© 2016 Eric Marlatt


This one is a closeup of the Rosette Nebula taken through narrowband filters. I used a hydrogen-alpha filter which is mapped to the orange/reddish tones, and Oxygen-III which is mapped to green and blue. This is about 15 hours of total exposure time taken over the last month, each exposure was 30 minutes long. Stacking and processing was done in Pixinsight.

Eric Marlatt        







The following was retrieved from Wikipedia, the free encyclopedia, at en.wikipedia.org/wiki/Rosette_Nebula on April 1, 2016

The Rosette Nebula

"The Rosette Nebula (also known as Caldwell 49) is a large, spherical (circular in appearance), H II region located near one end of a giant molecular cloud in the Monoceros region of the Milky Way Galaxy. The open cluster NGC 2244 (Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formed from the nebula's matter.

The complex has the following 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)

  • NGC 2246 – Part of the nebulous region
The cluster and nebula lie at a distance of some 5,000 light-years from Earth and measure roughly 50 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 Observatory has 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. Most of the ongoing star-formation activity is occurring in the dense molecular cloud to the south east of the bubble.

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. 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.


Observing the Rosette Nebula

The cluster of stars is visible in binoculars and quite well seen in small telescopes while the nebula itself is more difficult to spot visually and requires a telescope with a low magnification. A dark site is a must to see it. Photographically the Rosette Nebula is easier to record and it is the only way to record the red color which is not seen visually."

The license terms of this written work from Wikipedia may be found at http://creativecommons.org/licenses/by-sa/3.0/





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