-
Asked by lwebb to Adam, Geoff, Rob, Sheila, Suzie on 16 Mar 2011 in Categories: Space.
-
Sheila Kanani answered on 15 Mar 2011:
Great question! You seem to know a lot about supernovae already!
At its current distance from Earth, such a supernova explosion would be the brightest recorded, outshining the Moon in the night sky and becoming easily visible in broad daylight. Pretty darn cool I think!
The supernova will emit neutrinos, which will reach the solar system several centuries later. Since its rotational axis is not pointed toward the Earth, Betelgeuse’s supernova is unlikely to harm us. The flash of ultraviolet radiation from the explosion will likely be weaker than the ultraviolet output of the Sun.
So in 2012 you don’t need to worry about that!
-
-
Adam Tuff answered on 15 Mar 2011:
Interesting question! Scientists have often wondered if a supernova could harm us. I think the answer is no, because of the huge distances from the Earth to Betelgeuse, about like 600 light years. Over these great distances, the amount of radiation gets weaker and weaker – if it does supernova, we will definitely be able to detect radiation from it, but it won’t be very strong at all.
-
Suzie Sheehy answered on 15 Mar 2011:
I admit I had to look this one up as I didn’t know, but its a very interesting question so thanks for asking it!
The main type of radiation you would worry about would be gamma rays – but luckily the rotation axis of Betelgeuse doesn’t point toward the Earth, so I believe we wouldn’t be hit by a gamma ray burst.
Read the article yourself if you’re interested: http://www.universetoday.com/42361/betelgeuse/
Feel free to ask more questions after you’ve read it! -
Robert Simpson answered on 16 Mar 2011:
Betelgeuse is at least 500 light years away so if it went supernova we should be alright (as long its rotational axis isn’t pointed at us – which according to a Hubble paper, it isn’t), but such an explosion would be an incredible sight from here on Earth. It would probably be visible during the day and night.
Afterwards we might have to think about what to do with Orion, since Betelgeuse is the armpit of that constellation. It would look a bit odd without it 🙂
-
Comments
lwebb commented on :
Thanks for your answers! 🙂
When we see the supernova, the light will already have taken a long time to reach us – will we detect the neutrinos at the same time, or do they travel slower than the speed of light?
Sheila commented on :
Good question about neutrino speeds. It gets a bit complicated from here. I think neutrinos can travel very close to the speed of light but then their mass changes and they change ‘flavour’.
Neutrinos have mass, but they’re still pretty lightweight. They don’t go as fast as light, they can’t since they have mass, but they come in just under that speed.
The flash of light from a supernova has to make its way out of the core of the star and through the thick outer layers, so it may take a few hours for the supernova to get bright in visible light so I imagine the neutrinos from such an explosion would get here at about the same time as the light does.
Adam commented on :
it will still take time for the neutrinos to travel to us, and if they do have mass then they must travel slower than the speed of light! Interestingly, about 99% of a supernova’s energy is in the neutrinos it emits – incredible to think what we see with our eyes is only 1% of it’s true energy!
Suzie commented on :
Neutrinos travel at *almost* the speed of light because their masses are very very tiny. Until a few years ago we didn’t even know they had a mass! It’s one of the mysteries in physics, because there’s no reason that they should have a mass or strangely morph from one type into another. They are one of my favourite particles!
So they would be a bit later than the light, but not by much!