"In the outer reaches of the photosphere the density is extremely low, yet the total mass of the star is believed to be no more than 20 M☉. Consequently, the average density is less than twelve parts per billion (1.119 × 10−8) that of the Sun. Such star matter is so tenuous that Betelgeuse has often been called a "red-hot vacuum"."
> astronomers have the worst conventions in the world (for largely “historical reasons”)[2]
You don't say.
[1] http://en.wikipedia.org/wiki/Solar_mass
[2] article
This will last maybe a couple of weeks, but we don't expect it for 100K years.
Second, supernova occur quite frequently: http://en.wikipedia.org/wiki/List_of_supernovae That's not even a complete list, just the "important" ones. The odds of one occurring within our lifetime that is naked-eye visible are really quite good. The odds of it being spectacular much less so. It's likely to just be a point in the sky that wasn't there last week and won't be there next week.
The wikipedia article on near-Earth supernovae [1] suggests that Betelgeuse will be pretty safe because of its distance. But exactly how safe? What about all the delicate electronics that we've sent up to space? I suppose anything that can withstand a daily dose of solar radiation would probably be okay, but are there any specific wavelengths that could cause an issue?
That said if you had some instruments closer to the heliopause you would definitely be able to detect the shock wave at that distance. It would be faint but should be well above the noise level of other particles.
I'm not sure the Betelgeuse supernova, at a brightness around that of the full moon, would ignite fires, but I certainly wouldn't want to gaze at it with naked eyes, even at that brightness. IMHO such a light, given sufficient strength, could permanently damage the retina in your eyes.
You should know that even an impossibly tiny point source will get projected to a spot of finite size on the retina. The eye is not perfect - there is always some optical aberration. Plus, since we're talking about a star, there's also atmospheric distortion to think about.
The chances of light from Betelgeuse igniting a fire are very much zero. We're talking about light intensity about 10x lower than moonlight.
I have found that the beauty of the temporary nature of everything (especially when considered in enormous time scales) highlights the beauty of the here and now.. and the need to enjoy it. In fact, while some say not to think of the future and stay in the present, sometimes I find that imagining far into the future is precisely what brings me back to the importance of and focus on the present.
Also, there's a feeling of pure awe I get when trying to imagine the unimaginable scale of the future (for us at least). It's a specific sensation.. I am not even sure awe is the right word to describe it.
A good point, although it is fairly rare to see the sun in the night sky these days.
I remember observing this from my back garden some 10 years ago with a small telescope, but that's quite difficult now due to light polution. It's getting hard for people to see stars in many big cities, let alone fainter objects.
[1] http://eyesonthesky.com/StarCharts/FirstLightGuides.aspx
Life (Briefly) Near a Supernova:
http://www.nagt.org/files/nagt/jge/abstracts/Dutch_v53n1.pdf
I chose Betelgeuse partly as a nod to HHGG and partly for the way it read and sounded when pronounced aloud. I think of all the star names it is possibly the most beautiful and memorable.
Total click bait title.
