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Will Betelgeuse Go Supernova in 2012?

By January 24, 2011

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I shouldn't be surprised. It seems every month or two a new theory about how the Earth will perish in December of 2012 is invented or revived.

What is surprising, however, is how widespread it has become; with several reputable news outlets such as CNN and Time, sourcing a story at the The Huffington Post, lending credence to this garbage particular theory. [Update: Since writing this post I can no longer find the Time and CNN articles. I assume someone clued them in to their error. The Huffington Post article was still live at last check though.]

The theory in question pertains to the eminent supernova that is the star Betelgeuse. You read that correctly, the star will, at some point, go supernova. But will it be in 2012?

The roughly 20 solar mass red giant is near the end of its life, meaning that it will eventually explode in a brilliant release of energy. The problem is, that we really no no clue when it will go supernova. Could be tomorrow. Could be tens of thousands of years from now. Any claim to have knowledge to the contrary is ridiculous.

So, could it happen in 2012? Sure. Will it? Statistically, not likely.

But, what if it did? If you believe the reports floating around in the internet, the exploding star will appear as a second Sun in the day time, and illuminate the night. And, worse yet, the sheer energy from the blast will have devastating effects on the Earth, particularly our atmosphere!

Uhh, no.

While an exact distance to Betelgeuse is difficult to assess (late stage red giants have tenuous outer envelopes, thwarting traditional attempts to measure distance accurately), our best estimate is that it is about 600 light-years from Earth. This is actually quite close in galactic terms (our Sun is about 8 light-minutes from Earth), so I am not totally shocked how the blogosphere has crescendoed to near panic levels over this.

But instead of panicking, let's do a little back-of-the-envelope calculation. Typically Type II supernova (a supernova resulting from the collapse of a massive star) of this size have a peak luminosity (integrated over all wavelengths) approaching about 1 billion times the power of our Sun. Quite impressive. It sounds like a lot of energy is being generated very quickly and it is. So why am I not worried?

Because the apparent luminosity (effectively the amount of energy that arrives at Earth per second) falls off with the square of the distance. In Laymen's terms, if our Sun were ten times further away from us, its apparent luminosity would be 100 times less.

So given the 600 light-year distance to Betelgeuse (about 40 million times further away from us than our Sun), the apparent peak luminosity of the supernova explosion will be roughly 0.00006% of our Sun's apparent luminosity. Clearly that is such a small percentage that the additional flux will have zero effect on our planet.

What is perhaps more interesting is the optical peak brightness (how it will appear to the naked eye). It should appear noticeably brighter than Venus on a clear night, perhaps significantly so. (I've seen reports that would indicate the brightness might rival that of the full moon, but I am somewhat skeptical of this; the numbers just don't seem to add up in my estimation.) Short story is that it will be noticeable even to those without scientific training.

Reports that are claiming that we will experience a "second sun" for several weeks in 2012 have been grossly misinformed. It may be bright enough to be visible during daylight hours, similar to the way the moon can be seen under certain conditions during the day. But two Suns? Afraid not.

Ultimately, we are not doomed when betelgeuse decides to go supernova, whenever that may be. But it will be pretty spectacular though. To actually watch the event unfold and monitor the aftermath of such a nearby source will be a huge boon for astronomy. I, for one, hope it happens sooner than later. I'd love to be around for it!

Image Credit: NASA, ESA


Comments

January 24, 2011 at 11:53 am
(1) Elvis says:

What about gamma ray burst? Are they common with Type II supernovae?

January 24, 2011 at 1:46 pm
(2) Space Guide says:

Gamma-ray bursts are still a debated phenomenon. Our best guess is that they result from the merger of two compact objects, like black holes or neutron stars. Others postulate that they arise from the collapse of super-massive stars, similar to Type II supernova, but on a much larger scale. This is not clear though. In either case, Betelgeuse is far too small to undergo such an explosion. It’s a simple matter of not having enough energy (think E=mc^2), to generate such an outburst.

On a separate note, another aspect of gamma-ray bursts is that they appear to have highly collimated beams of radiation. So, we would have to be directly in the beam’s path in order to receive the majority of the burst energy; which is fairly unlikely given the randomness of the beam direction. However, if we were in the beam path, a gamma-ray burst pretty much anywhere in our GALAXY would do us harm, no matter how far away it was. That’s how powerful they are.

