[Nuclear1]

http://www.huffingtonpost.com/2011/01/20/two-suns-twin-stars_n_811864.html

Earth could be getting a second sun, at least temporarily.

Dr. Brad Carter, Senior Lecturer of Physics at the University of Southern Queensland, outlined the scenario to news.com.au. Betelgeuse, one of the night sky's brightest stars, is losing mass, indicating it is collapsing. It could run out of fuel and go super-nova at any time.

When that happens, for at least a few weeks, we'd see a second sun, Carter says. There may also be no night during that timeframe.

The Star Wars-esque scenario could happen by 2012, Carter says... or it could take longer. The explosion could also cause a neutron star or result in the formation of a black hole 1300 light years from Earth, reports news.com.au.

[Flipside]

The Star Wars-esque scenario could happen by 2012, Carter says... or it could take longer

-1 for using the 2012 date to try and promote the event. This has been predicted for ages, and there's no reason for it to be 2012 any more than this year or 2013.

[iamzack]

why would there be no night? is it gonna be on the other side of earth from the sun or what?

[Flipside]

Might not be in the Northern Hemisphere, especially if it happens in Autumn, since Orion is an extremely prominent constellation here at night.

That said, I'm not certain if that is an exaggeration, but I suspect as much, it depends, obviously, on how bright the supernova is, which really can't be predicted.

[NGTM-1R]

Chinese court astronomy records at least one supernova which basically wiped out nighttime for three days. It's not only possible, it's happened before.

It would depend on the season, but Orion is visible pretty much all night during the winter in the northern hemisphere.

[Flipside]

There was also the 1604 daylight supernova that created the crab nebula, as I said, possible, but 'turning night into day' is possibly a very poetic way of putting it, certainly, the ambient light factors would be up, but would it truly resemble 'day', or just night with a very bright moon?

edit: That said, looking at the effects of large meteors, it's not entirely impossible that we are talking a full blue-sky day here...

http://www.youtube.com/watch?v=_bJ9_XnqLOI

[General Battuta]

It could happen tomorrow or in ten thousand years. No reason to get excited.

[Flipside]

Oh, I'm excited, hope it happens soon, but I won't hold my breath either.

I note on youTube people are already getting completely the wrong idea about black holes....

[watsisname]

Ah yes, I think we looked into this before and found a supernova of Betelgeuse should appear slightly less bright than a full moon.  So it's not quite a "turn night into day" kind of thing, though it would be pretty brilliant point of light in the sky.  If anyone's seen an Iridium Satellite Flare, this would be a few magnitudes brighter than the brightest of those.  In other words, quite blatantly obvious in the night sky, and visible even in the daytime sky.

I just hope, if it goes off in our lifetimes, that it doesn't go off between June and August, as that's when Betelgeuse appears closest to the sun.  Any other time of year and it'd be easily visible during at least some part of night.

[iamzack]

i hope it goes off tomorrow and turns into a black hole and sucks up the whole universe that would be cool

[MR_T3D]

i hope it goes off tomorrow and turns into a black hole and sucks up the whole universe that would be cool

whoa, whoa, whoa.
whoa.
there are better ways to bring us all together, a black hole is pretty close to the bottom of my list, and maybe a few others as well.

[Flipside]

Well, as I understand black holes, which admittedly, is probably a fair bit out of date, collapsing into a Black Hole won't increase the gravitational effect of Betelguise in any way, it'll still have the same gravitic strength it always had, it'll just be compacted into a much smaller focus.

For example, if every last molecule of the Sun was instantly collapsed down until it formed a black hole, it would kill life on Earth, but the Earth itself would just keep orbitting the tiny black hole as it's centre of gravity, because the strength of the gravity would be the same.

[Qent]

http://www.huffingtonpost.com/2011/01/20/two-suns-twin-stars_n_811864.html

Betelgeuse, one of the night sky's brightest stars, is losing mass, indicating it is collapsing. It could run out of fuel and go super-nova at any time.

So what they mean is we might see it run out of fuel and asplode at any time? Ugh, confusing.

[Flipside]

Anyway, I thought it was losing diameter, not mass?

[iamzack]

Well, as I understand black holes, which admittedly, is probably a fair bit out of date, collapsing into a Black Hole won't increase the gravitational effect of Betelguise in any way, it'll still have the same gravitic strength it always had, it'll just be compacted into a much smaller focus.

For example, if every last molecule of the Sun was instantly collapsed down until it formed a black hole, it would kill life on Earth, but the Earth itself would just keep orbitting the tiny black hole as it's centre of gravity, because the strength of the gravity would be the same.

i know all that it was a joke if you take me srs one more time i swear i will draw a mustache on you while you sleep

[SpardaSon21]

That statement is not intimidating because you don't know where we live.

[karajorma]

Well, as I understand black holes, which admittedly, is probably a fair bit out of date, collapsing into a Black Hole won't increase the gravitational effect of Betelguise in any way, it'll still have the same gravitic strength it always had, it'll just be compacted into a much smaller focus.

It would actually have less of an effect. Stars lose mass when they go supernova.

[watsisname]

Betelgeuse isn't so much losing mass (it is losing a bit through solar wind, but that's another matter entirely) as it is running out of viable options for fusible material in its core.  Whereas our sun is only massive enough to produce elements up to helium (and thus will die once it has too much helium in the core, ending up as a white dwarf + planetary nebula), Betelgeuse is massive enough to produce elements all the way up to iron.  But once the star has an iron core, it can fuse no further because iron doesn't give off as much energy as it takes to put into fusing it.  The result is a supernova explosion as the core of the star collapses under its own weight and the outer layers get blasted off into space by the rebounding shockwave.

The reason Betelgeuse is shrinking in diameter is because it is a red supergiant star, so it has shells of various elements around its core that are undergoing fusion, and those shells give an unstable energy output.  The star regularly contracts and expands as a result, which is why we shouldn't really be surprised that it's contracting currently.  That contraction might just be part of a cycle which will continue for quite some time, or it might be a sign that it really is about to supernova.  We simply can't tell yet because we don't have data on what the core structure is like.

What Betelgeuse's structure might look like:


Note that we don't know what the central core is made of in Betelgeuse's case.  It might be up to Oxygen, in which case there's millions of years left until it supernova's, or it might be up to iron in which case it'll explode pretty much right now.

[Mars]

Right now AKA 1000 years ago.

[Rodo]

Anyway... I've been waiting to see a nova, hope it happens during my lifetime.