Narrowband filters cut through the natural light pollution of the Moon, as well as man made lighting common in big cities and large towns. Even here in the country, we have neighbors on all sides with bright night lights in their yard that can be a pain to deal with. I have had my Astrodon 5nm hydrogen alpha filter for a good while, but have recently purchased the Astrodon oxygen (OIII), and sulfer (SII) filters. The first time I used these three filters I got a very bad SII signal because I shot with it very close to the full moon. Using these filters are perfectly fine to use with a full moon but I would suggest choosing a target at least 30 degrees away from the Moon when it is this big and bright. Because the SII signal was bad, and the fact that I also added RGB to my Tadpoles (IC 410), I consider my recent Rosette nebula to be my first true Hubble Palette image.
The classic Hubble Palette image, or SHO, maps the colors as Red=SII, Green=H-alpha, and Blue=OIII. First lets take a look at the different components that each filter yielded.
Here is the Hydrogen Alpha image.
Here is the SII.
And here is the OIII.
As you can see, each filter highlights a different component of the nebula. By mapping these images into the color channels as descibed above, I came up with my first true Hubble Palette image.
These were all shot with my new William Optics Star71, a 71mm 5 element apochromatic refractor operating at the native focal ratio of f/4.9 and 348mm focal length.
You can also map these colors in HSO for a more red tone which is considered more natural looking. I tried it in this palette but the colors came out very purple to my eye instead of red. So I decided to try a blend of the different components to see what I could come up with. For this next image I used a blend of 65% SII and 35% H-alpha for my Red channel, for Green I used OIII, and for blue I used a blend of 65% OIII and 35% H-alpha. Since I did not use H-alpha as a dominant channel, I lost some of the fainter outer regions but came up with a color theme that I felt was very pleasing to look at.
November and December was just awful this winter for imaging, but January was very kind. I'd like to share my images from this month here.
First up, and shot over the nights of Jan 6th and 7th, was "First Light" for my WO Star71. This is commonly called The Ghost of Cassiopeia. It is a combination of H-alpha and RGB. The dominant star in the image is gamma Cas.
On the night of January 8th I decided to take aim at a solar system target, Comet Lovejoy C/2014 Q2.
On the nights of January 9th and the 13th, I shot one of the all time favorites, the Horsehead and Flame nebula. This one is also a combination of H-alpha and RGB and was shot with the Star71.
January 16th and 17th was spent shooting the Witch Head nebula, a reflection nebula just off from the bright star Rigel in the constellation Orion. This one is LRGB with the Star71. You can certainly see where this one gets its name. The bright flare in the upper right was caused by Rigel.
Early on the morning of January 17th, after the Witch Head was too low in the west to image, I slewed to the constellation Virgo and gave this great cluster a go. I was able to capture about 3.3 hours of luminance data on this target before the Sun started coming up. The dominant group of galaxies is called Markarian's Chain, but there are MANY galaxies scattered throught the image. I hope to add some color to this one in the coming months.
After then spending a few nights gathering the narrowband data on the Rosette I changed out scopes from the Star71 to the TS 107mm triplet and captured M78 the nights of the 20th and 23rd. M78 is mostly a reflection nebula and was shot in LRGB.
On the nights of the 20th and 24th, I was able to capture this wonderful trio of galaxies in Leo, appropriately called the Leo Triplet. M65 in the top one on the right with M66 below it. On the left is NGC 3628. I was able to get some of its faint tidal tail that stretches down to the bottom of the image.
The nights of the 24th and the 26th were clear enough to get my final image of the month, the Cone nebula. This nebula is also known as the Christmas Tree Cluster and NGC 2264. The Cone nebula is a huge HII region located very near the Rosette nebula between the constellations Orion and Gemini. This one was shot in H-alpha and RGB.
As you can see, January was a great month here for imaging the stars. After just one image in November, and one in December, this was a welcome change. So 2015 is certainly off to a great start. If the coming months yield half as much imaging time it will be a great year at Little Piney Observatory.
For a closer look at these images you can click on the pictures. Or to get an even bigger and better view of these and many more images, please see my gallery on Astrobin. http://www.astrobin.com/users/rflinn68/
Clear skies everyone!
