Object of the Month: The Swan Nebula
Each month I highlight one of my images - giving more background to what you are looking at and how I photographed it. February 2021 is The Swan Nebula.
My Image of the beautiful SWAN NEBULA
About The Swan
This is one of the brightest and most massive star-forming regions in our galaxy - part of the reason why I just had to photograph it!
The Swan is located more than 5,000 light years away in the constellation Sagittarius. The nebula spans at least 15 light-years in diameter. The cloud of interstellar matter of which this nebula is a part is roughly 40 light-years in diameter – massive bearing in mind our entire Solar System is about 1 light year in diameter.
The intricate nebulosity from the image.
The centre of The Swan is filled with more than 100 of our galaxy’s most massive young stars. This cluster is known as NGC 6618. These stars may be many times the size of our Sun, but the youngest generations are forming deep in cocoons of dust and gas, where they are difficult to see, even with space telescopes. These young stars cause the nebula to shine due to the radiation they emit.
The Swan Nebula came to resemble the shape of a swan’s neck only relatively recently. More recent observations have revealed that its regions formed separately over multiple eras of star birth.
Imaging The Swan
An image such as this requires many tens of hours of exposure to get the detail you can see here. In this case I imaged through a range of filters for nearly 40 hours. To build up the data I take what are called ‘sub frames’ or images of a shorter duration, which I can later stack together using astronomy software. The sub frames for The Swan were 25 minutes each. It took many weeks to get enough data for The Swan as it doesn't rise very high in the northern hemisphere so it wasn't available for long each night.
After each night of imaging I review the results frame by frame and reject those that are not perfect. (Imperfections are typically caused by poor seeing, aircraft or satellites passing across the frame or software or hardware issues). I ended up with 40 hours of perfect sub frames for The Swan.
I used three filters, each designed to capture the emissions of certain ionized gasses. These are Sulphur II, Oxygen III and Hydrogen Alpha.
The next stage is a calibration routine which eliminates the unwanted artefacts caused by long duration exposures. Finally, I spend a long time processing the data to bring out the beauty and detail.
In this case it is one of the most beautiful images I have captured and created.
I hope you will get much pleasure from this image and the way it is presented as a piece of art. There are so many beautiful objects to enjoy in deep space!
Here is an example of it as a Fine Art Print.
If you would like to see the availability of The Swan then pop along to the shop right: here
There's a SPECIAL OFFER of 15% from any artwork type during February. Simply use the promo code: swan on check-out to secure your discount.