2017 / Narrowband / Nebula

The Rosette Nebula in Hubble Palette

I will admit it has been a while since I have posted a new image. Between looking after my businesses, family life and the light pollution advocacy work I do it’s not always easy to find time to image new data and process it… then add to this very few good clear nights, equipment issues and the full moon!

During March and April of 2017 I was able to get some narrowband hydrogen-alpha (Ha) data from my driveway in Kitchener, Ontario, using my William Optics Zenithstar 71 APO refractor and the ASI1600 monochrome cooled camera.

Rosette nebula narrowband Ha image taken with Zenithstar71 refractor and ASI1600mm-c camera
H-Alpha data of the Rosette nebula taken from my driveway in Kitchener, Ontario, using the Zenithstar71 APO refractor and ASI1600MM-Cooled camera.

The data was taken on different nights and transparency and seeing varied. I chucked a good portion of the data being sub-par and what I kept gave me this Ha image.

I also had collected in March 2016 and in February 2017, narrowband data (Ha, OIII and SII) on the Rosette Nebula using a remote internet telescope located in New Mexico, USA. This Takahashi FSQ106 APO refractor was paired with an SBIG STL11000M CCD camera. These are the resulting narrowband images from this data:

Hydrogen-alpha (Ha)
Hydrogen-alpha (Ha)
Rosette-O3-Takahashi FSQ106-STL11000M-NM
Oxygen III (OIII)
Sulphur II (SII)

Using all of this narrowband data I was able to produce this splendid false colour image. This is also known as the Hubble Palette. The data was processed using PixInsight and has a synthetic luminance applied to the combined Ha, OIII and SII masters.

Click image above for higher resolution version

The Rosette Nebula is located ~5000 light years from Earth and is ~50 light years wide. It is a Winter deep sky target located in the constellation Monoceros which is next to the better known constellation of Orion the hunter.

The designation NGC 2237 is used to described the large spherical nebulosity while at the center is the open cluster NGC 2244. This region of space has young stars that stimulate the atoms in the nebula. This causes those atoms to emit radiation themselves producing the glowing emission nebula we see.

While the open cluster at the center of the Rosette Nebula is visible with binoculars and small telescopes, the nebulosity is much more difficult to see visually. Requiring a dark site away from light pollution and a large telescope.

This narrowband image is a composite of the masters resulting from the three different narrowband filters used to collect the data. It is a total of 5.5 hours.

Imaged from Kitchener, Ontario, Canada and New Mexico, USA

William Optics 71mm APO refractor, 335mm FL and a Takahashi FSQ106 ED refractor, 530mm FL

ASI 1600 monochrome cooled cmos camera with XGYL filter wheel and Optolong H-Alpha 7nm filter, SBIG STL11000M CCD camera with internal FW

330min total of Hydrogen-Alpha, Oxygen III, Sulphur II. Synthetic luminance channel.

Processing: Pixinsight


Clear skies everyone!

Shawn Nielsen

My story began nearly 40 years ago looking up at the Moon with a small collapsible telescope my Father had. Encouraged by my parents, who bought me my very own telescope, a 4.5" reflector, I began to explore the night sky from my family home backyard. Today I do astrophotography from my home in Kitchener, Ontario and also with remote telescopes located in New Mexico and Australia. Some of my images have won awards and have been featured online and in magazines.

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