January 24, 2011 at 3:40 pm
(3) Lynda says:

Hey John,
I was going to send you the article about this that I saw on FoxNews.com. I forgot to do it, but it seems that there was no need for me to do it.

Lynda

January 24, 2011 at 4:45 pm
(4) StephenP says:

I bet if we say its name three times, the Betlegeuse supernova will appear! Could you imagine if Beetlejuice from the movie was reincarnated as a weird space blob? Heíd probably look something like this http://www.youtube.com/watch?v=zvtOOGjXIfg

January 24, 2011 at 4:51 pm
(5) G Dub says:

If Betelgeuse is 600 light years away, isn’t the question really about whether it went supernova in the year 1412 (or thereabouts), and we’d be able to see its effects starting next year ?

January 24, 2011 at 5:22 pm
(6) Space Guide says:

If Betelgeuse is 600 light years away, isn’t the question really about whether it went supernova in the year 1412 (or thereabouts), and we’d be able to see its effects starting next year?

The short answer is yes. But because of the complicated business of shifting event times to the source reference frame it often creates confusion. Therefore events are usually reported in the local detected reference frame (Earth).

So while you are correct, that the question is really centered around whether it happened ~600 years ago, it is not usually discussed that way. And the fact of the matter is we won’t know when it happened (if it has) until we actually detect it here.

Thanks for asking, I realize that could have been confusing/misleading since I didn’t clarify in the post. I hope that clears things up.

January 26, 2011 at 9:12 am
(7) BJ Borkakoty says:

If we don’t know even accurately d distance of Betelgeuse, don’t you think all other stellar measurement would be fallacious.

Is it possible to predict accurately based on rate of contraction of the star or its rate of increase of Iron in its core?

January 27, 2011 at 2:44 pm
(8) John Giroux says:

It annoys me that you have to use an attention grabbing headline like “Will Betelgeuse Go Supernova in 2012?” for an article such as this. 2012 has nothing to do with the story, so why is it included???? Do you think mention of it is going to change anyone’s mind if they believe 2012 will be the end of the world???? NO! But I’m sure there will be some who may just see the headline and not bother reading it and then say to someone later “oh, I saw this article about a star going supernova in 2012″. Your entire article speaks to the chances… which are just about NIL… so why the lame headline?

January 27, 2011 at 4:39 pm
(9) Space Guide says:

I framed the title as I did because other media outlets were claiming that Betelgeuse was doing to go supernova in 2012. (The Huffington Post article I linked to made that claim for instance.) The point was not to cause panic, but to call into question that very claim. In that context I think the title is wholly appropriate. Thanks for reading.

January 27, 2011 at 5:45 pm
(10) Tom says:

SN1054 was ~ 6300 LY distant and believed to be apparent mag ~ -7. Why would a star that starts out larger than the SN1054 progenitor star, exists at approximately 1/10th the distance of SN1054, produce a peak that is less that SN1054?

Just curious.

January 27, 2011 at 8:48 pm
(11) Space Guide says:

That’s a great question! The peak magnitude of a Betelgeuse supernova would should exceed that of what was seen when the Crab Nebula was created (I’ve seen estimates in excess of magnitude -13). That said, we don’t really know what the peak brightness of the Crab was, it was most likely somewhere between magnitude -4 and -7. Most texts place it around -6. It took the crab about 2-3 months to reach its peak, and then gradually faded to below naked eye visibility during the next two years or so.

Part of the misconception is that when informed that the Crab Remnant was visible during the day, we attribute that to mean that it was as bright as the Sun. This isn’t true. It was no where near that bright. Similarly, when Betelgeuse goes supernova it will likely be visible during the day, at least at times, perhaps similar in brightness to the Moon (which is also visible sometimes during the day under the right conditions).

I should mention too that I, for one, don’t buy that it will be as bright as the Moon. Since more than 99% of the blast energy is released in the neutrino, X-ray and gamma-ray fluxes I just can’t find enough energy to achieve that level of optical brightness. But I’ve only taken a quick look at the numbers, so I may be overlooking something. And I kind of hope that I am, because that would make it even greater to behold! But it should be at least magnitude -5 or so, and a quick look at the numbers points closer to -10. (Yes, I know, that’s quite a range.)

