... About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. ... Images of the star forming region W5 like those in the infrared by NASA's Wide Field Infrared Survey Explorer (WISE) satellite provide clear clues with indications that massive stars near the center of empty cavities are older than stars near the edges. ...