Found! The Actual Cause Of A Celestial Event Seen For Half A Year, In The Night Skies -- Emanating From Cassiopeia... About 800 Years Ago, In 1181 AD..

It always fires my imagination -- to think of all the light that has just recently reached us. . . many thousands of years after an event out there, in the eternity -- deep in another galaxy. But the people looking up in 1181, they saw an event as bright as Saturn -- visible to a well trained naked eye, even. They had no idea what it was, or what caused it.

And, of course, the event had actually occurred many thousands of years earlier, as Cassiopeia is about 11,000 light years away from Earth. [So we were enduring the end of the last Ice Age, when these two dwarfs actually collided.]

And yet, now after about 800 years from when its first light reach us, we've nailed down what it was, and where it happened. Here's that story -- after many years of looking at the wrong spot in the sky, too:

. . .In the year 1181 a rare supernova explosion appeared in the night sky, staying visible for 185 consecutive days. Historical records show that the supernova looked like a temporary ‘star’ in the constellation Cassiopeia shining as bright as Saturn.

Ever since, scientists have tried to find the supernova’s remnant. At first it was thought that this could be the nebula around the pulsar — the dense core of a collapse star — named 3C 58. However closer investigations revealed that the pulsar is older than supernova 1181.

In the last decade, another contender was discovered; Pa 30 is a nearly circular nebula with a central star in the constellation Cassiopeia. It is pictured here combining images from several telescopes. This composite image uses data across the electromagnetic spectrum and shows a spectacular new view of the supernova remnant. This allows us to marvel at the same object that appeared in our ancestors’ night sky more than 800 years ago. . . .

Studies of the composition of the different parts of the remnant have led scientists to believe that it was formed in a thermonuclear explosion, and more precisely a special kind of supernova called a sub-luminous Type Iax event. During this event two white dwarf stars merged, and typically no remnant is expected for this kind of explosion.

But incomplete explosions can leave a kind of ‘zombie’ star, such as the massive white dwarf star in this system. This very hot star, one of the hottest stars in the Milky Way (about 200,000 degrees Celsius), has a fast stellar wind with speeds up to 16,000 km/h. The combination of the star and the nebula makes it a unique opportunity for studying such rare explosions. . . .

Amazing. . . onward, and pulling for Marquette tonight -- smiling.

नमस्ते