NGC 2903: A Missing Jewel in Leo . ... Popular among amateur astronomers, it shines in the northern spring constellation Leo, near the top of the lion's head. ... One of the brighter galaxies visible from the northern hemisphere, NGC 2903 is surprisingly missing from Charles Messier's catalog of lustrous celestial sights . This colorful image from a small ground-based telescope shows off the galaxy's gorgeous spiral arms traced by young, blue star clusters and pinkish star forming regions. ...