Short story, is that it should be brighter than SN1054, probably significantly more so. But you’re right, it seems like, given the modern estimation of SN1054, you would guess that it was even brighter still. Maybe we over estimate the magnitude of SN1054? Or as I said, maybe I miscalculated. I’l have to look into that…

I’ve gone back and added a couple lines to the post to make it a bit more clear. And I’ll try and put a post together in the near future going into more detail as to how/why supernovae can be visible from Earth.

January 27, 2011 at 11:06 pm
(12) Jim says:

As far as it being visible during daylight, one just has to go back to all the ancient people who drew the Crab Nebula being born. (1024 AD ?) Plainly visible during the day for several months I believe. If the 2 parent stars and distances are (were) comparable, then we should know pretty much what to expect. Seems everyone survived that one just fine….
My 2Ę

January 31, 2011 at 3:34 am
(13) John Giroux says:

With regard to your reply (9) to my previous comment (8), it seems to me that you could have very well replaced the ? with the word NOT and shifted the order just a bit and it would have been MORE appropriate regardless of what other websites used for headlines:

As headlined: Will Betelgeuse Go Supernova In 2012?

More appropriate: Betelgeuse Will Not Go Supernova in 2012

January 31, 2011 at 1:50 pm
(14) Space Guide says:

No to be nit-picky, but a headline reading:

“Betelgeuse Will Not Go Supernova in 2012″

Is not strictly accurate. As the article states, it is entirely possible that Betelgeuse will go supernova in 2012. It is just incredibly unlikely. My intention was to put forth the title of the post as a consideration to be addressed. I suppose I could have done one of the following:

“Will Betelgeuse Go Supernova in 2012? Not Likely.”

Or

“Betelgeuse Will Not Likely Go Supernova in 2012″

But I personally don’t likely either of those. As a writer I don’t care for the flow of either one. But I guess that is debatable. Could I have framed the title differently? Sure. But keep in mind, I have a vested interest in attracting readers. So, while I never desire to mislead or trick people into reading, it is in my best interest to use a catchy headline. Especially if it feeds off of the misinformation being fed through other media outlets.

If anyone feels mislead or slighted by the title (and I say this as a general statement, not intended for anyone in particular) I apologize, as that was never my intention. But at the same time I still think it was the best choice in that it set up the article well in that it gave a question to address and besides, it was “catchy” – i.e. it sounded good and flowed well. You may disagree and that’s ok. That’s why we have a public comments section.

January 31, 2011 at 10:50 am
(15) Daniel Hudon says:

Regarding the headline, I clicked here because of it and because it was in about.com I figured the author would reliably tell us “no”.
Changing the headline “B will Not…” would have been less
sensational, but I still appreciate the author’s useful
information in the article.

Thanks,
Daniel

February 2, 2011 at 8:52 am
(16) Gary says:

Great title, great article.

February 9, 2011 at 5:32 am
(17) Rob says:

In regards to the gamma ray bursts: I thought they were mainly the after affect of a stars end that results in a black hole and the energy of the force was expelled out both ends of the black hole at the peak of its creation which gives reason to why the gamma ray bursts are generally collimated in nature.

March 14, 2011 at 2:40 pm
(18) Jordan says:

I very much enjoyed this article. the subject came to my attention from the wonders of the universe (Wotu) programme on bbc 2. I was looking for an answer over whether it would take 600 years to see the effects, though I suppose in effect it is irrelevant when the event occurred. When we see the effects is in effect when it ‘happened’ (perhaps not in a scientific sense) its a slightly philosophical question really, like a tree falling in the woods etc.

On WOTU there is the suggestion that it might be soon, but may take 1 million years for betelgeuse to ‘go supernova’ these kind of stories are brilliant for sensationalist journalism (not that this article is evidence of that.)

In a similar vein, isnt yellowstone national park due an explosion that could have potentially catasrophic effects on human existence, but due in the kind of way that it could be thousands of years away. Human concepts of time seem to struggle with the way time works in nature.

May 14, 2011 at 2:23 pm
(19) Hannah says:

Tell me John…just what makes you an “expert”? Lame…

May 14, 2011 at 2:59 pm
(20) Dr Juan says:

I would think the intensity depends on how long the supernova event lasts and at what point in that period one observes.
Do these have a standard period of activity and intensity curve or can this depend on factors such as size and composition and viewing angle wrt gamma beam?
In this case will it burn out in a few days or a few weeks or a few months and when will it be brightest?
Why is the gamma beam so focused and what would it doif we were in its path at this distance?

