narrowband


Cone & Fox Fur, +2

Two years after capturing the hydrogen channel of this image and five months after the last time I was able to do any astro-photography, I have finally managed to finish this image of the Cone and Fox Fur Nebulae: You might notice that this doesn’t look exactly like the NASA APOD image I referenced in my last post (https://apod.nasa.gov/apod/ap161224.html).  Aside from the rotation, it is mostly different in that this is a narrowband image, while the APOD image is (or appears to be) a broadband/natural color image.  In both cases the dominant features are composed of hydrogen (in red), but […]


Lagoon, Trifid, and Cat’s Paw

Last weekend’s star party was relatively relaxing, largely because the target I was after could be photographed for only a few hours each night, so I got to bed by 2 or 2:30 each night.  The target was 3 nebulae in the constellation Sagittarius, the Lagoon (M8), Trifid (M20), and Cat’s Paw (NGC6334).  All of these are primarily emission nebulae, but are often photographed in broadband color (RGB) to include some reflection components, especially the blue region on the north side of M20.  North is down in this photo, and this blue region shows only very faintly as a light […]


A Swan of a Different Color

Here are a couple of new images from the constellation Cygnus, the swan.  Both are fairly wide views (done with the WO Star71 telescope) and both are narrowband images with somewhat unusual color rendering.  First is the North America Nebula, NGC7000: I have to explain that you may be seeing something like the shape of the United States here, with the dark “hole” being the Great Lakes region, rather than the shape of North America.  But if you turn it clockwise 90 degrees the hole becomes the Gulf of Mexico and the entire continent is included. NGC7000 is one of […]


A Tulip & a Propeller, Re-processed

My productivity for the past Winter (in terms of new astro-photos produced) was well below average, and Spring has not been kind either.  So I’ve been looking at old images to see if I could find some that might benefit from the new tricks I’ve learned in processing over the last few years.  I found these two objects, which both happen to be somewhat obscure nebulae in the constellation Cygnus. The Tulip Nebula: A closer view of the actual tulip shape (center) would make for a more colorful image, but I like the contrast of this gentle flower floating on […]


Tadpoles in Space!

IC410 is an emission nebula in the constellation Auriga, and best known for the two little squiggly shapes that look like tadpoles.  It’s an interesting target at various degrees of magnification.  At very high magnification (and better atmospheric conditions than I ever see here) you can frame just the tadpoles.  A slightly wider view would include most of the surrounding nebulosity.  This view is a bit wider yet, to include some of the extended nebulosity below and to the right of the main portion.  A very wide view could include several other nebulas (see https://wa-chur-ed.com/ic405-410-and-417/). I captured this image in […]


A New Elephant

I recently completed this new image of IC1396, the “Elephant’s Trunk Nebula” using narrowband filters and the fairly short focal length Star71 telescope.  Another version of this, from almost a year ago, was done at much higher magnification and shows just the portion that gives the nebula its name – the top center of this image. The bright red star in the lower left corner is known as the “Garnet Star” and it really is very red, but its appearance is a bit of a fluke in this image:  As is always the case with narrowband images, the colors in […]


First Image of 2016

The sky had been cloudy for what seemed to be an eternity, but we’re now in a brief period of sunny days and clear nights.  Of course, it is also very cold and windy.  The cold I can deal with by operating the observatory from inside the house as much as possible.  Wind, especially a strong jet stream, is more problematic. I’ve been shooting the California Nebula (NGC1499) for the last 2 nights, using the William Optics Star71, which is relatively insensitive to atmospheric turbulence because of its small aperture and low magnification.  The first night I captured a couple […]


California Nebula

(Updated Dec. 2017) This nebula contains all 3 of the target spectral lines, hydrogen-alpha, sulphur-2, and oxygen-3. But the O-3 signal is so weak that you could literally count the photons by hand as they arrived!  To provide some color in the processed image I could have (largely) ignored the O-3 and made a bi-color image of H-a and S-2.  Instead, I used a slight variation on a commonly used process; creating a bi-color image from S-2 and O-3 (S-2 as red and O-3 as green and blue), then applying H-a as a luminance layer over the bi-color image.  The […]