[BradyLS]

When did the last know supernova visible to the naked eye on earth take place? What record to we have of it? Great work as always, petuniasevan!

[petuniasevan]

Depends on where you live. If you were in the Southern Hemisphere in February 1987, you were treated to the supernova 1987A in the Large Magellanic Cloud. It reached 3rd magnitude.

Unfortunately, the last Northern Hemisphere visible supernova was seen in 1604.

Sanduleak 69-202 explodes; light reaches us in 1987.

Hubble image of the expanding shockwaves from the remnant.

Kepler's Supernova was observed in the constellation Ophiuchus on October 9th 1604, when it was already brighter than other stars (didn't anyone look up in those days?) and approaching Jupiter's brightness.

Here is a ROSAT X-ray image of the remnant: