Astronomers have discovered a giant, 500-light-year-wide cavity between two star-forming regions in the constellations Perseus and Taurus. An ancient supernova could be the culprit.

NGC 7023, also known as the Iris Nebula, is a reflection nebula in the constellation Cepheus. It's a bright nebula that's visible in the northern sky.

Just east of Betelgeuse is the fine binocular cluster NGC 2244. But the much fainter Rosette Nebula that lies around the ...