Last night was a clear sky and I just had to get out and image.  Rita helped me with our rig for I was just 6 days out from my total knee replacement.  We imaged until our neighbors tree got in the way.  I decided to use the Optolong L-Enhance filter, I haven't used it much since I purchased the L-Ultimate.  I like the dark regions for they seem to have plenty of detail, more than I expected.  I was considering adding Drizzle to try and bring out more detail but I do not think I need to.  The dark regions are full of detail at least the detail I can pickup with my FLT91.  I am thinking I might visit the Rosette Nebula the next clear night and see what I can come  up with.

The Rosette Nebula (also known as Caldwell 49) is an H II region located near one end of a giant molecular cloud in the Monoceros region of the Milky Way Galaxy. The open clusterNGC 2244(Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formedfrom the nebula's matter. The nebula has been noted to be having a shape reminiscent of a human skull, and is sometimes referred to as the "Skull Nebula." It is not to be confused with NGC 246, which is also nicknamed the "Skull Nebula."[3][4]The complex has the following New General Catalogue (NGC) designations:

• NGC 2237 – Part of the nebulous region (Also used to denote whole nebula)
• NGC 2238 – Part of the nebulous region
• NGC 2239 – Part of the nebulous region (Discovered by John Herschel)
[*]NGC 2244 – The open cluster within the nebula (Discovered by John Flamsteed in 1690)[[i]citation needed]

• NGC 2246 – Part of the nebulous region

The cluster and nebula lie at a distance of 5,000 light-years from Earth[5] and measure roughly 130 light years in diameter. The radiation from the young stars excites the atoms in the nebula, causing them to emit radiation themselves producing the emission nebula we see. The mass of the nebula is estimated to be around 10,000 solar masses.A survey of the nebula with the Chandra X-ray Observatoryhas revealed the presence of numerous new-born stars inside optical Rosette Nebula and studded within a dense molecular cloud. Altogether, approximately 2500 young stars lie in this star-forming complex, including the massive O-type stars HD 46223 and HD 46150, which are primarily responsible for blowing the ionized bubble.[6][7] Most of the ongoing star-formation activity is occurring in the dense molecular cloud to the south east of the bubble.[8]A diffuse X-ray glow is also seen between the stars in the bubble, which has been attributed to a super-hot plasma with temperatures ranging from 1 to 10 million K.[9] This is significantly hotter than the 10,000 K plasmas seen in HII regions, and is likely attributed to the shock-heated winds from the massive O-type stars.On April 16, 2019 the Oklahoma Legislature passed HB1292 making the Rosette Nebula as the official state astronomical object. Oklahoma Governor Kevin Stitt signed it into law April 22, 2019.[10]

1. "NGC 2237". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-10-23.
2. Phelps, Randy L.; Ybarra, Jason E. (2005). "A Parsec-Scale Outflow in the Rosette Molecular Cloud?". The Astrophysical Journal. 627 (2): 845–849. Bibcode:2005ApJ...627..845P. doi:10.1086/430431.
3. "A hole in the heart of the Rosette Nebula". CNN. 14 February 2018.
4. "The Rosette Nebula | Astrophotography Through a Telescope".
5. 'Cambridge Deep Sky Companions - The Caldwell Objects' , S.J. O'Meara & P. Moore, Cambridge University Press, ISBN0-521-82796-5 (2002)
6. Kuhn, M. A.; et al. (2015). "The Spatial Structure of Young Stellar Clusters. II. Total Young Stellar Populations". Astrophysical Journal. 802 (1): 60. arXiv:1501.05300. Bibcode:2015ApJ...802...60K. doi:10.1088/0004-637X/802/1/60. S2CID119309858.
7. Wang, J.; et al. (2008). "AChandra Study of the Rosette Star‐forming Complex. I. The Stellar Population and Structure of the Young Open Cluster NGC 2244". Astrophysical Journal. 675 (1): 464–490. arXiv:0711.2024. Bibcode:2008ApJ...675..464W. doi:10.1086/526406. S2CID11144784.
8. Ybarra, J. E.; et al. (2013). "The Progression of Star Formation in the Rosette Molecular Cloud". Astrophysical Journal. 769 (2): 140. arXiv:1303.1226. Bibcode:2013ApJ...769..140Y. doi:10.1088/0004-637X/769/2/140. S2CID119214676.
9. Townsley, L. K.; et al. (2003). "10 MK Gas in M17 and the Rosette Nebula: X-Ray Flows in Galactic H II Regions". Astrophysical Journal. 593 (2): 874–905. arXiv:astro-ph/0305133. Bibcode:2003ApJ...593..874T. doi:10.1086/376692. S2CID16188805.
10. "Bill Information". www.oklegislature.gov. Retrieved 2019-04-17.

@information from Wikipedia

Links to more information:

https://www.constellation-guide.com/rosette-nebula/http://www.messier.seds.org/xtra/ngc/n2244.html
https://chandra.harvard.edu/press/01_releases/press_090601wind.html