Actually before the rise of visible light there is a surge in neutrinos that can give a warning of a super-nova by as much as five days.
Then comes the light flash in all forms of electromagnetic radiation (including visible light).
Because they are massive explosions that can outshine a whole galaxy.
The most common reason why you might not see a supernova would be if it occured on the other side of the Milky Way galaxy. The dense gas and dust clouds in the galaxy make it impossible to see what's on the other side.
well what you gotta do is go home a smoke weed
Our Sun is not massive enough to end in a supernova explosion. When it nears the end of its life, it will shed its outer layers as a planetary nebula and eventually collapse into a white dwarf. Supernova explosions typically occur in massive stars that have exhausted their nuclear fuel and undergo a catastrophic collapse.
At the initial explosion, they would be spherical as pressure would be equal around the dying star. However as the expanding gases cool and mix, they can take on any shape imaginable. [See Link for pictures]
Because they are massive explosions that can outshine a whole galaxy.
It depends how far it is.Super nova's are VERY big.you would probably not see it but they are big.There were no close super nova's near earth.They were all at the other side of the galaxy or somewhere in another galaxy.
A supernova. See related question.
The most common reason why you might not see a supernova would be if it occured on the other side of the Milky Way galaxy. The dense gas and dust clouds in the galaxy make it impossible to see what's on the other side.
A supernova is when a massive star explodes. A neutron star is what can be formed after a supernova explosion. See related questions
A Supernova. See related question
They can be seen in telescopes. At least three galaxies can be seen with the naked eye, but individual stars are normally too faint to be seen. However, in the case of a supernova explosion in a nearby galaxy, it could be seen with the naked eye, too.
well what you gotta do is go home a smoke weed
Our Sun is not massive enough to end in a supernova explosion. When it nears the end of its life, it will shed its outer layers as a planetary nebula and eventually collapse into a white dwarf. Supernova explosions typically occur in massive stars that have exhausted their nuclear fuel and undergo a catastrophic collapse.
At the initial explosion, they would be spherical as pressure would be equal around the dying star. However as the expanding gases cool and mix, they can take on any shape imaginable. [See Link for pictures]
A hypernova is a more powerful and larger explosion than a supernova. It occurs when a massive star collapses and releases an immense amount of energy, much greater than that of a supernova. Hypernovae are one of the most energetic events in the universe.
Our own galaxy, the Milky Way. In general, most stars that have a proper name (as opposed to just a catalog number), and definitely all stars you can see with the naked eye (except for an occasional supernova) are part of our own galaxy.