narrowband


The Vela Supernova Remnant

A couple of months ago I posted just the H-alpha channel of this image from the remote observatory in Australia.  The addition of O-III and S-II data makes a dramatic difference – well worth the wait! This is actually just a small portion of the Vela SNR, one of the largest and brightest SNRs in our night sky, just 1.5 degrees wide out of the full width of 8 degrees.  The supernova that produced this magnificent nebula happened about 11,000 to 12,000 years ago and was just 800 light-years from Earth in the constellation Vela. The total exposure time for […]


Vela Supernova Remnant

When a star ends its life in a supernova, huge amounts of material are ejected in all directions.  This material continues to travel outward for thousands of years, gradually producing a structure that expands and becomes more diffuse.  The Vela Nebula is one example of such a supernova remnant (SNR).  This image is just a small portion of the Vela Nebula.  If the star on the left side of this image were moved close to the center, the image would closely resemble another SNR portion, the Western Veil Nebula, also know as the Witch’s Broom: But Vela is in a […]


Patio Heart

As promised, here is a full color version of the Heart Nebula.  In addition to capturing the O-III and S-II bands, I went back to capture more H-a, so the total is about 6 hours of H-a and 3 hours each of the other 2 bands.  The color processing is (in my system of notation) H(SOO_starless), which means that I created a bi-color image with S-II as red and O-III as green and blue, then removed the stars from it, and applied the H-a image as luminance over the bi-color image.  This leaves out a lot of details, but indicates […]


I Wasn’t Expecting This

Many of the objects in the southern hemisphere sky are unfamiliar to me, including this, the “Running Chicken Nebula” (IC2944).  But I also wasn’t expecting to have another image for you so soon.  There are a bunch of targets in the queue that are RGB rather than narrowband targets, and these take longer to capture because you have to wait until there is no Moon out – on top of everything else that can get in the way of astrophotography.  Somehow, I thought this was one of those targets, but it is mostly emission nebula, and thus a narrowband target. […]


The Statue of Liberty Nebula

My latest image from Australia is NGC3576, the Statue of Liberty Nebula.  In case you don’t see it, the statue is the brighter region on the right, surrounded by swirls of color.  As with all narrowband images, this is false color, and I intentionally tweaked it to be (sort of) red, whte, and blue.  The shape of the statue is actually more apparent with a different color scheme, so I might decide to change this after spending more time with it.  The other nebula on the left is NGC3603. There is also some nice dark nebulae near the top that […]


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 […]