Have I just observed a supernova? First of all, I'm from Syria. In Syria we have 70% of the night without electricity. So I love hanging out at this period of time in the night, looking up just as Prof. Stephen Hawking said to the sky, observing the beauty of the night sky. Tonight, when I was looking arbitrarily I saw a star. Suddenly its brightness increased gradually, and then this star released two big sparkles. They were more like distorted yellow or golden rings formed or more like waves.

I don't know how to express this phenomenon! Then those two sparkles disappeared, and the brightness of this star decreased very very fast until it just disappeared. It was the first time in my life I saw something like this! I just don't know what to say! This phenomenon lasted for a couple seconds.
I was shocked as much as you can imagine. I was unable to speak, totally impressed! I just cannot express my feeling! Maybe this is not a supernova! But what is that? Why did this star do that?
The odds of a supernova being visible to the naked eye is slim. Adams et al. (2013) estimated that there is a 20% chance that we will be able to see such a supernova within the next 50 years. That should give you an idea of how unlikely this is.

The vast majority of supernovae that have been discovered lately have magnitudes ranging from +20 to +16 (check out this page, updated daily). The naked eye can see objects of magnitude +6 or less, meaning that a supernova of magnitude 16 is $10^{10}$ times fainter. Powerful telescopes are needed to observe these events.

Supernovae also aren't that quick. They fade over days or weeks or months or even years. You would not see a bright, quick flash of light. I don't want to say that it's impossible . . . but it's impossible.

If this was a supernova, it's even more unlikely that you could have seen such detail. When I say that a supernova is visible to the naked eye, that just means that you can see the light from it. It doesn't mean that the structure of any gas or dust being expelled can be observed. To make out that level of detail, it would need to be quite close to Earth - and so it would definitely have been observed by astronomers and amateur stargazers in quite a few places.

So no, I don't think this was a supernova. I have no idea what you saw, but it was not what you think it is.