This week we can witness, first hand, a supernova that was just discovered in the Pinwheel Galaxy. A supernova is an explosion that marks the end of the life of a star, and usually these fiery events emit a great deal of light, brighter than anything else in the region for a short period of time. In this case, the star was a white dwarf of similar mass to our own Sun, but located 21 million light years away in a relatively-close galaxy. It is brightening and will be visible at its peak this weekend. However, you will still need patience and some kind of optical aid (telescope or binoculars) to see this.
The Pinwheel Galaxy (also known as M101) is located near the Big Dipper, quite high in the sky after sunset, so use the handle of the Big Dipper to help you located the Pinwheel Galaxy. Supernova discoverer Peter Nugent of Berkeley explains how to find the Supernova in this short video. To set expectations, the supernova will be a bright spot of light, similar to a star, so don't expect to see a vast region of glowing gas and colors, but nonetheless, you can be assured that the light you are seeing has been traveling for 21 million years directly from one of the most violent, cataclysmic places in our universe, at a moment just after a star's life has ended and new matter has been created. That is a good thought to ponder as you search for the supernova.
Good luck, and leave a message if you find it!