Ooh. I drive past it on my way to work each day.

“Phil Plait, well known for his Bad Astronomy blog, has also done a service to humanity by giving a ranked list of threats in his recent book Death from the Skies!: These are the Ways the World Will End. He puts the odds of fatality per lifetime from a gamma ray burst at 1 in 14,000,000—20 times lower than an asteroid impact.”

– Chris Impey, HOW IT ENDS: From You to the Universe, W. W. Norton, 2010, pp 179-180

Once a RSG starts carbon burning, the inner structural changes that lead to core collapse happen too quickly for the rest of the star to adjust very much. This defines a time scale of several thousand years over which the star more or less exhibits no gross changes before it goes SN. You are correct that you would certainly not see any chemical changes. At the same time, really massive evolved stars do appear to have large instabilities in their luminosities. I don’t think it’s well understood if any of these might be harbingers of the final collapse.

On the other hand, the neutrino emission really takes off during the final stages of nuclear burning, which is why it goes so fast from carbon burning on. Neutrino production occurs under the extremely high temperatures required to burn carbon and heavier elements, but paradoxically the star freezes to death. The neutrinos go straight out, contributing nothing to pressure support – the burning fuel is wasted. If you were close enough, you might detect the rise in neutrino emission in the final year of the star’s life – I believe that we’re close enough with present technology to see this for Alpha Ori. (Note that this emission is trivial compared to what comes out in the explosion itself.)

Some have asked if the explosion is dangerous to look at by eye. The resolution of the eye is about 2 arcminutes, and it would take a long time for the Alpha Ori SN remnant to get to this size, by which time it would be vastly fainter. The resolution of the eye would dilute the light enough to avoid damage. Looking in a telescope would be a different matter if 1) the optics are fast and 2) the expanding photosphere is still hot when it’s resolved.

Warning – pulling LOTS of stuff out of my bum, here.
I kinda doubt it, as based on what I’ve read about massive stars, (even stars as large as our own sun), they aren’t fully convective. Stars that large are even less likely to have any significant gas transport, down where nickel is being fused, to the surface, where astronomers could get spectra of the fusion products.
There might be some way to get a ballpark figure by measuring the diameter and temperature of the star over time, but I’m sure scientists would need lots more data from a lot of stars before they could establish any kind of fingerprint to look for. And even then, it’d be a ballpark figure in terms of decades at the least, I’d bet. It’d help to have neutrino detectors near the star, but that’s not really practical

Even heat transport from the core of a star that large takes a significant time – so even if there was a sudden increase or decrease in temperature of the core, we might not be able to tell for years (decades? Centuries?).
That is, until it blows up. Then things happen quite fast

Lulz, seriously.
Wow, the Mayans knew about Har Meggido in the future? They traveled to the future where they read ancient Semitic texts referring to a prophesied battle there? Incredible.

Reposted for truth.

It’s disappointing that even the correct articles aren’t mentioning that even if the star exploded in 2012, we wouldn’t see it here for another 600 years.

It would be incorrect for them to say that. Information moves at the speed of light, and the measurement of time is dependent on reference frame. That means that if you want to talk about when an event happens in any meaningful way, you have to specify the reference frame for the “when”. And that means that for any given reference frame, the time that an event happens is the time it is observed in that reference frame.

If we see the star explode in 2012, then here, in earth’s reference frame, the explosion happens in 2012. In the exploding star’s reference frame it occurs at a different time, but from that star’s reference frame, the “earth year 2012″ is a meaningless concept, and because that star and our sun are continuously moving relative to one another, the “lag” between the event and our observation of it is a continuously changing variable.

Even some more massive and /or older G type yellow dwarfs such as Alpha Centauri can outshine our Sun.

And of course, our little G type Sun today is outshining our Sun yesterday. And tomorrow it will shine just a wee bit brighter than it shines today.

Never seen the movie myself.

But it depends. The way I wrote ‘news’ – and here it must be pointed out that it was arts news, not science – there was the regular harvest once a day, with a bare glance at the item to see if it was appropriate. Then the rest of the day was writing up actual items, but short ones, with a quick browse for background info; or feature items, which were researched over a couple of months.

I’m not suggesting it’s all automated: just pointing out that it’s common practice to cast a net for other news items on other sites. Especially if those other sites happen to be sisters of your parent company. The more people that see your ‘original’ content, the better, so it ends up appearing everywhere. Double the content for half the price.

I will also add that this sort of thing I’ve been employed to do, for pay, a number of times now. So it’s certainly not replacing human input. Someone still needs to make sure editorial consistency is in place, even if it just means making sure news item A fits in with your target readership.

The issue is that whilst Phil has a point to be upset at how quickly and easily myths get out of hand on the net, the blame should reside less with the journalist, and more with the parent company who places less emphasis on journalism and more on the bottom line. If I could have spent my days writing features instead of trawling harvested articles, I would. It’s far more interesting, and far more rewarding. But it’s not what I got paid for…

EDITED TO ADD: Although you’d think the arts might not be so focused on journalistic standards as science writing would be, I do believe the organisation I worked for tried its best to live up to proper research and reporting. So I don’t feel as though there should be a distinction made, at least based on my experience, because of arts vs science.

Writers and editors don’t have the time or money to investigate and write as much as they used to, so many of them ‘harvest’ news from other sites. It’s recycled news mainly because it’s easier and cheaper to scan and link to other news items than to write them yourself.

Perhaps “Desk Set” should be required viewing for such people?

http://www.imdb.com/title/tt0050307/

I find it ironic that Fox, the parent company of News.com.au (the ‘paper’ that started this), got it more right than the tabloid that originated the story.

Wait a second… It’s not Mary, it’s Jesus. It’s a sign that we’ll all meet him then because the Earth is going to be destroyed on the 21st! The Mayans were right!

Hold on, hold on… Now it looks like Phil Plait. WTF does that mean now?

I’ll be right back… My toast is ready.

It may well have gone nova already, and its light may be travelling towards us even now.

This all assumes a mass of >10 solar masses, and therefore a Type II supernova, but I don’t think that’s too contentious.

I’m a bit pissed off that after they teased the story, and got me to watch the entire 2 hour morning newscast, they never mentioned it.
But at least they didn’t report a bunch of lies and misinformation.

btw: this was channel 7, whdh, NBC in Boston.

“Personally, the worst astronomy article I remember seeing was a newspaper one where they claimed “*astrologers* had discovered a new pulsars. Aaaarrrrrgggggghhhh!!!”

In the UK, we get that sort of stupid mistake with monotonous regularity. Years ago, the local council in my home area built a public observatory, working closely with our local astronomical society. The opening ceremony was performed by Prof. Sir Arnold Wolfendale, who was then Astronomer Royal.
When the retards of our local paper reported this, they referred to our society as “Cleveland and Darlington Astrological Society, and Sir Arnold as “the Astrologer Royal”!!!!!!!
Their phone never stopped ringing the next day…