Tag: Rosette nebula

NGC 2237 Rosette Nebula

January 12, 2022
H II nebula
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I couldn’t imagine a better final object for the winter season. Rosette Nebula is my favorite H II region in the constellation Monoceros. At the same time, I used this deep-space object to test my portable Newtonian telescope with my new monochromatic camera ZWO ASI 2600MM. Well compared to the previous setup, this camera has much smaller pixels, which increases the requirements for the optics, specifically for the coma corrector. I am not happy with the star shape and for my planned trip to Namibia, I will try to find a portable refractor.

Here is a “fake” Hubble palette (SII, Ha, OIII):

And here more realistic bi-color variant (Ha, OIII, OIII)

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length570 mm
MountRainbow Astro RST 135
AutoguidingZWO 174MM, QHY Mini Guide Scope
CameraZWO 2600MM @-10°C
CorrectorMaxField coma corrector
FiltersAntlia Ha, OIII, SII 3 nm
Exposure94x300s, Gain 100, bin 1×1,
Date2022-01-12

NGC 2237 Rosette Nebula

March 30, 2019
H II nebula
1 Comment

Rosette Nebula is a giant cloud of hydrogen gas. The gas is ionized by the star cluster located in the middle and therefore emits the light. Circular shape and the color correspond to the name – the rose. The cluster in the middle can be observed even by using small telescope, but the nebulosity is very dim, therefore in order to see it, one would need perfectly dark sky and very large telescope with low magnification. It’s definitely easier to photograph the nebulosity. My previous photo was done through the narrow band filters, which suppress the light pollution and increases the contrast of the picture. Now I tried it with normal one shot color camera and I must conclude that it went quite well.

Technical details:

TelescopeNewton 150/600 mm
Aperture150 mm
Focal length630 mm
MountAvalon M-Zero
AutoguidingZWO 174MM, Guidescope 30 mm
CameraZWO 071 Pro @-10°C
CorrectorExplore Scientific HR
FiltersAstronomik L-1 - UV IR Block Filter
Exposure16x300s, Gain 94, bin 1x1,
Date2019-03-30

NGC2237 Rosette nebula

February 17, 2016
H II nebula
1 Comment

Another place where the stars are born is called Rosette nebula. It is a cloud of hydrogen gas, located 5000 light years from Earth in constellation Monoceros (unicorn). The diameter of this nebula is 50 light years.

This time I processed collected data by two different ways. Basic data are three monochromatic pictures captured through narrow band filters: Hydrogen alpha, Oxygen OIII and Sulfur SII.

First technique is called Hubble pallet – natural color of H alpha is red, but it’s inserted into green channel, oxygen is blue, therefore ends in blue channel and sulfur is even more “red” than the red color, therefore lands in red channel. After many different post-processing steps the final picture looks like this:

NGC2237-Rosette-2016-02-10-360s-40C-17Ha-19OIII-10SII-FL730-Hub

Second technique is more realistic for the human eyes and brain, and requires pixel math. H alpha is red, SII even more, therefore the combination of this pictures (SII + 0.8*H alpha) will end up in red channel. Green channel is a combination of 0.075*H alpha + OIII. Finally blue channel is just OIII.

NGC2237-Rosette-2016-02-10-360s-40C-17Ha-19OIII-10SII-FL730-Tri

I am quite curious which picture you like more…

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