One of the sky’s brightest stars has been exhibiting some pretty unusual behavior.
Since October 2019, this massive red supergiant, named Betelgeuse, has been losing its sparkle
leading many scientists to wonder whether the star is headed toward its demise
by way of a supernova explosion.
And me to wonder if it will blow if we say its name three times.
Like the Tim Burton character, Betelgeuse—also pronounced Betelgeuse—
is known for its erratic behavior,
shrinking then expanding and dimming then flaring on a semi regular basis.
This ruddy colored star is located at the top left of Orion’s belt, the most visible part of the constellation.
And it’s huge, with a mass that’s over 10 times the size of our Sun,
and a diameter that’s roughly 1,000 times larger.
This 8-9 million year old star is also super bright,
frequently ranking among the top 10 brightest stars in our night sky.
At least, it did.
According to recent reports, Betelgeuse has cooled by roughly 100 Kelvin since September 2019
and is now hovering around 1.6 apparent magnitude,
a significant drop from its average range of 0.4 to 1.2 magnitudes of brightness.
This supergiant has now been demoted to about the 21st brightest star in the galaxy,
which is the faintest it’s been in at least a century.
So what gives?
Well, one might be inclined to attribute the star’s fluctuating brightness to its regular "cycles,"
which occur in both short, several month-long periods and longer ones lasting about 6 years,
which affects how dim or bright Betelgeuse appears.
Could it just be that these cycles are overlapping, or maybe that clouds of debris are blocking the star’s light?
Well, maybe—but other strange things are also happening to the star.
For one, it’s shedding quite a lot of mass,
but instead of generating lots of heat like scientists would assume, it’s staying cool.
Betelgeuse is also defying expectations with its super-speed rotation,
which has been observed to be spinning around 150 times faster than would be expected for a star this big.
And nothing we’ve observed so far can really account for this.
Although there is a theory that Betelgeuse captured a star 100,000 years or so ago,
in turn inheriting its angular momentum and a faster rotation.
And to add to all this, in the early part of 2020 astronomers observed a “burst” of gravitational waves
coming from the area near the star,
which has really got astronomers wondering what the heck is going on.
One of the prevailing theories to explain all of this seemingly unexplainable behavior
is that the star is about to go supernova.
If that’s the case, that means it’s been triggered into runaway nuclear fusion,
a process which would entail the star gobbling up its remaining fuel until its depleted core collapses.
Ultimately that would lead to the brightest supernova ever observed,
turning about as bright as the moon within just a few days
and casting shadows here on Earth.
Supernovae are undoubtedly some of the most defining events in our understanding of the cosmos,
and because they’re so few and far between, observing one is a huge deal.
The last supernova to be discovered in our own solar system was Kepler's Star,
which Johannes Kepler observed way back in 1604.
This sighting convinced him and others that the heavens weren’t fixed
and it still blows our minds today, over 400 years later.
Since then we’ve gotten better at confirming these astronomical events,
like the supernova that took place back in 1987,
when light from a star that died in a nearby constellation 50,000 years prior finally reached Earth.
So if Betelgeuse is indeed headed towards its demise, then astronomically speaking,
this explosion could be imminent,
happening anytime within the next few thousand years or the next 100,000.
Unfortunately not much else is known, except that more observational studies and models are definitely needed.
But there’s one final twist to the Betelguese saga,
and it involves something that we’re a little bit more certain about:
the star is expected to cross paths with a bunch of interstellar dust within the next few thousand years,
crashing into the wall at a rate of about 30 kilometers per second.
No matter what the future holds for Betelgeuse, it seems only fitting for a star of this stature
to go out with a BIG bang!
And we’re definitely here for it.
Even if we might not be, you know, actually here for it.
I will be dead.
Curious to observe Betelguese’s changes yourself?
If you’re in the northern hemisphere, just look up, no instruments are needed!
Let us know what you see in the comments below,
and if there’s another stellar discovery that you’d like to see us cover.
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As always, thanks for watching and we’ll see you next time.