Corona Borealis the Northern Crown (left) is a small constellation in the spring northern sky. To find it, look about 20° northeast of brilliant Arcturus (Alpha Boötis). The photo illustration to the right shows how T CrB may appear in outburst.Corona Borealis the Northern Crown is a small constellation in the spring northern sky. To find it, look about 20° northeast of brilliant Arcturus (Alpha Boötis).