No. There are two ways of generating a supernova: a star at least 8 times the mass of the sun collapsing and exploding or a white dwarf interacting or colliding with a companion star. Our sun is not massive enough to explode when it dies and does not have a companion star.
Yes, they can and many have been seen.
The last one seen was SN 2008D in the constellation Lynx, although at 88 million light years, it wouldn't have been seen with the naked eye.
See related link for a complete list.
No. Only stars bigger than about 3 times the size of our Sun have enough mass to explode as a supernova
No, only a large star can become a supernova; the earth is far too small for a supernova happen.
No - only stars can go supernova
No, only large stars go supernova when nuclear fusion breaks down. While white dwarfs can go supernova in some instances, brown dwarfs are failed stars which are not powered by nuclear fusion.
A supernova can't occur on any planet. A supernova occurs when a very large star, at least 8 times more massive than the sun dies.
Canis Majoris can refer to any number of stars which, as seen from Earth, reside within the Canis Major constellation.
A near Earth supernova [See Link] is a supernova that occurs close enough to the Earth (less than 100 light-years away) to have noticeable effects on its biosphere. Gamma rays from a supernova induce a chemical reaction in the upper atmosphere, converting molecular nitrogen into nitrogen oxides, depleting the ozone layer enough to expose the surface to harmful solar and cosmic radiation. This has been proposed as the cause of the Ordovician extinction - [See link], which resulted in the death of nearly 60% of the oceanic life on Earth. Type Ia supernova [See Link] are thought to be potentially the most dangerous if they occur close enough to the Earth. Because these supernova occur from dim, common white dwarf stars, it is likely that a supernova that could affect the Earth will occur unpredictably and take place in a star system that is not well studied. The closest known candidate is IK Pegasi [See Link] Recent estimates predict that a Type II supernova would have to be closer than 26 light-years to destroy half of the Earth's ozone layer.
That depends entirely on how far the supernova is from Earth. If it is our Sun going supernova, a little over 8 minutes. And a few Milli-seconds later all life on Earth would be gone. Any other star, it would just appear slightly brighter for a while and then disappear. It could take centuries for the light to reach us.
A supernova is an exploding star. The Earth would be instantly incinerated, of course. There is approximately zero chance this will ever happen, though. If there was a supernova near Earth ... it would depend on how near. Betelgeuse is a good candidate for a supernova "soon" (within the next million years or so). Scientists who have modeled supernova explosions don't expect it will have much of an impact. If a star nearer than Betelgeuse were to go supernova, then it might be more serious.
A supernova while the Earth was being created.
The nearest likely supernova candidate I know of is Betelgeuse, which is about 640 light years away, and is already well off the main sequence in a Red Giant phase. In order to seriously disrupt Earth, a supernova would probably have to be significantly closer than that.
There are huge spaces between stars. The biggest threat to Earth would be the gamma radiation emitted, which could sterilize the Earth from as far as 10 light-years away.
About 50 to 100 light-years as the closest safe distance between Earth and a supernova. But, if a supernova to go off within about 30 light-years of us, that would lead to major effects on the Earth, possibly mass extinctions.
No, only large stars go supernova when nuclear fusion breaks down. While white dwarfs can go supernova in some instances, brown dwarfs are failed stars which are not powered by nuclear fusion.
Heavy stars go supernova at the end of their lives.
Currently, there is no real way of knowing when a star will go supernova within a few thousand to million years. There are signs, that a star will go supernova based on physics and observations but WHEN is a problem. A star will "pulse" in a "last breath" prior to going supernova, but like death itself, no one really knows, when that last breath will happen. Betelgeuse, is experiencing those "last breaths" but when it will happen, or has happened, we will not know until we see the brilleint outburst from Earth.
Much bigger. Earth is a relatively small planet, much smaller than even a dwarf star. A supernova is a very large star exploding.
A supernova can't occur on any planet. A supernova occurs when a very large star, at least 8 times more massive than the sun dies.
Canis Majoris can refer to any number of stars which, as seen from Earth, reside within the Canis Major constellation.
A near Earth supernova [See Link] is a supernova that occurs close enough to the Earth (less than 100 light-years away) to have noticeable effects on its biosphere. Gamma rays from a supernova induce a chemical reaction in the upper atmosphere, converting molecular nitrogen into nitrogen oxides, depleting the ozone layer enough to expose the surface to harmful solar and cosmic radiation. This has been proposed as the cause of the Ordovician extinction - [See link], which resulted in the death of nearly 60% of the oceanic life on Earth. Type Ia supernova [See Link] are thought to be potentially the most dangerous if they occur close enough to the Earth. Because these supernova occur from dim, common white dwarf stars, it is likely that a supernova that could affect the Earth will occur unpredictably and take place in a star system that is not well studied. The closest known candidate is IK Pegasi [See Link] Recent estimates predict that a Type II supernova would have to be closer than 26 light-years to destroy half of the Earth's ozone layer.