm for various reasons.

Where Is Betelgeuse in the Night Sky?

As mentioned, Betelgeuse is one of the stars in the constellation Orion. It is on the right shoulder of the constellation although when viewed from earth it appears to be on the left. It sits above the three stars that make up Orion’s Belt.

How Old Is Betelgeuse?

Our own sun is almost 5 billion years old but Betelgeuse is a relative baby star at around 10 million years. Its sheer size means that it burns harder and faster than our sun. It also means that Betelgeuse is reaching the end of its life as a star at a rapid pace. Our own sun will likely last another 10 billion years but Betelgeuse is living fast and will ultimately die young.

Observational History

Clearly visible from earth the existence of Betelgeuse has been no secret from humans since they first developed on this planet. It was however astronomer Ptolemy who first described the color of Betelgeuse as red. Three centuries earlier Chinese astronomers described it as yellow which may indicate a shift from yellow supergiant to red supergiant during that time.

Prior to our modern day systems of stellar classification in the 19th century Angelo Secchi included Betelgeuse as one of the prototypes for his Class III stars. Around 1836 Sir John Hershel began to note variations in the brightness of Betelgeuse.

It would at times outshine fellow Orion star Rigel but at other times appear less bright. There were significant and clear changes in the brightness of the star which were recorded periodically. This variation caused some astronomers over the years to deem it the alpha star over Rigel.

How Far Away Is Betelgeuse?

As with all stars in our night sky the light we are seeing has traveled vast distances and due to the speed of light we are actually seeing light that was emitted in the past. The further a star is from us the longer the light takes to reach us. This is measured in light-years which indicates a distance that light will travel in one year.

The light we see from Betelgeuse has traveled around 700 light-years to get to us which essentially means the star as we see it today is as it appeared 700 years ago. So we see Betelgeuse as it was when Robert the Bruce was King of Scotland and Edward II was on the English throne. We will not see the star as it is today for seven centuries.

The Great Dimming

There is a reason why many are questioning when Betelgeuse may explode and this comes from events in the fall of 2019. An event dubbed as “The Great Dimming” saw a drastic dip in the star’s emitted light which within a couple of months saw a 60% decrease in the star’s brightness.

This led many experts to wonder if this was a sign that Betelgeuse was entering a pre-supernova phase which usually precedes a massive star’s explosion. If this were the case it would be the closest supernova event to earth and could potentially be observed and recorded.

The star however returned to its former glowing glory by April of 2020 leaving a lingering mystery which would not be resolved until 2021. Data collected from NASA’s Hubble telescope revealed that the star spewed a giant piece of its surface material out into space. This material cooled into a dust cloud which essentially obscured some of the star’s light.

This is not uncommon for surface material to be ejected but the magnitude of this event created a cloud of dust that would for a short period make the star appear more dim. It is estimated the eruption was 400 billion times larger than a normal ejection from the star.

When Will Betelgeuse Explode?

The Great Dimming was not the foreboding sign of Betelgeuse exploding but one thing is sure. Like all stars one day it will supernova and become either a neutron star or a black hole. Scientists are torn on exactly when this will happen however with estimates ranging from 10,000 – 100,000 years from now.

Our fascination with this bright, giant and relatively close star will mean we will take note of all the signs that may appear. It is however unlikely that we will see the death of this star ourselves so for now even though we are seven centuries behind on what is happening to the star we can be confident it is still burning in the depths of space.

Final Thoughts

Despite excitement in 2019 that Betelgeuse may be entering its final phases of life the reality was more mundane. Betelgeuse will one day explode and become something we can no longer see in our night sky but this is unlikely to happen in our lifetime or for that matter the lives of generations of our descendants. This star likely has at least 10,000 years left, maybe even 100,00.