Rosette Nebula (NGC 2237-2239, 2246)

Rosette Nebula

The Rosette Nebula. Image courtesy Richard Crisp.

The Rosette Nebula is a large emission nebula in the constellation Monoceros surrounding a cluster of about six hot, young O stars known as the Rosette Cluster (NGC 2244) whose radiation energizes the nebula and whose stellar winds have swept out a hollow at the center of the Rosette. The brightest parts of the nebula have their own NGC catalogue numbers.


For the amateur observer, good sky transparency and a wide field of view will show a circular faint glow around 1° in diameter. Apertures in the 20–30 centimeter range may reveal the central hole. Once identified, employ high power to scan along the nebula’s edge where brightness variations and perhaps dark material may be seen.


visual magnitude 4.8
angular size 80' × 60'
mass About 10,000 Msun
distance 3,600 light-years
position RA 06h 31.7m,
Dec +05° 04'