Back in 1181 Chinese and Japanese astronomers were able to observe a spectacular sight - a supernova explosion! I bet lots of predictions of the end of the world came with this. These are forecast by most astrologers who don't have a clue about the world around them (I am not saying they all of them don't). I don't have much respect for that field but, I guess, each to there own. Anyway back to my main theme. 3C58 is the remnant of that explosion. Something that is not visible to the eye. In fact it is not at all interesting in the visible part of the spectrum.
The interesting stuff comes when you look in X-rays - what the Chandra space telescope does! This is what you see in the visible (from DSS, http://stdatu.stsci.edu/dss/ ):
but in the X-ray band... (from Chandra; Credit: NASA/CXC/SAO/P.Slane et al.) 
Doesn't that look better!
This image is a very long exposure by Chandra (in fact 4 days and an hour!) This shows a central pulsar - a rapidly rotating neutron star that was formed when the progenitor star blew up. This is surrounded by a bright torus of X-ray emission. This sort of thing is taught and mentioned a lot but it is not often you actually get to "see" such an event - even if it is in X-rays!
For more: http://chandra.harvard.edu/photo/2004/3c58/
