NGC 2237 is a large emission nebula, much better known by its popular name of “Rosette” Nebula. It is a hot dust and hydrogen cloud that surrounds an open cluster (NGC 2244). In fact it is large enough so that, while NGC 2237 refers to the whole round-shaped nebula, different parts of the nebula receive different NGC denominations (like NGC 2238, 2239 and 2246). Just like NGC 7000, the Rosette is quite bright, but its low surface brightness makes it difficult to observe directly through a telescope, needing a small instrument under very dark skies.
The central open cluster formed “recently” (under cosmological standards) formed from the nebula itself.This cluster has many hot O-type stars that have wiped out the central part of the nebula, giving it the current appearance of a flower.
Name(s): NGC 2237, Caldwell 49, Rosette Nebula
Type: Emission Nebula
RA: 06h 30m 17.1s
Dec: +05º 02’ 55”
Size (arcmin): 80×50
Distance: 5,500 ly
Location: Mayhill, New Mexico, USA
Size (arcmin): 195×125
Telescope: Takahashi FSQ 106 f/5
Camera: SBIG STL11002M (4008x2672pix)
Guiding: Yes, but not recorded
Total exposure: 4 hour (L: 1 hour; RGB: 3 hours)
Processing: CCDStack, Photoshop CC 2016 and PixInsight