8th October

On this day in 1604, Johannes Kepler first sighted the supernova now called "Kepler's nova" in the constellation Ophiuchus. Kepler wrote about it in De Stella Nova in 1606. It is the most recent supernova in our galaxy to have been unquestionably observed by the naked eye.

On this day in 2010 Google released an Arf doodle (three days early).