narrowband


A Baby Elephant

There are, of course, a finite number of objects that an astrophotographer can shoot.  It’s a large number, but definitely finite, and when you add restrictions (and, trust me, there are a LOT of restrictions) it can seem like a pretty small number.  So it’s encouraging to see that the same object can be photographed and processed in many different ways.  As an example, I have now photographed the Elephant’s Trunk Nebula at 3 different focal lengths; 640, 350, and now 200mm.  A much longer focal length is often used on this target to capture just the “trunk” itself (the […]


Spaghetti (with Tomato Sauce)

This is a bi-color version of the Spaghetti Nebula.  I wasn’t able to put together a suitable rig for the wider angle lens, so just captured O-3 (oxygen) with the same 200mm setup.  Hydrogen is assigned to red and oxygen to blue and green.  In other photos of this nebula I found online very few bothered with the S-2 channel, as there is so little there.  Well, as I said before, even the hydrogen is very dim.  Oxygen is even dimmer:  You can see just a hint of it in blue/green near the top. I suspect that this is pushing […]


Playing With Pacman

The sky has been mostly clear of clouds lately, but often full of smoke from forest fires.  At times it has been bad enough that we’ve had to close the windows to avoid the smell of smoke.  But I found a couple of reasonably clear nights and decided to re-shoot the Pacman Nebula (NGC281), which I haven’t done in about 5 years.  I don’t know when the “Pacman” name was first used to describe this emission nebula in Cassiopeia, but the video game character was created in 1980, so it is quite new in astronomical terms.  The nebula was first […]


Astronomy Season has (Finally) Arrived

Over the past week we’ve had some really great weather here in the Pacific Northwest, and I took advantage of the clear skies to start the astronomy season – with astro-photography, of course.  There are some dark-sky star parties going on as a write this, and I didn’t go because there is too much work to do at home, but that didn’t keep me from opening up the observatory and starting some semi-automated captures. The target this time was NGC6888, the Crescent Nebula.  This is a popular target in the Cygnus constellation, and is often photographed, both in natural color […]


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 http://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 […]