The last supernova in the galaxy was Kepler's star of 1604 in Ophiuchus. Or was it? You'd expect a supernova in a barred spiral of our size every 50-100 years. We haven't seen any, and it's because of that pesky dust in the way, blocking our optical view. But it looks like follow-up x-ray work from Chandra has found evidence of a 150-year old supernova in Sagittarius!
X-rays in orange, radio in blue. Reminds me of the firefox logo.
It looks like the impetus for revisiting the radio work in 1985 was that the x-rays detected by Chandra were significantly outside the 1985 radio contours implying rapid expansion. See the paper here.
P.S. Tip to General Carlessness and Bad Astronomer