June 8, 2011 at 10:13 pm
(21) Dennis says:

I’ve read that the Beteleguise supernova shockwave would reach our neighborhood 100,000 years after and that would have great significance for us. Do you concur?

June 28, 2011 at 3:32 am
(22) Mike says:

Technically… Betelgeuse could have already gone supernova, and we wouldn’t know it for 600 years after it happened ;)

But I am hoping it has, and the light reaches us sometime soon… how amazing would that be? (assuming no harmful radiation destroys the planet) I bet it would peak a lot of younger generations interest in Astronomy, then what an awesome world we’d live in when they all grow up!

June 29, 2011 at 4:52 am
(23) Joe says:

Will it become a black hole? And if it does, how long does it take to turn into one? Seconds or 100,000s of years?

July 5, 2011 at 4:17 pm
(24) nick says:

they blackhole??? whould the black hole effect us???? if so or f not so how long does it take the death of a star to un fold like how long would it take for the star to go from being a super nova to being a black ole whats the time frame???

August 3, 2011 at 6:02 pm
(25) Zed says:

Awwwwww I want Betelgeuse to give me daylight 24/7 for several weeks so I can enjoy the wonderful phenomenon. The British tabloid press have done the same as parents getting kids excited about Christmas then 2 weeks before telling them that they have all become Jehovah’s Witnesses. Booooooo to the tabloid press and Boooooo to me for being so credulous and believing it. :(

August 29, 2011 at 7:02 pm
(26) James Ph. Kotsybar says:

COSMIC PREDICTION
— James Ph. Kotsybar

Betelgeuse is gonna blow!
Itís just a matter of time
Itís only ten million years old
But already well past its prime.
Betelgeuse is gonna blow:
Its hydrogen fuel is spent,
And though itís switched its diet,
And decreased by fifteen percent,
Betelgeuse is gonna blow,
And itís gonna happen soon –
Within a hundred thousand years
It will seem as bright as the moon.
When exactly, we donít know,
But Betelgeuse is gonna blow!

January 4, 2012 at 11:10 am
(27) sterom says:

it will happen when it will happen, yet its effect on earth will alter our make up it will jump start our evolution, because its energy will collide with our energy form, breaking loose the stitch which blocks the batary gland at the base of the skull at the beginning of the spinal cord

January 13, 2012 at 2:14 am
(28) Easton says:

Sterom im not even going to start to explain to you how much BS is in your statement

May 15, 2012 at 8:40 am
(29) Robert says:

Hi John,

Your right, the chances of Betelgeuse going Supernova in 2012, well it’s possible but slim.

One point of critisism on your article though, Betelgeuse is 430 Lightyears away from us instead of 600, this is a quite accurate distance.

Still not close enough to us to have real effect, only supernova’s at 50 LY distance will have to make us worrie.

Concerning the Gamma burst, Betelgeuses axes are not pointing towards us, in short even if the gamma burst would be powerfull enough to harm us, it wouldnt be coming our way.

If Betelgeuse goes supernova it could appear to us as almost a bright full moon at maximum, this would last a couple of weeks and make our nights a lot brighter, ofcourse this could have some effect on nightlife and the sales figures of blackout curtains resellers ;-)

So lets hope Betelgeuse did explode 430 Years Ago, will give a nice show.

July 5, 2012 at 9:07 am
(30) Chip Stevens says:

I have always assumed that the death of a star when the hydrogen runs out was a short time frame event as gravity overcomes the energy of the nuclear fusion and implodes before exploding as a supernova for stars beyond a particular mass.

What I am learning through Betelgeuse is that the process takes far longer than I imagined and wonder if the observations of this stars end will help us learn more about the timeframes involved.
Comments would be welcome.

August 8, 2012 at 2:18 am
(31) Cherie says:

So, it is 600 light years away. That means that it takes the light 600 years to travel to here, right.

September 21, 2012 at 5:24 pm
(32) Clark Kent says:

I read that Betelgeuse is 430 LY away. That is too far away to be a danger to us. If we see it go supernova on 21 Dec 2012 that means it actually went supernova in 1582, and it will be a mere coincidence if it is on 21 Dec 2012.

September 25, 2012 at 10:28 pm
(33) Eric says:

You have slightly in accurate info betelgeuse is actually 427 light years away

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