|MadSci Network: Astronomy|
Thanks for your interesting question - you're right to say that the Sun's low mass (remember it's small as stars go) prevents it going nova. I like the thought experiment, so let's see; The first thing to say in response to your question is that there really would be a pressure wave! We can see evidence for that in other stars which have gone supernova, for example on the HST image here, which is a close up of the Cygnus loop - an expanding supernova remnant. These shockwaves slam into surrounding material and excite the atoms there, which is what produces the glow. They move incredibly quickly - with current telescopes we can watch them expand! For example, this image, taken with the Hubble Space Telescope provides a view of our nearest recent supernova, 1987A in the Large Magellenic Cloud. They move at about 1/10 the speed of light, so would take 80 minutes to reach the Earth from the Sun; and would certainly be powerful enough to rip the planet apart. There's one important caveat - there have been reports of planets orbiting pulsars, which are believed to be created in supernova explosions. It's believed to be unlikely that planets survived the explosion, so these may have formed from the debris left by the explosion.
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