Chris Peterson wrote:vern wrote:I guess I am stupid. Please explane to me how an object that is 11,000 light-years away can have its light arrive on earth in only 330 years?
The light of the supernova arrived at the earth 330 years ago. When it left the object (when the supernova "really" happened) isn't scientifically relevant, so isn't mentioned. It is customary to say that a supernova happened when it was observed, because that provides a stable and consistent time base that isn't dependent on the distance to the object (which is uncertain).
Vern, I've asked the same question myself. It's not a stupid question.
Astronomical distance (for instance this star is estimated to be 11,000 light years away) and the time span over which a supernova remnant develops (in this case we are seeing the remnant 330 years after the supernova explosion) are just two different frames of reference. If it helps, you can think of the supernova explosion as having happened 11,000 + 0 years ago, and the currently observed remnant happening now, 11,000 + 330 years after the explosion. But the 11,000 light year distance figure may change as we gain more information, and anyway, 0 years and 330 years are easier figures to work with. And if you're interested in understanding how supernova remnants develop over time, the fact that we're currently observing this one at 330 years old is the number you most care about.
(Rereading this, I see it's just a longer restatement of what Chris said, but I hope it helps anyway.)
May all beings be happy, peaceful, and free.